Timer/Counter/
Analyzers
PM6680B, PM6681, PM6681R, PM6685 & PM6685R
Programming Manual
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Table of Contents
‘C’ for National Instruments PC-IIA
Finding Your Way Through This Manual. . 1-2
Manual Conventions . . . . . . . . . . . . . . . . . 1-3
Setting Up the Instrument . . . . . . . . . . . . . 1-4
Interface Functions . . . . . . . . . . . . . . . . . . 1-5
1. Limit Testing . . . . . . . . . . . . . . . . . . . . 4-14
2. REAL Data Format . . . . . . . . . . . . . . . 4-15
3. Frequency Profiling . . . . . . . . . . . . . . . 4-17
4. Fast Sampling . . . . . . . . . . . . . . . . . . . 4-19
6. Statistics . . . . . . . . . . . . . . . . . . . . . . . 4-21
Default settings (after *RST). . . . . . . . . . . 2-8
Introduction . . . . . . . . . . . . . . . . . . . . . . . . 5-2
Measurement Function Block . . . . . . . . . . 5-3
Other Subsystems. . . . . . . . . . . . . . . . . . . 5-4
Order of Execution. . . . . . . . . . . . . . . . . . . 5-4
MEASurement Function . . . . . . . . . . . . . . 5-5
What is SCPI? . . . . . . . . . . . . . . . . . . . . . . 3-2
How does SCPI Work in the Instrument? . 3-4
Program and Response Messages . . . . . . 3-8
Command Tree . . . . . . . . . . . . . . . . . . . . 3-11
Parameters . . . . . . . . . . . . . . . . . . . . . . . 3-12
Macros. . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
Status Reporting System. . . . . . . . . . . . . 3-18
Error Reporting . . . . . . . . . . . . . . . . . . . . 3-19
Initialization and Resetting. . . . . . . . . . . . 3-21
Introduction . . . . . . . . . . . . . . . . . . . . . . . . 6-2
Calculate Subsystem. . . . . . . . . . . . . . . . . 6-3
Calibration Subsystem. . . . . . . . . . . . . . . . 6-4
Configure Function . . . . . . . . . . . . . . . . . . 6-5
Format Subsystem . . . . . . . . . . . . . . . . . . 6-6
Time Stamp Readout Format . . . . . . . . . . 6-6
Input Subsystems . . . . . . . . . . . . . . . . . . . 6-7
Measurement Function . . . . . . . . . . . . . . . 6-9
Output Subsystem. . . . . . . . . . . . . . . . . . 6-12
Sense Command Subsystems . . . . . . . . 6-14
Status Subsystem . . . . . . . . . . . . . . . . . . 6-15
Trigger/Arming Subsystem . . . . . . . . . . . 6-30
Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4-2
GW-Basic for National Instruments
Setting up the interface . . . . . . . . . . . . . . . 4-3
1. Limit Testing . . . . . . . . . . . . . . . . . . . . . 4-4
3. Frequency Profiling . . . . . . . . . . . . . . . . 4-5
4. Fast Sampling . . . . . . . . . . . . . . . . . . . . 4-7
5. Status Reporting . . . . . . . . . . . . . . . . . . 4-9
6. Statistics . . . . . . . . . . . . . . . . . . . . . . . 4-11
Introduction . . . . . . . . . . . . . . . . . . . . . . . . 7-3
Rough Trigger Subsystem Description . . . 7-4
Some Basic Commands . . . . . . . . . . . . . . 7-5
Basic Measurement Method . . . . . . . . . . . 7-7
4822 872 20081
August 2000
III
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General Speed Improvements. . . . . . . . . . 7-8
40000 measure- ments/second. . . . . . . . 7-11
Supervising a Process. . . . . . . . . . . . . . . 7-12
Speed Summary . . . . . . . . . . . . . . . . . . . 7-17
Diagnostics Subsystem . . . . . . . . 9-29
:DIAGnostic:CALibration:INPut[1|2]:HYSTeresi
Display Subsystem . . . . . . . . . . . . 9-31
:DISPlay :ENABle . . . . . . . . . . . . . . . . . . 9-32
Fetch Function. . . . . . . . . . . . . . . . 9-33
:FETCh? . . . . . . . . . . . . . . . . . . . . . . . . . 9-34
:FETCh :ARRay?. . . . . . . . . . . . . . . . . . . 9-35
Format Subsystem . . . . . . . . . . . . 9-37
:FORMat . . . . . . . . . . . . . . . . . . . . . . . . . 9-38
:FORMat . . . . . . . . . . . . . . . . . . . . . . . . . 9-38
:FORMat :FIXed . . . . . . . . . . . . . . . . . . . 9-39
:FORMat :SREGister. . . . . . . . . . . . . . . . 9-39
:FORMat :TINFormation . . . . . . . . . . . . . 9-40
Initiate Subsystem. . . . . . . . . . . . . 9-41
:INITiate :CONTinuous . . . . . . . . . . . . . . 9-42
:INITiate. . . . . . . . . . . . . . . . . . . . . . . . . . 9-42
Input Subsystems . . . . . . . . . . . . . 9-43
:INPut«[1]|2» :COUPling . . . . . . . . . . . . . 9-44
:INPut«[1]|2» :ATTenuation. . . . . . . . . . . 9-44
:INPut :HYSTeresis . . . . . . . . . . . . . . . . . 9-45
:INPut :FILTer . . . . . . . . . . . . . . . . . . . . . 9-45
:INPut :HYSTeresis :AUTO . . . . . . . . . . . 9-46
:INPut«[1]|2» :IMPedance . . . . . . . . . . . . 9-47
:INPut«[1]|2» :LEVel . . . . . . . . . . . . . . . . 9-47
:INPut :LEVel. . . . . . . . . . . . . . . . . . . . . . 9-48
:INPut :LEVel :AUTO. . . . . . . . . . . . . . . . 9-49
:INPut :LEVel :AUTO. . . . . . . . . . . . . . . . 9-50
:INPut«[1]|2|4» :SLOPe . . . . . . . . . . . . . . 9-51
:INPut2:COMMon . . . . . . . . . . . . . . . . . . 9-51
Measurement Function . . . . . . . . . 9-53
:MEASure :<Measuring Function>? . . . . 9-56
Abort. . . . . . . . . . . . . . . . . . . . . . . . . 9-3
:ABORt . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-4
Arming Subsystem . . . . . . . . . . . . . 9-5
:ARM :COUNt . . . . . . . . . . . . . . . . . . . . . . 9-6
:ARM :DELay. . . . . . . . . . . . . . . . . . . . . . . 9-7
:ARM :ECOunt. . . . . . . . . . . . . . . . . . . . . . 9-7
:ARM :LAYer2 . . . . . . . . . . . . . . . . . . . . . . 9-8
:ARM :LAYer2 :SOURce . . . . . . . . . . . . . . 9-8
:ARM :SLOPe . . . . . . . . . . . . . . . . . . . . . . 9-9
:ARM :SOURce . . . . . . . . . . . . . . . . . . . . . 9-9
:ARM :STOP :DELay. . . . . . . . . . . . . . . . 9-10
:ARM :STOP :ECOunt. . . . . . . . . . . . . . . 9-10
:ARM :STOP :SLOPe . . . . . . . . . . . . . . . 9-11
:ARM :STOP :SOURce . . . . . . . . . . . . . . 9-11
Calculate Subsystem . . . . . . . . . . 9-13
:CALCulate :AVERage :COUNt. . . . . . . . 9-14
:CALCulate :AVERage :STATe . . . . . . . . 9-14
:CALCulate :AVERage :TYPE. . . . . . . . . 9-15
:CALCulate :DATA?. . . . . . . . . . . . . . . . . 9-15
:CALCulate :IMMediate . . . . . . . . . . . . . . 9-16
:CALCulate :LIMit . . . . . . . . . . . . . . . . . . 9-16
:CALCulate :LIMit :FAIL?. . . . . . . . . . . . . 9-17
:CALCulate :LIMit :LOWer. . . . . . . . . . . . 9-17
:CALCulate :LIMit :LOWer :STATe . . . . . 9-18
:CALCulate :LIMit :UPPer . . . . . . . . . . . . 9-18
:CALCulate :LIMit :UPPer :STATe. . . . . . 9-19
:CALCulate :MATH . . . . . . . . . . . . . . . . . 9-20
:CALCulate :MATH . . . . . . . . . . . . . . . . . 9-21
:CALCulate :MATH :STATe. . . . . . . . . . . 9-21
:CALCulate :STATe. . . . . . . . . . . . . . . . . 9-22
Calibration Subsystem . . . . . . . . . 9-23
:CALibration :INTerpolator :AUTO. . . . . . 9-24
Configure Function . . . . . . . . . . . . 9-25
:CONFigure :<Measuring Function> . . . . 9-26
:MEASure :ARRay :<Measuring Function>?
:MEASure:MEMory<N>?. . . . . . . . . . . . . 9-58
:MEASure:MEMory? . . . . . . . . . . . . . . . . 9-58
:MEASure_«:DCYCle/:PDUTycycle» . . . 9-59
EXPLANATIONS OF THE MEASURING
:MEASure :FREQuency?. . . . . . . . . . . . . 9-60
:MEASure :FREQuency :BURSt? . . . . . . 9-61
:MEASure :FREQuency :PRF? . . . . . . . . 9-62
:MEASure :FALL :TIME?. . . . . . . . . . . . . 9-63
:CONFigure :ARRay :<Measuring
IV
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:MEASure :FREQuency :RATio?. . . . . . . 9-63
:MEASure [:VOLT] :MAXimum? . . . . . . . 9-64
:MEASure [:VOLT] :MINimum? . . . . . . . . 9-64
:MEASure :NWIDth? . . . . . . . . . . . . . . . . 9-65
:MEASure :PWIDth? . . . . . . . . . . . . . . . . 9-65
:MEASure_«:PDUTycycle/ :DCYCle»? . . 9-66
:MEASure_«:NDUTycycle»? . . . . . . . . . . 9-66
:MEASure :PERiod? . . . . . . . . . . . . . . . . 9-67
:MEASure :PHASe? . . . . . . . . . . . . . . . . 9-67
:MEASure [:VOLT] :PTPeak? . . . . . . . . . 9-68
:MEASure :RISE :TIME? . . . . . . . . . . . . . 9-68
:MEASure :TINTerval? . . . . . . . . . . . . . . 9-69
:MEASure :TOTalize :ACCumulated? . . . 9-70
:CONFigure :TOTalize :CONTinuous . . . 9-71
:MEASure :TOTalize :GATed? . . . . . . . . 9-72
:MEASure :TOTalize :SSTop?. . . . . . . . . 9-72
:MEASure :TOTalize :TIMed? . . . . . . . . . 9-73
Memory Subsystem . . . . . . . . . . . 9-75
:MEMory :DELete :MACRo . . . . . . . . . . . 9-76
:MEMory :FREE :SENSe?. . . . . . . . . . . . 9-76
:MEMory :FREE :MACRo? . . . . . . . . . . . 9-77
:MEMory :NSTates? . . . . . . . . . . . . . . . . 9-77
Output Subsystem . . . . . . . . . . . . 9-79
:OUTPut. . . . . . . . . . . . . . . . . . . . . . . . . . 9-80
:OUTPut :SCALe . . . . . . . . . . . . . . . . . . . 9-80
Read Function . . . . . . . . . . . . . . . . 9-81
:READ? . . . . . . . . . . . . . . . . . . . . . . . . . . 9-82
:READ:ARRay? . . . . . . . . . . . . . . . . . . . . 9-83
Sense Command Subsystem . . . . 9-85
:ACQuisition :APERture. . . . . . . . . . . . . . 9-87
:ACQuisition :APERture. . . . . . . . . . . . . . 9-87
:ACQuisition :HOFF: ECOunt . . . . . . . . . 9-88
:ACQuisition :HOFF. . . . . . . . . . . . . . . . . 9-88
:ACQuisition :HOFF :TIME . . . . . . . . . . . 9-89
:ACQuisition :HOFF :MODE . . . . . . . . . . 9-89
:ACQuisition :RESolution. . . . . . . . . . . . . 9-90
:ACQuisition :RESolution. . . . . . . . . . . . . 9-90
:AVERage :MODE. . . . . . . . . . . . . . . . . . 9-91
:AVERage :COUNt . . . . . . . . . . . . . . . . . 9-91
:FREQuency :RANGe :LOWer . . . . . . . . 9-92
:AVERage :STATe. . . . . . . . . . . . . . . . . . 9-92
:FUNCtion . . . . . . . . . . . . . . . . . . . . . . . . 9-93
:INTernal :FORMat . . . . . . . . . . . . . . . . . 9-95
:ROSCillator :SOURce . . . . . . . . . . . . . . 9-96
:SDELay . . . . . . . . . . . . . . . . . . . . . . . . . 9-96
:TOTalize :GATE . . . . . . . . . . . . . . . . . . 9-97
:VOLTage:GATed:STATe . . . . . . . . . . . . 9-97
Status Subsystem . . . . . . . . . . . . . 9-99
:STATus :DREGister0? . . . . . . . . . . . . . 9-100
:STATus :DREGister0 :ENABle. . . . . . . 9-100
:STATus :OPERation :CONDition? . . . . 9-101
:STATus :OPERation :ENABle . . . . . . . 9-102
:STATus:OPERation? . . . . . . . . . . . . . . 9-103
:STATus :PRESet . . . . . . . . . . . . . . . . . 9-103
:STATus :QUEStionable :CONDition?. . 9-104
:STATus :QUEStionable? . . . . . . . . . . . 9-105
:STATus :QUEStionable :ENABle . . . . . 9-105
System Subsystem . . . . . . . . . . . 9-107
:SYSTem :COMMunicate: GPIB: ADDRess
:SYSTem :ERRor?. . . . . . . . . . . . . . . . . . 9-108
:SYSTem :PRESet . . . . . . . . . . . . . . . . 9-109
:SYSTem :SDETect. . . . . . . . . . . . . . . . 9-109
:SYSTem :SET . . . . . . . . . . . . . . . . . . . . 9-110
:SYSTem :TIME :ELAPsed? . . . . . . . . . 9-110
:SYSTem :TOUT . . . . . . . . . . . . . . . . . . 9-111
:SYSTem :TOUT :TIME. . . . . . . . . . . . . 9-111
:SYSTem :UNPRotect . . . . . . . . . . . . . . 9-112
:SYSTem :VERSion?. . . . . . . . . . . . . . . 9-112
Test Subsystem. . . . . . . . . . . . . . 9-113
:TEST:CHECk . . . . . . . . . . . . . . . . . . . . 9-114
:TEST :SELect. . . . . . . . . . . . . . . . . . . . 9-114
Trigger Subsystem . . . . . . . . . . . 9-115
:TRIGger:COUNt . . . . . . . . . . . . . . . . . . 9-116
Common Commands . . . . . . . . . 9-117
V
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*TST? . . . . . . . . . . . . . . . . . . . . . . . . . . 9-132
VI
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Getting Started
Finding Your Way Through This Manual
You should use this Programming The ‘Programmers Reference’ Sec-
Manual
together
with
the tion of this manual contains:
PM6680B/1/5 Operators Manual.
That manual contains specifications
for the counter and explanations of
the possibilities and limitations of the
different measuring functions.
– Chapter 5, Instrument Model ex-
plains how the instrument looks
from the bus. This instrument is
not quite the same as the one used
from the front panel.
Sections
– Chapter 6 Using the Subsystems
explains more about each subsys-
tem.
The chapters in this manual are di-
vided into three sections aimed at dif-
ferent levels of reader knowledge.
– Chapter 7, How to Measure Fast
is a set of measuring situations
which the user is often confronted
with when programming a counter.
This chapter also contains infor-
mation about how to use the more
complex subsystem.
The ‘General’ Section, which can be
disregarded by the users who know
the IEEE-488 and SCPI standards:
– Chapter 2 Bus Commands for the
Benchtop User gives bus com-
mands for the front panel keys.
– Chapter 8, Error Messages con-
tains a list of all error messages
that can be generated during bus
control.
– Chapter 3 Introduction to SCPI
explains syntax data formats, sta-
tus reporting, etc.
The Practical Section of this manual
contains:
– Chapter 9, Command Reference,
This chapter gives complete infor-
mation on all commands. The sub-
systems and commands are sorted
alphabetically.
– Chapter 4, Programming Exam-
ples, with examples of typical pro-
grams for a wide variety of appli-
cations. These programs are writ-
ten in GW-basic and C.
Index
You can also use the index to get an
overview of the commands. The in-
dex is also useful when looking for
additional information on the com-
mand you are currently working with.
1-2
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Getting Started
n Alternative Expressions Giving
Different Result:
Manual
Conventions
Alternative expressions giving different
results are separated by |. For example,
On|Off means that the function may be
switched on or off.
Syntax Specification Form
This manual uses the EBNF (Extended
Backus-Naur Form) notation for describ-
ing syntax. This notation uses the follow-
ing types of symbols:
n Grouping: « »
Example:
FORMat8«ASCII|REAL»
specifies the command header FORMat
followed by a space character and either
ASCII or REAL.
n Printable Characters:
Printable characters such as Command
headers, etc., are printed just as they are,
e.g. period means that you should type
the word PERIOD.
n Optionality: [ ]
An expression placed within [ ] is op-
tional.
The following printable characters have a
special meaning and will only be used in
that meaning: # ‘ “ () : ; *
Read Chapter 3’ Introduction to SCPI’
for more information.
Example: [:VOLT]:FREQuency
means that the command FREQuency
may or may not be preceded by :VOLT.
n Repetition: { }
n Non-printable Characters:
An expression placed within { } can be
repeated zero or more times.
Two non-printable characters are used:
8
indicates the space character
(ASCII code 32).
n Equality: =
Equality is specified with =
Example: <Separator>= ,
¿
_ indicates the new line character
(ASCII code 10).
Mnemonic Conventions
n Specified Expressions: < >
Symbols and expressions that are further
specified elsewhere in this manual are
placed between the <> signs.
For example <Dec. data.>. The following
explanation is found on the same page:
“Where <Dec. data> is a four-digit num-
ber between 0.1 and 8*10-9.
n Truncation Rules
All commands can be truncated to
shortforms. The truncation rules are as
follows:
– The shortform is the first four characters of
the command.
– If the fourth character in the command is a
vowel, then the shortform is the first three
characters of the command. This rule is not
Manual Conventions 1-3
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Getting Started
used if the command is only four charac-
ters.
Setting Up the
Instrument
– If the last character in the command is a
digit, then this digit is appended to the
shortform.
Setting the GPIB Address
Examples:
The address switches on the rear panel of
the counter are set to 10 when it is deliv-
ered. The address used is displayed when
the instrument is turned on.
Longform
Shortform
:MEAS
:NEG
:MEASURE
:NEGATIVE
:DREGISTER0
:EXTERNAL4
If you want to use another bus address,
you can set these switches to any address
between 0 and 30 as shown in the follow-
ing table.
:DREG0
:EXT4
The shortform is always printed in CAPI-
TALS in this manual: :MEASure, :NEG-
ative, :DREGister0, :EXTernal4 etc.
Switch Switch
Address Settings Address Settings
0
1
00000
00001
00010
00011
00100
00101
00110
00111
01000
01001
01010
01011
01100
01101
01110
01111
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
10000
10001
10010
10011
10100
10101
10110
10111
11000
11001
11010
11011
11100
11101
11110
n Example Language
Small examples are given at various
places in the text. These examples are not
in BASIC or C, nor are they written for
any specific controller. They only contain
the characters you should send to the
counter and the responses that you should
read with the controller.
2
3
4
5
6
Example:
7
MEAS:FREQ?
SEND→
8
This means that you should program the
controller so that it addresses the counter
and outputs this string on the GPIB.
9
10
11
12
13
14
15
1.234567890E6
READ←
This means that you should program the
controller so that it can receive this data
from the GPIB, then address the counter
and read the data.
1-4 Setting Up the Instrument
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Getting Started
The address can also be set via a GPIB
command or from the AUX MENU on
the PM6680B/1/5. The set address is
stored in nonvolatile memory and re-
mains until you change it.
n Summary
Description,
Code
SH1
AH1
C0
Source handshake,
Acceptor handshake,
Control function,
Talker Function,
Listener function,
Service request,
Remote/local function,
Parallel poll,
Power-on
When turned on, the counter starts with
the setting it had when turned off.
T6
L4
n Standby
SR1
RL1
PP0
DC1
DT1
E2
When the counter is in REMOTE mode,
you cannot switch it off. You must first
enable Local control by pressing LO-
CAL.
Device clear function,
Device trigger function,
Bus drivers,
Testing the Bus
To test that the instrument is operational
via the bus, use *IDN? to identify the in- n SH1 and AH1
strument and *OPT? to identify which
options are installed. (See ‘System Sub-
system’ , *IDN? and *OPT?)
These simply mean that the counter can
exchange data with other instruments or a
controller using the bus handshake lines:
DAV, NRFD, NADC.
Interface Functions
n Control Function, C0
The counter does not function as a con-
troller.
What can I do with the Bus?
All the capabilities of the interface for the
PM6680B-series are explained below.
n Talker Function, T6
The counter can send responses and the
results of its measurements to other de-
vices or to the controller. T6 means that it
has the following functions:
– Basic talker.
– No talker only.
– It can send out a status byte as response to
a serial poll from the controller.
– Automatic un-addressing as a talker when
it is addressed as a listener.
Interface Functions 1-5
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Getting Started
cal-lock-out function, can disable the LO-
CAL button on the front panel.
n Listener Function, L4
The counter can receive programming in-
structions from the controller. L4 means
that it has the following functions:
n Parallel Poll, PP0
The counter does not have any parallel
poll facility.
– Basic listener.
– No listen only.
n Device Clear, DC1
– Automatic un-addressing as listener when
addressed as a talker.
The controller can reset the counter via
interface message DCL (Device clear) or
SDC (Selective Device Clear).
n
Service Request, SR1
The counter can call for attention from
the controller, e.g., when a measurement
is completed and a result is available.
n Device Trigger, DT1
You can start a new measurement from
the controller via interface message GET
(Group Execute Trigger).
n Remote/Local, RL1
You can control the counter manually (lo-
cally) from the front panel or remotely
from the controller. The LLO, lo-
n Bus Drivers, E2
The GPIB interface has tri-state bus driv-
ers.
1-6 Interface Functions
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Bus Commands for the Benchtop User
:INP:FILT8ON|OFF
:INP:IMP850|1E6
:INP:SLOP8POS|NEG
Switches on or off
the 100kHz LP-filter
Sets the input imped-
ance 50Ω or 1MΩ
Positive or negative trig-
ger slope
:INP:ATT81|10
:INP:COUP8AC|DC
:INP:LEV8<level>
Attenuation 1X
or 10X
Level can be set to between
–5.1 to + 5.1 V when at-
tenuator is set to 1X, and
–51 to + 51 V when attenu-
ator is set to 10X
F
Q
U
E
N
C
Y
R
E
F
E
R
E
N
C
E
/
C
O
5
U
N
T
E
R
/
C
A
L
I
B
R
A
T
P
M
6
6
8R
E 1
R
SWAP AB
Not used via the bus, you ad-
dress the input you want to
measure on directly
:INP2:SLOP_POS|NEG
R
E
F
L
O
C
A
L
E
X
T
I
N
P
U
T
A
S
W
A
P
I
N
P
U
T
B
H
O
L
D
O
F
F
A
D
P
J
R
E
S
R
E
T
E
F
F
I
L
T
5
E
0
R
/
1
M
/
A
B
/
5
0
/
1
C
M
O
M
C
A
H
E
C
K
O
N
U
S
N
L
O
C
K
/
T
R
I
G
G
E
R
L
E
V
E
L
T
O
T
T
A
N
D
B
Y
O
N
1
X
/
A
1
C
0
X
/
S
D
E
C
T
A
A
U
T
O
S
A
E
C
T
/
B
1
D
X
C
/
S
1
T
0
/
X
S
T
O
P
S
E
T
:INP:LEV:AUTO8ON|OFF|ONCE
:INP2:LEV:AUTO8ON|OFF|ONCE
:INP2:ATT81|10
Note that AUTO is selected indi-
vidually for A and B inputs
:INP2:COM8MON|OFF
:INP2:COUP8AC|DC
:INP2:IMP850|1E6
:INP2:LEV8<level>
2-2 Error Code
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Bus Commands for the Benchtop User
:DISPL:ENAB8ON|OFF
:ROSC:SOUR8INT|EXT*
:SYST:PRES or *RST
Presets the counter to default
F
Q
U
E
N
C
Y
R
E
F
E
R
E
N
C
E
/
C
O
5
0
U
N
T
E
R
/
C
A
L
I
B
R
P
M
6
6
8R
E 1
R
R
E
F
L
O
C
A
L
E
X
T
I
N
P
U
T
A
S
W
A
P
I
N
P
U
T
B
H
O
L
D
O
F
F
A
D
P
J
R
E
S
R
E
T
E
F
F
I
L
T
5
E
0
R
/
1
M
/
A
B
/
5
0
/
1
C
M
O
M
C
A
H
E
C
K
O
N
U
S
N
L
O
C
K
/
T
R
I
G
G
E
R
L
E
V
E
L
T
O
T
T
A
N
D
B
Y
O
N
1
X
/
A
1
C
0
X
/
S
D
E
C
T
A
A
U
T
O
S
A
E
C
T
/
B
1
D
X
C
/
S
1
T
0
/
X
S
T
O
P
S
E
T
:TEST:CHEC8ON|OFF
:TOT:GAT8ON|OFF*
:ACQ:HOFF8ON|OFF*
:ACQ:HOFF:TIME8<time>
Time can be set between
200E–9 and 1.6
*
These commands are from the
SENSE subsystem
*
Error Code 2-3
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Bus Commands for the Benchtop User
:FUNC8"functionc8hannel,channel"
*
:ACQ:APER8<time>
Function and channel is explained on page 2-6
Time can be set to:
0.8E–6, 1.6E–6, 3.2
E–6,
6.4E–6 12.8E–6
The functions in the auxiliary
menu tree are found in many
different subsystem command
trees, for instance the No. of
samples for statistics is in the
Calculate subsystem
and 50E–6 to 400
*
:AVER:STAT8OFF|ON
OFF gives SINGLE
gives
ON
AVER-
R
U
B
I
D
I
U
M
A
T
O
M
I
C
R
E
F
E
R
E
N
C
E
C
L
O
C
5
0
p
s
/
3
0
0
M
H
z
F
U
N
C
T
I
O
M
N
E
A
S
U
R
E
M
P
E
R
N
O
T
C
E
S
S
D
A
T
A
E
N
T
R
Y
T
I
M
E
H
O
L
D
S
T
A
R
T
A
M
R
A
M
T
H
-
1
7
4
1
0
8
9
X
n
A
U
X
M
E
N
U
M
E
N
U
S
I
N
G
R
L
E
E
S
T
A
S
R
T
T
O
P
A
R
S
M
T
A
T
5
2
6
3
X
o
G
A
T
E
S
E
L
E
C
T
S
E
T
K
=
T
R
I
G
T
R
I
G
F
F
L
=
+
/
-
D
C
-
3
0
0
M
H
z
A
B
C
L
E
A
R
E
E
E
N
T
E
R
M
=
M
A
X
.
1
2
V
5
r
m
0
s
3
5
0
.
1
V
M
p
S
A
V
E
R
E
C
A
L
L
:READ?
:ARM:SOUR8EXT2|EXT4
:ARM:STOP:SOUR8EXT2|EXT4
Starts
measure-
ment and
requests re-
sult
a
Switches on start arming on
input B(2) or E(4).
:ARM:SOUR8IMM
Switches on stop arming on input
B(2) or E(4).
:ARM:STOP:SOUR8IMM
Switches off start arming
:ARM:SLOP8POS|NEG
Switches off stop arming
:ARM:STOP:SLOP8POS|NEG
*
These commands are from the SENSE subsystem
2-4 Error Code
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Bus Commands for the Benchtop User
:CALC:MATH8 (<expression>)
Expression is mathematical expression
containing +, –, *, /, and XOLD
XOLD
in a mathematical ex-
pression
gives the same result ar
pressing Xn-1
:CALC:MATH:STAT8ON|OFF
Not used via bus;
:CALC:AVER:TYPE8MAX|MIN|SDEV|MEAN
Selects statistical function
enter constants di-
rectly in the mathe-
matical expression
:CALC:AVER:STAT8ON|OFF
R
U
B
I
D
I
U
M
A
T
O
M
I
C
R
E
F
E
R
E
N
C
E
C
5
0
p
s
/
3
0
0
M
H
z
F
U
N
C
T
I
O
M
N
E
A
S
U
R
E
M
P
E
R
N
O
T
C
E
S
S
D
A
T
A
E
N
T
R
Y
T
I
M
E
H
O
L
D
S
T
A
R
T
A
M
R
A
M
T
H
-
1
7
4
1
0
8
5
9
X
n
A
U
X
M
E
N
U
M
E
N
U
S
I
N
G
R
L
E
E
S
T
A
S
R
T
T
O
P
A
R
S
M
T
A
T
6
X
o
G
A
T
E
S
E
L
E
C
T
S
E
T
K
=
2
3
T
R
I
G
T
R
I
G
F
F
L
=
+
/
-
D
C
-
3
0
0
M
H
z
A
B
C
L
E
A
R
E
E
E
N
T
E
R
M
=
M
A
X
.
1
2
V
5
r
m
0
s
3
5
0
.
1
V
M
p
S
A
V
E
R
E
C
A
L
L
*SAV8<memory location>
Memory location can be any No.
between 0 and 19
*RCL8<memory location>
Error Code 2-5
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Bus Commands for the Benchtop User
:FUNC8"FREQ:RAT81,2"
:FUNC8"PER81"
:FUNC8"FREQ:RAT83,2"
:FUNC8"PWID81"
:FUNC8"FREQ83"
:FUNC8"TINT81,2"
:FUNC8"FREQ81"
:FUNC8"PHAS81,2"
REMOTE
:FUNC8"RISE|FALL:TIME81"
:FUNC8"PDUT81"
:FUNC8"TOT:GAT81,2"
:FUNC8"TOT:SST81,2"
:FUNC8"TOT81,2"
This segment is
on when the in-
strument is con-
trolled from
GPIB. Press LO-
CAL to interrupt
bus control.
:FUNC8"VOLT:MAX81"
:FUNC8"VOLT:MIN81"
:FUNC8"VOLT:PTP81"
SRQ
This segment is on
when the instrument has
sent a Service Request
via GPIB but the con-
troller has not fetched
the message.
All commands on this page are from the
SENSE subsystem
2-6 Error Code
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Bus Commands for the Benchtop User
PM6680B
I
N
P
U
T
A
9
0
V
-
2
6
5
V
I
I
N
N
P
P
U
U
T
T
B
C
O
N
1
6
8
4
I
S
R
E
1
E
E
4
8
C
8
/
I
E
C
6
2
5
I
N
T
E
R
F
A
C
E
O
F
F
A
D
D
R
E
S
H
S
1
,
A
H
1
,
T
5
,
L
4
,
S
R
1
,
A
N
A
L
O
G
L
1
,
D
1
,
D
T
1
,
E
2
O
U
T
P
U
T
O
B
O
N
P
R
I
M
A
R
Y
F
U
S
E
I
N
S
I
D
E
P
M
9
6
7
8
P
P
P
P
M
M
M
M
9
9
9
9
6
6
6
6
2
2
2
2
1
4
5
6
P
M
9
6
2
9
8
/
8
0
A
T
T
E
R
Y
1
.
6
A
T
P
P
M
M
9
9
6
6
9
9
0
1
P
M
9
6
7
F
F
_
_
_
_
_
_
_
_
_
_
_
_
_
_
P
R
O
B
E
G
A
T
E
N
1
0
M
H
R
z
E
F
E
R
E
N
E
C
X
E
M
T
C
O
M
P
T
R
I
G
M
a
d
e
i
n
S
w
e
d
e
n
O
P
E
O
U
T
I
N
A
R
V
I
E
G
W
N
L
D
E
V
E
L
A
B
A
B
O
U
T
O
U
T
E
X
T
R
E
F
M
U
N
L
O
T
T
I
P
I
L
N
I
C
E
L
R
F
A
N
N
O
T
I
N
C
L
H
G
D
E
:OUTP8ON|OFF
OUTP:SCAL8<scaling factor>
:SYST:COMM:GPIB:ADDR8<Address>
<Address> can be between 1 and 30
Input 4
:ROSC:SOUR8INT|EXT *
I
N
P
U
T
I
N
P
U
T
I
N
P
U
T
A
B
C
O
P
T
I
O
N
S
P
P
P
P
M
M
M
M
9
9
9
9
6
6
6
6
2
2
2
2
1
4
5
5
P
R
I
M
A
R
Y
F
U
S
E
1
.
6
A
T
B
9
0
V
-
2
6
5
V
I
N
S
I
D
E
5
M
H
z
R
U
B
I
D
I
U
J
M
A
T
O
M
I
C
R
L
E
F
E
R
E
N
C
E
C
L
O
C
K
O
U
T
P
U
T
S
/
1
0
M
H
z
0
.
6
V
r
m
s
I
N
5
0
I
S
R
E
E
E
4
8
8
/
I
E
C
6
2
5
I
N
T
E
R
F
A
C
E
N
I
K
M
H
1
,
A
H
1
,
T
6
,
L
4
,
S
R
1
,
L
1
,
D
C
1
,
D
T
1
,
E
2
P
R
O
B
E
C
O
M
P
V
I
E
W
L
R
3
9
4
8
4
A
N
A
L
O
G
G
A
E
T
E
X
T
R
E
F
E
R
E
N
C
E
A
B
G
N
D
B
A
O
U
T
O
P
E
N
A
R
M
I
N
T
R
I
G
L
E
V
E
L
F
H
E
D
G
PM6681R
*
This command is from the SENSE subsystem
Error Code 2-7
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Bus Commands for the Benchtop User
PARAMETER
VALUE/
SETTING
Default settings
(after *RST)
Mathematics
OFF
Sample size in Statistics 100
PARAMETER
VALUE/
SETTING
Sample size in Time In-
terval Average
100
Input A:
Mathematical constants:
Trigger level
Impedance
AUTO
1 MΩ
0V
K= and M=
1
0
L=
Manual Trigger level
(Controlled by autotrigger)
Miscellaneous:
Function
Timeout
FREQ A
Manual Attenuator
(Controlled by autotrigger)
1X
100 ms,
OFF
Coupling
Trigger slope
Filter
AC
Measuring time
Check
100 µs
OFF
Pos
OFF
Single cycle
Analog output control
Hold Off
OFF
Input B:
OFF
Trigger level
Impedance
AUTO
1 MΩ
0V
Time, OFF
Memory Protection
(Memory 10 to19)
Not
changed by
reset
Manual Trigger level
(Controlled by autotrigger)
Manual Attenuator
(Controlled by autotrigger)
1X
Auxiliary functions
Blank LSD
All switched
OFF
Coupling
DC
OFF
Trigger slope
Common
Pos
OFF
Arming:
Start
Stop
Delay
OFF
OFF
Start, Time,
OFF
Channel
Ext Arm
Input E
Statistics:
Statistics
OFF
2-8 Default settings (after *RST)
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Introduction to SCPI
Compatibility
What is SCPI?
SCPI provides two types of compatibil-
for ity: Vertical and horizontal.
SCPI
(Standard
Commands
Programmable Instruments) is a standard-
ized set of commands used to remotely
control programmable test and measure-
ment instruments. The CNT-8X firmware
contains the SCPI. It defines the syntax
and semantics that the controller must use
to communicate with the instrument.
:INPut:COUPling AC
AC
This chapter is an overview of SCPI and
shows how SCPI is used in Fluke Fre-
quency Counters and Timer/Counters.
AC
Figure 3-1
Vertical
SCPI is based on IEEE-488.2 to which it
owes much of its structure and syntax.
SCPI can, however, be used with any of
the standard interfaces, such as GPIB
(=IEC625/IEEE-488), VXI and RS-232.
This means that all instruments of the
same type have i´dentical controls. For
eample, oscilloscopes will have the
same controls for timebase, triggers and
voltage settings
Reason for SCPI
For each instrument function, SCPI de-
fines a specific command set. The advan-
tage of SCPI is that programming an
instrument is only function dependent
and no longer instrument dependent. Sev-
eral different types of instruments, for ex-
ample an oscilloscope, a counter and a
multimeter, can carry out the same func-
tion, such as frequency measurement. If
these instruments are SCPI compatible,
you can use the same commands to mea-
sure the frequency on all three instru-
ments, although there may be differences
in accuracy, resolution, speed, etc.
10.1234567890E3
:MEASure:FREQuency?
10E3
10.1E3
Figure 3-2
Hoizontal
This means that instruments of different
types that performs the same functions
have the same commands. For exam-
ple, a DMM, an oscilloscope, and a
counter can all measure frequency with
the same commands
3-2 What is SCPI?
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Introduction to SCPI
A programmer with SCPI experience,
however, will understand the meaning
and reasons of a SCPI program, because
of his knowledge of the standard.
Changes, extensions, and additions are
much easier to make in an existing appli-
cation program. SCPI is a step towards
portability of instrument programming
software and, as a consequence, it allows
the exchange of instruments.
Management and
Maintenance of Programs
SCPI simplifies maintenance and man-
agement of the programs. Today changes
and additions in a good working program
are hardly possible because of the great
diversity in program messages and instru-
ments. Programs are difficult to under-
stand for anyone other than the original
programmer. After some time even the
programmer may be unable to understand
them.
GPIB
GPIB
Interface
Response
Messages
Program
Messages
Input Buffer
Output Queue
Response
Messages
Program
Messages
Parser
Message
Exchange
Control
Parsed
Messages
Response
Formatter
Execution
Control
Instrument
Functions
Response Data
Executable
Messages
Figure 3-3
Overview of the firmware in a SCPI instrument.
What is SCPI? 3-3
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Introduction to SCPI
Message Exchange Control
protocol
How does SCPI
Work in the
Instrument?
Another important function is the Mes-
sage Exchange Control, defined by
IEEE 488.2. The Message Exchange
Control protocol specifies the interactions
between the several functional elements
that exist between the GPIB functions
and the device-specific functions, see
The functions inside an instrument that
control the operation provide SCPI com-
logical model of the message flow inside
a SCPI instrument.
The Message Exchange Control protocol
specifies how the instrument and control-
ler should exchange messages. For exam-
ple, it specifies exactly how an
instrument shall handle program and re-
sponse messages that it receives from and
returns to a controller.
When the controller sends a message to a
SCPI instrument, roughly the following
happens:
– The GPIB controller addresses the instru-
ment as listener.
– The GPIB interface function places the
message in the Input Buffer.
This protocol introduces the idea of com-
mands and queries; queries are program
messages that require the device to send a
response. When the controller does not
read this response, the device will gener-
ate a Query Error. On the other hand,
commands will not cause the device to
generate a response. When the controller
tries to read a response anyway, the de-
vice then generates a Query Error.
– The Parser fetches the message from the
Input Buffer, parses (decodes) the message,
and checks for the correct syntax. The in-
strument reports incorrect syntax by send-
ing command errors via the status system
to the controller. Moreover, the parser will
detect if the controller requires a response.
This is the case when the input message is
a query (command with a “?” appended).
The Message Exchange Control protocol
also deals with the order of execution of
program messages. It defines how to re-
spond if Command Errors, Query Errors,
Execution Errors, and Device-Specific er-
rors occur. The protocol demands that the
instrument report any violation of the
IEEE-488.2 rules to the controller, even
when it is the controller that violates
these rules.
The Parser will transfer the executable
messages to the Execution Control block
in token form (internal codes). The Exe-
cution Control block will gather the infor-
mation required for a device action and
will initiate the requested task at the ap-
propriate time. The instrument reports ex-
ecution errors via the status system over
the GPIB and places them in the Error
Queue.
The IEEE 488.2 standard defines a set of
operational states and actions to imple-
ment the message exchange protocol.
These are shown in the following table:
– When the controller addresses the instru-
ment as talker, the instrument takes data
from the Output Queue and sends it over
the GPIB to the controller.
3-4 How does SCPI Work in the Instrument?
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Introduction to SCPI
message. When the controller violates this
rule, the device will report a query error
(interrupted action).
State
IDLE
Purpose
Wait for messages
Read and execute mes-
sages
READ
– The instrument sends only one response
message for each query message. If the
query message resulted in more than one
answer, all answers will be sent in one re-
sponse message.
QUERY
Store responses to be
sent
SEND
RE-
SPONSE
DONE
Send responses
Complete sending re-
sponses
n Order of Execution
Finished sending re-
sponses
Deferred Commands
DEADLOCK The device cannot buffer
more data
Execution control collects commands un-
til the end of the message, or until it finds
a query or other special command that
forces execution. It then checks that the
setting resulting from the commands is a
valid one: No range limits are exceeded,
no coupled parameters are in conflict, etc.
If this is the case, the commands are exe-
cuted in the sequence they have been re-
ceived; otherwise, an execution error is
generated, and the commands are dis-
carded.
Action,
Untermin-
ated,
Reason
The controller attempts to
read the device without
first having sent a com-
plete query message
Interrupted, The device is interrupted
by a new program mes-
sage before it finishes
sending a response mes-
sage
This deferred execution guarantees the
following:
– All valid commands received before a
query are executed before the query is exe-
cuted.
Protocol Requirements
In addition to the above functional ele-
ments, which process the data, the mes-
sage exchange protocol has the following
characteristics:
– All queries are executed in the order they
are received.
– The order of execution of commands is never
reversed.
– The controller must end a program mes-
sage containing a query with a message
terminator before reading the response
from the device (address the device as
talker). If the controller breaks this rule,
the device will report a query error
(unterminated action).
n Sequential and Overlapped
Commands
There are two classes of commands: se-
quential and overlapped commands. All
commands in the CNT-8X counters are
sequential, that is one command finishes
before the next command executes.
– The controller must read the response to a
query in a previously (terminated) program
message before sending a new program
How does SCPI Work in the Instrument? 3-5
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Introduction to SCPI
The Counter in Remote Operation
Remote Local Protocol
n Definitions
When the Counter is in remote operation,
it disables all its local controls except the
LOCAL key.
Remote Operation
The Counter in Local Operation
When an instrument operates in remote,
all local controls, except the local key,
are disabled.
When the Counter is in local operation
the instrument is fully programmable
both from the front panel and from the
bus. If a bus message arrives while a
change is being entered from the front
panel, the front panel entry is interrupted
and the bus message is executed.
Local Operation
An instrument operates in local when it is
not in remote mode as defined above.
Local Lockout
We recommend you to use Remote mode
when using counters from the bus. If not,
the counter measures continously and the
initiation command :INIT will have no
effect.
In addition to the remote state, an instru-
ment can be set to remote with ‘local
lockout’. This disables the return-to-local
button. In theory, the state local with lo-
cal lockout is also possible; then, all local
controls except the return-to-local key
are active.
3-6 How does SCPI Work in the Instrument?
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Introduction to SCPI
Program and Response Messages
The communication between the system One or more program message units
controller and the SCPI instruments con- (commands) may be sent within a simple
nected to the GPIB takes place through program message, see Fig. 3-6.
Program and Response Messages. A Pro-
gram Message is a sequence of one or
more commands sent from the controller
to an instrument. Conversely, a Response
Message is the data from the instrument
to the controller.
;
<
P
r
o
g
r
a
m
M
e
s
s
a
g
e
U
n
i
t
>
Fig 3-6
Syntax of a terminated
Program Message.
C
o
n
t
r
o
l
l
e
r
D
e
v
i
c
e
C
o
m
m
a
n
d
s The ¿ is the pmt (program message
terminator) and it must be one of the fol-
lowing codes:
P
r
o
g
r
a
m
M
e
s
s
a
g
e
s
Q
u
e
r
i
e
s
R
e
p
o
s
n
s
e
g
e
M
s
e
s
s
a
Figure 3-4
Program and response
messages.
¿
NL^END
This is <new line>
code sent concur-
rently with the
END message on
the GPIB.
The GPIB controller instructs the device
through program messages. The device
will only send responses when explicitly
requested to do so; that is, when the con-
troller sends a query. Queries are recog-
nized by the question mark at the end of
the header, for example: *IDN? (requests
the instrument to send identity data).
NL
This is the <new
line> code.
<dab>^END
This is the END
message sent
concurrently with
the last data byte
<dab>.
Syntax and Style
n Syntax of Program Messages
NL is the same as the ASCII LF
(<line feed> = ASCII 10decimal ).
The END message is sent via the
EOI-line of the GPIB.
The ^ character stands for ‘at the
same time as’.
+
A command or query is called a program
message unit. A program message unit
consists of a header followed by one or
,
<
S
p
a
c
e
>
<
H
e
a
d
e
r
>
<
P
a
r
a
m
e
t
e
r
>
Figure 3-5
Syntax of a Program
Message Unit.
Program and Response Messages 3-7
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Introduction to SCPI
Most controller programming languages root level keyword, representing the high-
send these terminators automatically, but est hierarchical level in the command
allow changing it. So make sure that the tree.
terminator is as above.
The keywords following represent
Example of a terminated program mes- subnodes under the root node. See
sage:
:INP:IMP
more details of this subject.
1E6;:ACQ:APER
0.1NL^END
Forgiving Listening
program message unit
terminator
The syntax specification of a command is
as follows:
program message unit
This program message consists of two
message units. The unit separator (semi-
colon) separates message units.
ACQuisition:APERture8<numeric value>
Where: ACQ and APER specify the
shortform, and ACQuisition and APER-
ture specify the longform. However,
ACQU or APERT are not allowed and
cause a command error.
Basically there are two types of com-
mands:
Common Commands
In program messages either the long or
the shortform may be used in upper or
lower case letters. You may even mix up-
per and lower case. There is no semantic
difference between upper and lower case
in program messages. This instrument be-
havior is called forgiving listening.
The common command header starts with
the asterisk character (*), for example
*RST.
SCPI Commands
SCPI command headers may consist of
several keywords (mnemonics), separated
by the colon character (:).
For example, an application program may
send the following characters over the
bus:
E
n
d
n
o
d
e
R
o
o
t
S
u
b
n
o
d
e
s
iNp:ImP81E6
SEND→
The example shows the shortform used in
a mix of upper and lower case
Input:Imp81E6
SEND→
The example shows the a mix of long and
shortform anda mixe of upper and lower
case.
Figure 3-7
The SCPI command tree.
Each keyword in a SCPI command
header represents a node in the SCPI
command tree. The leftmost keyword
(INPut in the previous example) is the
3-8 Program and Response Messages
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Introduction to SCPI
Notation Habit in Command Syntax
;
To clarify the difference between short
and longform, the shortform in a syntax
specification is shown in upper case let-
ters and the remaining part of the
longform in lower case letters.
<
R
e
s
p
o
n
s
M
e
s
s
a
g
e
U
n
i
t
>
Fig 3-9
Syntax of a Terminated
Response Message.
Notice however, that this does not specify
the use of upper and lower case charac-
ters in the message that you actually sent.
Upper and lower case letters, as used in
syntax specifications, are only a notation
convention to ease the distinction be-
tween long and shortform.
The response message terminator (rmt) is
always NL^END, where:
NL^END is <new line> code (equal to
<line feed> code = ASCII 10 decimal)
sent concurrently with the END message.
The END message is sent by asserting the
EOI line of the GPIB bus.
n Syntax of Response Messages
The response of a SCPI instrument to a Responses:
query (response message unit) consists of
A SCPI instrument always sends its re-
sponse data in shortform and in capitals.
one or more parameters (data elements)
as the following syntax diagram shows.
There is no header returned.
Example:
You program an instrument with the fol-
lowing command:
,
:ROSCillator:SOURce8EX-
SEND→
Ternal
<
P
a
r
a
m
e
t
e
r
>
Figure 3-8
Syntax of a Response
Message Unit.
Then you send the following query to the
instrument:
:ROSCillator:SOURce?
SEND→
If there are multiple queries in a program
message, the instrument groups the multi-
ple response message units together in
one response message according to the
following syntax:
The instrument will return:
EXT
READ←
response in shortform and in capitals.
Program and Response Messages 3-9
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Introduction to SCPI
n Example:
Command Tree
INPut:EVENt:HYSTeresis
SEND→
Command Trees like the one below are
used to document the SCPI command set
in this manual. The keyword (mnemonic)
on the root level of the command tree is
the name of the subsystem. The follow-
ing example illustrates the Command
Tree of the INPut1 subsystem.
Where: INPut is the root node and HYSTer-
esis is the leaf node.
Each colon in the command header
moves the current path down one level
from the root in the command tree. Once
you reach the leaf node level in the tree,
you can add several leaf nodes without
having to repeat the path from the root
level.
<
H
E
A
D
E
R
>
P
a
r
a
m
e
t
e
r
s
:
I
N
P
u
t
[
1
]
Just follow the rules below:
I
8
<
<
N
u
m
e
r
i
c
v
a
l
u
e
>
|
M
A
X
|
M
N
:
I
M
P
e
d
a
n
c
e
:
F
I
L
T
e
r
– Always give the full header path, from the
root, for the first command in a new pro-
gram message.
[
:
L
P
A
S
s
]
[
:
S
T
8
A
T
B
e
o
]
o
l
e
a
n
>
– For the following commands within the
same program message, omit the header
path and send only the leaf node (without
colon).
Figure 3-10 Example of an INPut
subsystem command
tree.
You can only do this if the header
path of the new leaf-node is the
same as that of the previous one. If
not, the full header path must be
given starting with a colon.
The keywords placed in square
+
brackets are optional nodes. This
means that you may omit them
from the program message.
+
Example:
Command header = Header path + leaf
node
INPUT1:FILTER:LPASS
:STATE8ON
SEND→
– Once you send the pmt (program message
terminator), the first command in a new
program message must start from the root.
is the same as
INPUT:FILTER8ON
SEND→
n Example:
Moving down the Command
Tree
INPut:EVENt:HYSTeresis
MIN;LEVel80.5
SEND→
The command tree shows the paths you
should use for the command syntax. A
single command header begins from the
root level downward to the ‘leaf nodes’
of the command tree. (Leaf nodes are the
last keywords in the command header,
before the parameters.)
3-10 Command Tree
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Introduction to SCPI
The instrument always allows MINimum
and MAXimum as a data element in com-
mands, where the parameter is a numeric
value. MIN and MAX values of a param-
eter can always be queried.
This is the command where:
INPut:EVENt is the header path and
:HYSTeresis is the first leaf-node and
LEVel is the second leaf node because
LEVel is also a leaf-node under the
header path INPut:EVENt.
Example:
There is no colon before LEVel!
INP:LEV?8MAX
SEND→
+
This query returns the maximum range
value.
Parameters
n Suffixes
You can use suffixes to express a unit or
multiplier that is associated with the deci-
mal numeric data. Valid suffixes are s
(seconds), ms (milliseconds), mohm
(megaohm), kHz (kilohertz), mV (milli-
volt).
Numeric Data
Decimal data are printed as numerical
values throughout this manual. Numeric
values may contain both a decimal point
and an exponent (base 10).
These numerals are often represented as
NRf (NR = NumeRic, f = flexible) format.
Example:
:SENS:ACQ:APER8100ms
SEND→
n Keywords
Where: ms is the suffix for the numeric
value 100.
In addition to entering decimal data as
numeric values, several keywords can ex-
ist as special forms of numeric data, such
as MINimum, MAXimum, DEFault,
STEP, UP, DOWN, NAN (Not A Num-
ber), INFinity, NINF (Negative INFi-
nity). The Command Reference chapters
explicitly specify which keywords are al-
lowed by a particular command. Valid
keywords for the CNT-8X counters are
MAXimum and MINimum.
Notice that you may also send ms as MS
or mS. MS does still mean milliseconds,
not Mega Siemens!
Response messages do not have suffixes.
The returned value is always sent using
standard units such as V, S, Hz, unless
you explicitly specify a default unit by a
FORMat command.
Boolean Data
MINimum
A Boolean parameter specifies a single
binary condition which is either true or
false.
This keyword sets a parameter to its min-
imum value.
MAXimum
Boolean parameters can be one of the fol-
lowing:
This keyword sets a parameter to its max-
imum value.
– ON or 1 means condition true.
– OFF or 0 means condition false.
Parameters 3-11
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Introduction to SCPI
n Example
Other Data Types
SEND→ :SYST:TOUT8ON or
:SYST:TOUT81
Other data types that can be used for pa-
rameters are the following:
This switches timeout monitoring on.
A query, for instance :SYSTem:TOUT?,
will return 1 or 0; never ON or OFF.
– String data: Always enclosed between sin-
gle or double quotes, for example
“This is a string” or ‘This is a string.’
– Character data: For this data type, the same
rules apply as for the command header
mnemonics. For example: POSitive, NEG-
ative, EITHer.
Expression Data
You must enclose expression program
data in parenthesis (). Three possibilities
of expression data are as follows:
– Non-decimal data: For instance, #H3A for hexa
decimal data.
– <numeric expression data>
<parameter list>
– Block data: Used to transfer any 8-bit
coded data. This data starts with a pream-
ble that contains information about the
length of the parameter.
– <channel list>
An example of <numeric expression data> is:
(X – 10.7E6) This subtracts a 10.7 MHz
intermediate frequency from the mea-
sured result.
Example:
#218INP:IMP850;SENS810
An example of <parameter list> is: (5,0.02)
This is a list of two parameters; the
first one is 5 and the second one 0.02.
An example of <channel list> is: (@3),(@1)
This specifies channel 3 as the main
channel and channel 1 as the second
channel.
Summary
H
s
d
c
e
a
d
e
r
s
e
p
a
r
a
t
o
r
S
s
p
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i
c
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l
o
n
e
p
a
r
a
t
e
s
t
S
q
s
h
i
e
n
g
l
e
o
r
d
o
u
b
l
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A
m
t
i
q
u
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s
t
i
o
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e
p
a
r
a
t
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s
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a
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a
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s
p
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a
s
t
r
i
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g
s
r
e
q
u
e
s
t
e
d
[
:
S
E
N
S
]
:
F
U
N
C
"
F
R
E
Q
:
R
A
T
3
,
1
"
;
:
C
A
L
C
:
S
s
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f
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a
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s
f
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l
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N
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w
l
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p
a
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a
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s
f
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s
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p
o
a
w
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s
a
a
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i
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d
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a
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a
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3-12 Parameters
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Introduction to SCPI
within the language (like BASIC) we rec-
ommend that you use block data instead,
and use single quotes as string identifiers
within the macro.
Macros
A macro is a single command, that repre-
sents one or several other commands, de-
pending on your definition. You can
define 25 macros of 40 characters in the
counter. One macro can address other
macros, but you cannot call a macro from
within itself (recursion). You can use
variable parameters that modify the
macro.
When using string data for the
commands in a macro, remem-
ber to use a different type of
+
string data identifiers for strings
within the macro. If the macro
should for instance set the input
slope to positive and select the
period function, you must type:
Use macros to do the following:
“:Inp:slope8pos;:Func8’PER81’”
– Provide a shorthand for complex com-
mands.
or
‘:Inp:slope8pos;:Func8"PER81"’
– Cut down on bus traffic.
Define Macro Command
Macro Names
*DMC assigns a sequence of commands
to a macro label. Later when you use the
macro label as a command, the counter
will execute the sequence of commands.
You can use both commands and queries
as macro labels. The label cannot be the
same as common commands or queries.
If a macro label is the same as a CNT-8X
command, the counter will execute the
macro when macros are enabled
Use the following syntax:
*DMC <macro-label>, <commands>
(*EMC81) and it will execute the
CNT-8X command when macros are dis-
abled (*EMC80).
n Simple Macros
Example:
*DMC8‘MyInputSetting’
#255:INP:IMP850;HYST81
;LEV80.55;:INP:HYST:AUTO
80;
SEND→
Data Types within Macros
The commands to be performed by the
macro can be sent both as block and
string data.
This
example
defines
a
macro
MyInputSetting, which sets the impedance
to 50 Ω, sets the sensitivity to 1V, the
trigger level to +0.55V, and switches off
auto sensitivity and auto trigger level.
String data is the easiest to use since you
don’t have to count the number of charac-
ters in the macro. However, there are
some things you must keep in mind:
Both double quote (“) and single quote (‘)
can be used to identify the string data. If
you use a controller language that uses
double quotation marks to define strings
Macros 3-13
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Introduction to SCPI
n Macros with Arguments
Enabling and Disabling
Macros
You can pass arguments (variable param-
eters) with the macro. Insert a dollar sign
($) followed by a single digit in the range
1 to 9 where you want to insert the pa-
rameter. See the example below.
n *EMC Enable Macro Command
When you want to execute a CNT-8X
command or query with the same name
as a defined macro, you need to disable
macro execution. Disabling macros does
not delete stored macros; it just hides
them from execution.
When a macro with defined arguments is
used, the first argument sent will replace
any occurrence of $1 in the definition; the
second argument will replace $2, etc.
Disabling: *EMC80 disables all macros.
Enabling: *EMC81
Example:
*DMC8‘AUTO’,#247
:INP:HYST:AUTO8$1;
:INP:IMP8$2
SEND→
n *EMC? Enable Macro Query
Use this query to determine if macros are
enabled.
This example defines a macro AUTO,
which takes two arguments, i.e., auto
«ON|OFF|ONCE» ($1) and impedance
«50|1E6» ($2) .
Response:
1
0
macros are enabled
macros are disabled
AUTO8OFF,50
SEND→
Switches off both auto sensitivity and
auto trigger level and sets the input im-
pedance to 50Ω.
How to Execute a Macro
Macros are disabled after *RST, so to be
sure, start by enabling macros with
*EMC 1. Now macros can be executed
by using the macro labels as commands.
Deleting Macros
Use the *PMC (purge macro) command
to delete all macros defined with the
*DMC command. This removes all
macro labels and sequences from the
memory. To delete only one macro in the
n Example:
*DMC8‘LIMITMON’,’
:CALC:STAT8ON;
:CALC:LIM:STAT8ON;
:CALC:LIM:LOW:DATA
$1;STAT8ON;
SEND→
memory,
use
the
:MEMory:DE-
Lete:MACRo command.
:CALC:LIM:UPP:DATA
$2;STAT8ON’
You cannot overwrite a macro;
you must delete it before you can
use the same name for a new
macro.
*EMC81
SEND→
+
Now sending the command
LIMITMON81E6,1.1E6
SEND→
will switch on the limit monitoring to
alarm between the limits 1 MHz and
1.1 MHz.
3-14 Macros
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Introduction to SCPI
n *LMC? Learn Macro Query
Retrieve a Macro
This query gives a response containing
the labels of all the macros stored in the
Timer/Counter.
n *GMC? Get Macro Contents
Query
This query gives a response containing
the definition of the macro you specified
when sending the query.
Example:
*LMC?
SEND→
READ←
“MYINPSETTING”,"LIMITMON
"
Example using the above defined
macro:
Now there are two macros in memory,
and they have the following labels:
“MYINPSETTING” and “LIMITMON”.
*GMC?8‘LIMITMON’
#292:CALC:STAT
ON;:CALC:LIM:STAT ON;
:CALC:LIM:LOW:DATA
$1;STAT8ON;
SEND→
READ←
:CALC:LIM:UPP:DATA
$2;STAT8ON’
Macros 3-15
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Introduction to SCPI
You can select some conditions in the
counter that should be reported in the Sta-
tus Byte Register. You can also select if
some bits in the Status Byte should gen-
erate a Service Request (SRQ).
Status Reporting
System
Introduction
(An SRQ is the instrument’s way to call
the controller for help.)
Status reporting is a method to let the
controller know what the counter is do-
ing. You can ask the counter what status
it is in whenever you want to know.
Read more about the Status Subsystem in
Chapter 6.
S
t
a
n
d
a
r
d
E
v
e
n
t
R
e
g
i
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B
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Figure 3-11 CNT-8X Status register structure.
3-16 Status Reporting System
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Introduction to SCPI
0, “No error”
Error Reporting
When errors occur and you do not read
these errors, the Error Queue may over-
flow. Then the instrument will overwrite
the last error in the queue with the fol-
lowing:
The counter will place a detected error in
its Error Queue. This queue is a FIFO
(First-In First-Out) buffer. When you
read the queue, the first error will come
out first, the last error last.
–350, “Queue overflow”
If the queue overflows, an overflow mes-
sage is placed last in the queue, and fur-
ther errors are thrown away until there is
room in the queue again.
If more errors occur, they will be dis-
carded.
n Standardized Error Numbers
n Detecting Errors in the Queue
The instrument reports four classes of
standardized errors in the Standard Event
Status and in the Error/Event Queue as
shown in the following table:
Bit 2 in the Status Byte Register shows if
the instrument has detected errors. It is
also possible to enable this bit for Service
Request on the GPIB. This can then inter-
rupt the GPIB controller program when
an error occurs.
Error Class Range of
Error Num-
bers
Standard
Event
Register
n Read the Error/Event Queue
Command
–100 to
bit 5 - CME
bit 4 - EXE
bit 3 - DDE
Error
This is done with the :SYSTem:ERRor?
query.
–199
Execution
–200 to
Error
Example:
–299
:SYSTem:ERRor?
SEND→
Device- spe-
–300 to
–100,8“Command8Error”
READ←
cific Error
–399
+100 to
+32767
The query returns the error number fol-
lowed by the error description.
Query Error
–400 to
–499
Further description of all error
numbers can be found in the Er-
ror Messages chapter
bit 2 -QYE
+
n Command Error
If more than one error occurred, the query
will return the error that occurred first.
When you read an error you will also re-
move it from the queue. You can read the
next error by repeating the query. When
you have read all errors the queue is
empty, and the :SYSTem:ERRor? query
will return:
This error shows that the instrument de-
tected a syntax error.
Error Reporting 3-17
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Introduction to SCPI
n Execution Error
This error shows that the instrument has
received a valid program message which
it cannot execute because of some device
specific conditions.
n Device-specific Error
This error shows that the instrument
could not properly complete some device
specific operations.
n Query Error
This error will occur when the Message
Exchange Protocol is violated, for exam-
ple, when you send a query to the instru-
ment and then send a new command
without first reading the response data
from the previous query. Also, trying to
read data from the instrument without
first sending a query to the instrument
will cause this error.
3-18 Error Reporting
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Introduction to SCPI
The device-clear commands will not do
the following:
Initialization and
Resetting
– Change the instrument settings or stored
data in the instrument.
– Interrupt or affect any device operation in
progress.
Reset Strategy
There are three levels of initialization:
– Change the status byte register other than
clearing the MAV bit as a result of clearing
the output queue.
– Bus initialization
– Message exchange initialization
– Device initialization
Many older IEEE-instruments,
that are not IEEE-488.2 compati-
ble returned to the power-on de-
fault settings when receiving a
device-clear command.
IEEE-488.2 does not allow this.
+
n Bus Initialization
This is the first level of initialization. The
controller program should start with this
which initializes the IEEE-interfaces of
all connected instruments. It puts the
complete system into remote enable
(REN-line active) and the controller
sends the interface clear (IFC) command.
The command or the command sequence
for this initialization is controller and lan-
guage dependent. Refer to the user man-
ual of the system controller in use.
When to use a Device-clear Command
The command is useful to escape from
erroneous conditions without having to
alter the current settings of the instru-
ment. The instrument will then discard
pending commands and will clear re-
sponses from the output queue. For ex-
ample; suppose you are using the Counter
in an automated test equipment system
where the controller program returns to
its main loop on any error condition in
the system or the tested unit. To ensure
that no unread query response remains in
the output queue and that no unparsed
message is in the input buffer, it is wise
to use device-clear. (Such remaining re-
sponses and commands could influence
later commands and queries.)
n Message Exchange Initialization
Device clear is the second level of initial-
ization. It initializes the bus message ex-
change, but does not affect the device
functions.
Device clear can be signaled either with
DCL to all instruments or SDC (Selective
device-clear) only to the addressed instru-
ments. The instrument action on receiv-
ing DCL and SDC is identical, they will
do the following:
n Device Initialization
The third level of initialization is on the
device level. This means that it concerns
only the addressed instruments.
– Clear the input buffer.
– Clear the output queue.
– Reset the parser.
– Clear any pending commands.
Initialization and Resetting 3-19
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Introduction to SCPI
The *RST Command
Use this command to reset a device. It
initializes the device-specific functions in
the Counter.
The following happens when you use the
*RST command:
– You set the Counter-specific functions to a
known default state. The *RST condition
for each command is given in the com-
mand reference chapters.
– You disable macros.
– You set the counter in an idle state (outputs
are disabled), so that it can start new oper-
ations.
The *CLS Command
Use this command to clear the status data
structures. See ‘Status Reporting system’
in this chapter.
The following happens when you use the
*CLS command:
– The instrument clears all event registers
summarized in the status byte register.
– It empties all queues, which are summa-
rized in the status byte register, except the
output queue, which is summarized in the
MAV bit.
3-20 Initialization and Resetting
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Programming Examples
Introduction
Each program example in this chapter is
written for IBM-PC compatible comput-
ers equipped with the National Instru-
ments PC-IIA. In addition to that, many
of the examples are written in both
‘GW-BASIC’ and ‘C’.
Even if you do not have these interface
board or use these computer languages,
look at the examples anyway. They give
you a good insight on how to program the
instrument efficiently.
To be able to run these programs
without modification, the address
+
Example 1. Limit Testing
of your counter must be set to 10.
Example 2. REAL Data Format
Example 3. Frequency Profiling
Example 4. Fast Sampling
Example 5. Status Reporting
Example 6. Statistics, this example is only for
PM6680B and PM6681
4-2 Introduction
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Programming Examples
GW-Basic for National
Instruments PC-IIA
Setting up the interface
All these programs start with a declaration containing three lines of setup information
for the interface. This declaration must be merged with the programs prior to running
them. The declaration is printed below, but it is also available as a file on the diskettes
delivered with your interface. The file name is DECL.BAS.
20 CLEAR ,60000! : IBINIT1=60000! : IBINIT2=IBINIT1+3 : BLOAD
“bib.m”,IBINIT1
30 CALL
IBINIT1(IBFIND,IBTRG,IBCLR,IBPCT,IBSIC,IBLOC,IBPPC,IBBNA,
IBONL,IBRSC,IBSRE,IBRSV,IBPAD,IBSAD,IBIST,IBDMA,IBEOS,IBTMO,IBEO
T, IBRDF,IBWRTF,IBTRAP,IBDEV,IBLN)
40 CALL
IBINIT2(IBGTS,IBCAC,IBWAIT,IBPOKE,IBWRT,IBWRTA,IBCMD,IBCMDA,
IBRD,IBRDA,IBSTOP,IBRPP,IBRSP,IBDIAG,IBXTRC,IBRDI,IBWRTI,IBRDIA,
IBWRTIA,IBSTA%,IBERR%,IBCNT%)
GW-Basic for National Instruments PC-IIA, Setting Up the Interface 4-3
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Programming Examples
1. Limit Testing
This program uses limit testing to check that the frequency is above a preset value.
50 CNTNAME$ = “DEV10"
60 CALL IBFIND (CNTNAME$, CNT%)
70 ‘
80 ‘
90 ‘ —— Set continuous frequency measurement ——
100 WRT$ = “*RST; *CLS; :FUNC ‘FREQ 1’; :INIT:CONT ON”
110 CALL IBWRT (CNT%, WRT$)
120 ‘
130 ‘ —— Enable limit monitoring, limit 1 MHz ——
140 WRT$ = “:CALC:LIM ON; LIM:UPP 1E6; UPP:STATE ON”
150 CALL IBWRT (CNT%, WRT$)
160 WRT$ = “:STAT:DREG0:ENAB 2; *SRE 1"
170 CALL IBWRT (CNT%, WRT$)
180 ‘
190 ‘ —— Wait until the limit is passed ——
200 PRINT “Waiting for limit to be passed”
210 MASK% = &H800
220 CALL IBWAIT (CNT%, MASK%)
230 ‘
240 ‘ —— Read status and device status register ——
250 CALL IBRSP (CNT%, SPR%)
260 ‘
270 ‘ —— Read frequency ——
280 WRT$ = “READ?”
290 CALL IBWRT (CNT%, WRT$)
300 MSG$ = SPACE$(255)
310 CALL IBRD (CNT%, MSG$)
320 PRINT “Frequency = ”; LEFT$(MSG$, IBCNT%)
330 WRT$ = “:STAT:DREG0:EVEN?”
340 CALL IBWRT (CNT%, WRT$)
350 MSG$ = SPACE$(255)
360 CALL IBRD (CNT%, MSG$)
370 ‘
380 ‘ —— Disable continuous measurement ——
390 WRT$ = “:INIT:CONT OFF”
400 CALL IBWRT (CNT%, WRT$)
410 END
4-4 GW-Basic for National Instruments PC-IIA, Setting Up the Interface
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Programming Examples
3. Frequency Profiling
Frequency profiling visualizes frequency variations for a certain time. This program
gives an output file called:
PROFILE.DAT. If this file is imported to a spreadsheet program, for instance Excel,
you can create a graph like the one in the figure below.
Figure 4-1
This figure is the results of frequency profiling on a
sweep generator.
50 ‘
60 OPEN “O”, 1, “PROFILE.DAT”
70 CNTNAME$ = “DEV10"
80 CALL IBFIND (CNTNAME$, CNT%)
90 ‘
100 ‘
110 ‘ —— Enable arming, etc. ——
120 WRT$ = “:TRIG:COUN 1; :ARM:COUN 1; SOUR EXT4"
130 CALL IBWRT(CNT%, WRT$)
140 WRT$ = “:INP:LEV:AUTO ONCE
150 CALL IBWRT(CNT%, WRT$)
160 WRT$ = “:DISP:ENAB OFF; :ACQ:APER 1E-6"
170 CALL IBWRT(CNT%, WRT$)
180 ‘
190 ARMDELAY = .0000002
GW-Basic for National Instruments PC-IIA, Setting Up the Interface 4-5
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Programming Examples
200 ‘
210 ‘ ==== CAPTURE PROFILE =====
220 ‘
230 PRINT “Profiling”
240 ‘
250 FOR I=0 TO 999
260
270
280
290
300
310
320
330
340
350
360
370
‘ —— Set arming delay time --
WRT$ = “:ARM:DEL” + STR$(ARMDELAY)
CALL IBWRT(CNT%, WRT$)
‘
‘ —— Measure and read result --
WRT$ = “READ?”
CALL IBWRT(CNT%, WRT$)
MSG$ = SPACE$(255)
CALL IBRD(CNT%, MSG$)
‘
‘ —— Write arming delay time and result to file --
PRINT#1, STR$(ARMDELAY), LEFT$(MSG$, INSTR(MSG$,
CHR$(10)))
380
390
400
‘
‘ —— Increase arming delay --
ARMDELAY = ARMDELAY + .0000001
410 NEXT I
420 ‘
430 WRT$ = “:DISP:ENAB ON”
440 CALL IBWRT(CNT%, WRT$)
450 ‘
460 CLOSE 1
470 END
4-6 GW-Basic for National Instruments PC-IIA, Setting Up the Interface
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Programming Examples
4. Fast Sampling
This program makes a quick array measurement and stores the results in the internal
memory of the counter. Then it writes the results to a file called MEAS.DAT. The
measurement results as a function of the samples can be visualized in a spreadsheet
program such as Excel.
50 ‘
60 OPEN “O”, 1, “MEAS.DAT”
70 CNTNAME$ = “DEV10"
80 CALL IBFIND (CNTNAME$, CNT%)
90 ‘
100 ‘
110 ‘ —— Clear status ——
120 WRT$ = “*CLS”
130 CALL IBWRT(CNT%, WRT$)
140 ‘
150 ‘ —— Enable 1000 measurement with maximum speed ——
160 WRT$ = “:TRIG:COUN 1000; :ARM:COUN 1"
170 CALL IBWRT (CNT%, WRT$)
180 WRT$ = “:INP:LEV:AUTO ONCE; :CAL:INT:AUTO OFF”
190 CALL IBWRT (CNT%, WRT$)
200 WRT$ = “:DISP:ENAB OFF; :INT:FORM PACKED”
210 CALL IBWRT (CNT%, WRT$)
220 WRT$ = “:ACQ:APER MIN; :AVER:STAT OFF”
230 CALL IBWRT (CNT%, WRT$)
240 ‘
250 ‘ —— Enable SRQ on operation complete ——
260 WRT$ = “*ESE 1; *SRE 32"
270 CALL IBWRT (CNT%, WRT$)
280 ‘
290 ‘ —— Start measurement ——
300 PRINT “Measuring”
310 WRT$ = “INIT; *OPC”
320 CALL IBWRT (CNT%, WRT$)
330 ‘
340 ‘ —— Wait for operation complete ——
350 MASK = &H800
360 CALL IBWAIT (CNT%, MASK)
370 ‘
380 ‘ —— Read status and event status register ——
390 CALL IBRSP (CNT%, SPR%)
400 WRT$ = “*ESR?”
410 CALL IBWRT (CNT%, WRT$)
420 MSG$ = SPACE$(255)
430 CALL IBRD (CNT%, MSG$)
GW-Basic for National Instruments PC-IIA, Setting Up the Interface 4-7
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Programming Examples
440 ‘
450 PRINT “Fetching result”
460 ‘
470 FOR I=0 TO 999
480
490
500
510
520
530
540
550
‘ —— Fetch one result ——
WRT$ = “FETCH?”
CALL IBWRT (CNT%, WRT$)
MSG$ = SPACE$(255)
CALL IBRD (CNT%, MSG$)
‘
‘ —— Write result to file ——
PRINT#1, I, LEFT$(MSG$, INSTR(MSG$, CHR$(10)))
560 NEXT I
570 ‘
580 WRT$ = “:DISP:ENAB ON”
590 CALL IBWRT(CNT%, WRT$)
600 ‘
610 CLOSE 1
620 END
4-8 GW-Basic for National Instruments PC-IIA, Setting Up the Interface
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Programming Examples
5. Status Reporting
This program sets up the status reporting for Service Request on ‘Message Available’
and ‘Command’, ‘Execution’, or Query’ errors.
The program reads a command from the controller keyboard and sends it to the coun-
ter, then it checks the status byte using Serial Poll. It determines the reason for Service
Request, and reads query responses and error messages.
50 CNTNAME$ = “DEV10"
60 CALL IBFIND (CNTNAME$, CNT%)
70 ‘
80 ‘
90 ‘ —— CLEAR STATUS ——
100 WRT$ = “*cls”
110 CALL IBWRT (CNT%, WRT$)
120 ‘
130 ‘ —— SET EVENT STATUS ENABLE ——
140 ‘ Enable Command Error, Execution Error and Query Error
150 WRT$ = “*ese 52"
160 CALL IBWRT (CNT%, WRT$)
170 ‘
180 ‘ —— SET SERVICE REQUEST ENABLE ——
190 ‘ Enable Service Request on Event Status and Message
Available
200 WRT$ = “*sre 48"
210 CALL IBWRT (CNT%, WRT$)
220 ‘
230 ‘ ======== MAIN LOOP =======================================
240 WHILE 1
250
260
270
280
290
300
310
320
330
340
350
360
370
380
390
400
‘
‘ —— ENTER COMMAND STRING AND SEND TO COUNTER ——
LINE INPUT “Enter command string (<CR> to end):”, CMD$
IF CMD$ = “” GOTO 760
CMD$ = CMD$
CALL IBWRT (CNT%, CMD$)
‘ WAIT for execution
FOR I=1 TO 1000
CALL IBRSP (CNT%, SPR%)
IF SPR% AND 16 THEN GOTO 380
NEXT I
‘
‘ —— READ STATUS BYTE ——
IF SPR% <> 0 THEN PRINT “Status byte = ”; SPR%
ELSE GOTO 750
‘
GW-Basic for National Instruments PC-IIA, Setting Up the Interface 4-9
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Programming Examples
410
420
430
440
450
460
470
‘ —— CHECK MESSAGE AVAILABLE BIT ——
WHILE SPR% AND 16
PRINT “ Message available bit set”
MSG$ = SPACE$(255)
CALL IBRD (CNT%, MSG$)
LFPOS = INSTR(MSG$, CHR$(10))
IF LFPOS <> 0 THEN PRINT “Response = ” LEFT$(MSG$,
LFPOS)
480
490
500
510
520
530
540
550
560
570
580
590
600
610
620
630
640
650
660
670
680
690
700
710
720
730
740
750 WEND
IF LFPOS = 0 THEN PRINT “Response = ”; MSG$
CALL IBRSP (CNT%, SPR%)
WEND
‘
‘ —— CHECK EVENT STATUS BIT ——
IF NOT SPR% AND 32 GOTO 750
PRINT “ Event status bit set”
WRT$ = “*esr?”
CALL IBWRT (CNT%, WRT$)
ESR$ = SPACE$(255)
CALL IBRSP (CNT%, SPR%)
CALL IBRD (CNT%, ESR$)
ESR% = VAL(ESR$)
IF ESR% AND 32 THEN PRINT “
IF ESR% AND 16 THEN PRINT “
IF ESR% AND 4 THEN PRINT “
‘
Command error”
Execution error”
Query error”
‘ —— READ ERROR MESSAGES ——
WRT$ = “syst:err?”
ERRMESS$ = SPACE$(255)
CALL IBWRT (CNT%, WRT$)
CALL IBRD (CNT%, ERRMESS$)
WHILE NOT INSTR(ERRMESS$, “No error”) <> 0
PRINT LEFT$(ERRMESS$, INSTR(ERRMESS$, CHR$(10)))
CALL IBWRT (CNT%, WRT$)
CALL IBRD (CNT%, ERRMESS$)
WEND
760 PRINT “PROGRAM TERMINATED”
770 END
4-10 GW-Basic for National Instruments PC-IIA, Setting Up the Interface
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Programming Examples
6. Statistics
(Only for PM6680B and PM6681)
In this example, the counter makes 10000 measurements and uses the statistical func-
tions to determine MAX, MIN, MEAN, and Standard Deviation. All four results are
sent to the controller.
50 CNTNAME$ = “DEV10"
60 CALL IBFIND (CNTNAME$, CNT%)
70 ‘
80 ‘
90 WRT$ = “*RST; *CLS; *SRE 16; :FUNC ‘Freq 1’; :ACQ:APER MIN”
100 CALL IBWRT (CNT%, WRT$)
110 WRT$ = “:INP:LEV:AUTO Off”
120 CALL IBWRT (CNT%, WRT$)
130 ‘
140 ‘ —— Enable statistics on 10000 measurements ——
150 WRT$ = “:CALC:AVER:STAT ON; COUN 10000"
160 CALL IBWRT (CNT%, WRT$)
170 ‘
180 ‘ ==== Start measurement ====
190 WRT$ = “:Init; *OPC?”
200 CALL IBWRT (CNT%, WRT$)
210 ‘
220 ‘ —— Wait for operation complete (MAV) ——
230 PRINT “WAITING FOR MEASUREMENT TO GET READY”
240 MASK% = &H800
250 CALL IBWAIT (CNT%, MASK%)
260 ‘
270 ‘ —— Read status and response ——
280 CALL IBRSP (CNT%, SPR%)
290 MSG$ = SPACE$(255)
300 CALL IBRD (CNT%, MSG$)
310 ‘
320 ‘ —— Maximum ——
330 WRT$ = “:CALC:AVER:TYPE MAX; :CALC:IMM?”
340 CALL IBWRT (CNT%, WRT$)
350 MSG$ = SPACE$(255)
360 CALL IBRD (CNT%, MSG$)
370 PRINT “MAXIMUM = ”; LEFT$(MSG$, IBCNT%)
380 ‘
390 ‘ —— Minimum ——
400 WRT$ = “:CALC:AVER:TYPE MIN; :CALC:IMM?”
410 CALL IBWRT (CNT%, WRT$)
420 MSG$ = SPACE$(255)
GW-Basic for National Instruments PC-IIA, Setting Up the Interface 4-11
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Programming Examples
430 CALL IBRD (CNT%, MSG$)
440 PRINT “MINIMUM =”; LEFT$(MSG$, IBCNT%)
450 ‘
460 ‘ —— Mean ——
470 WRT$ = “:CALC:AVER:TYPE MEAN; :CALC:IMM?”
480 CALL IBWRT (CNT%, WRT$)
490 MSG$ = SPACE$(255)
500 CALL IBRD (CNT%, MSG$)
510 PRINT “MEAN =”; LEFT$(MSG$, IBCNT%)
520 ‘
530 ‘ —— Standard deviation ——
540 WRT$ = “:CALC:AVER:TYPE SDEV; :CALC:IMM?”
550 CALL IBWRT (CNT%, WRT$)
560 MSG$ = SPACE$(255)
570 CALL IBRD (CNT%, MSG$)
580 PRINT “STANDARD DEVIATION =”; LEFT$(MSG$, IBCNT%)
590 END
4-12 GW-Basic for National Instruments PC-IIA, Setting Up the Interface
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Programming Examples
1. Limit Testing
This program uses limit testing to check that the frequency is above a preset value.
#include “decl.h”
#include <stdio.h>
#include <process.h>
main ()
{
int
char
Counter, Status, i;
InString[80];
Counter = ibfind(“DEV10");
/*Set continuous frequency measurement*/
ibwrt(Counter, “*RST; *CLS; :FUNC ‘Freq 1’; :INIT:CONT ON”,
41);
/*Enable limit monitoring, limit 1 MHz*/
ibwrt(Counter, “:CALC:LIM ON; LIM:UPP 1E6; UPP:STAT ON”, 38);
ibwrt(Counter, “:STAT:DREG0:ENAB 2; *SRE 1", 26);
/*Wait until the limit is passed*/
printf(“Waiting for limit to be passed\n”);
ibwait(Counter, RQS);
/**Read status and device status register**/
ibrsp(Counter, &Status);
ibwrt(Counter, “:STAT:DREG0:EVEN?”, 17);
ibrd(Counter, InString, 80);
/*Read frequency**/
ibwrt(Counter, “READ?”, 5);
ibrd(Counter, InString, 80);
InString[ibcnt] = ‘\0’;
printf(“Frequency = %s\n”, InString);
/*Disable continuous measurement*/
ibwrt(Counter, “:INIT:CONT OFF”, 14);
exit(0);
}
4-14 ‘C’ for National Instruments PC-IIA, Limit Testing
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Programming Examples
2. REAL Data Format
This program uses the REAL data format to speed up the measurement.
/* IEEE 488.2 binary real format follows the ‘little-endian’ format with the
most-significant byte first and the least-significant byte last. Intel processors use the
‘big-endian’ format, with the least-significant byte first, so we have to reverse the byte
order of the incoming block when running on a PC (Intel processor).
#include “decl.h”
#include <stdio.h>
#include <process.h>
#include <conio.h>
main ()
{
int
char
Counter, i;
InString[80];
DoubleFreq;
double
Counter = ibfind(“DEV10");
/*Make the counter output it’s result in real format*/
ibwrt(Counter, “:FORM REAL”, 10);
/*Make continuous measurements until a key is hit*/
do {
/*Make a measurement and read the result*/
ibwrt(Counter, “READ?”, 5);
ibrd(Counter, InString, 80);
/*Assign the bytes 3...10 of InString to DoubleFreq bytes
7...0.
The format of InString is #18******** , where “********”
represents the value.*/
for (i=0; i<8; i++)
((unsigned char *)&DoubleFreq)[7-i] = InString[3+i];
/*Print the result*/
printf(“%le\n”, DoubleFreq);
} while (!kbhit());
/*Restore ascii output format*/
ibwrt(Counter, “:FORM ASCII”, 11);
exit(0);
}
‘C’ for National Instruments PC-IIA, Real Data Format 4-15
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Programming Examples
3. Frequency Profiling
Frequency profiling visualizes frequency variations for a certain time. This program
gives an output file called:
PROFILE.DAT. If this file is imported to a spreadsheet program, such as Excel, you
can create a graph like the one in the figure below.
Figure 4-2
This figure is the results of frequency profiling on a
sweep generator.
#include “decl.h”
#include <stdio.h>
#include <process.h>
#include <string.h>
main ()
{
int
char
Counter, i;
ArmString[80],
InString[80];
double
FILE
ArmDelay;
*ofp;
if (ofp = fopen(“PROFILE.DAT”, “w”)) {
Counter = ibfind(“DEV10");
/*Enable arming, etc.*/
ibwrt(Counter, “:TRIG:COUN 1; :ARM:COUN 1", 25);
4-16 ‘C’ for National Instruments PC-IIA, Frequency Profiling
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Programming Examples
ibwrt(Counter, “:INP:LEV:AUTO ONCE”, 18);
ibwrt(Counter, “:DISP:ENAB OFF; :ACQ:APER 1E-6", 30);
ArmDelay=200e-9;
/*CAPTURE PROFILE*/
Printf(”Profiling”);
for (i=0; i<1000; i++) {
/*Set arming delay time*/
sprintf(ArmString, “:ARM:DEL %le”, ArmDelay);
ibwrt(Counter, ArmString, strlen(ArmString));
/*Measure and read result*/
ibwrt(Counter, “READ?”, 5);
ibrd(Counter, InString, 80);
InString[ibcnt] = ‘\0’;
/*Write arming delay time and result to file*/
fprintf(ofp, “%le, %s”, ArmDelay, InString);
/*Increase arming delay*/
ArmDelay += 100e-9;
}
ibwrt(Counter, “:DISP:ENAB ON”, 13);
/*Close file*/
Fclose(ofp);
} else
printf(“CANT OPEN FILE”);
exit(0);
}
4-17 ‘C’ for National Instruments PC-IIA, Frequency Profiling
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Programming Examples
4. Fast Sampling
This program makes a quick array measurement and stores the results in the internal
memory of the counter. Then it writes the results to a file called MEAS.DAT. The
measurement results as a function of the samples can be visualized in a spreadsheet
program, such as Excel.
#include “decl.h”
#include <stdio.h>
#include <process.h>
#include <string.h>
main ()
{
int
Counter, Status, i;
InString[80];
*ofp;
char
FILE
if (ofp = fopen(“MEAS.DAT”, “w”)) {
Counter = ibfind(“DEV10");
/*Clear status*/
ibwrt(Counter, “*CLS”, 4);
/*Enable 1000 measurement with maximum speed*/
ibwrt(Counter, “:TRIG:COUN 1000; :ARM:COUN 1", 28);
ibwrt(Counter, “:INP:LEV:AUTO ONCE; :CAL:INT:AUTO OFF”, 37);
ibwrt(Counter, “:DISP:ENAB OFF; :INT:FORM PACKED”, 32);
ibwrt(Counter, “:ACQ:APER MIN; :AVER:STAT OFF”, 32);
/**Enable SRQ on operation complete**/
ibwrt(Counter, “*ESE 1; *SRE 32", 15);
/*Start measurement*/
printf(“Measuring\n”);
ibwrt(Counter, “INIT; *OPC”, 10);
/*Wait for operation complete*/
ibwait(Counter, RQS);
/**Read status and event status register**/
ibrsp(Counter, &Status);
ibwrt(Counter, “*ESR?”, 5);
4-18 ‘C’ for National Instruments PC-IIA, Fast Sampling
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Programming Examples
ibrd(Counter, InString, 80);
printf(“Fetching result”);
for (i=0; i<1000; i++) {
/*Fetch one result*/
ibwrt(Counter, “FETCH?”, 6);
ibrd(Counter, InString, 80);
InString[ibcnt] = ‘\0’;
/*Write result to file*/
fprintf(ofp, “%d, %s”, i, InString);
}
ibwrt(Counter, “:DISP:ENAB ON”, 13);
/*Close file*/
Fclose(ofp);
} else
printf(“CANT OPEN FILE”);
exit(0);
}
‘C’ for National Instruments PC-IIA, Fast Sampliing 4-19
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Programming Examples
6. Statistics
(Only for PM6680B and PM6681)
In this example, the counter makes 10000 measurements and uses the statistical func-
tions to determine MAX, MIN, MEAN, and Standard Deviation. All four results are
sent to the controller.
#include “decl.h”
#include <stdio.h>
#include <process.h>
main ()
{
int
Counter, Status, i;
InString[80];
char
Counter = ibfind(“DEV10");
ibwrt(Counter, “*CLS; *SRE 16", 13);
ibwrt(Counter, “*RST; :FUNC ‘Freq 1’; :ACQ:APER MIN”, 38);
ibwrt(Counter, “:INP:LEV:AUTO OFF”, 17);
/*Enable statistics on 10000 measurements*/
ibwrt(Counter, “:CALC:AVER:STAT ON; COUN 10000", 30);
ibwrt(Counter, “:TRIG:COUN 10000", 16);
/*Start measurement*/
ibwrt(Counter, “:Init; *OPC?”, 12);
/*Wait for operation complete (MAV)*/
printf(“Waiting for measurement to get ready\n”);
ibwait(Counter, RQS);
/**Read status and response**/
ibrsp(Counter, &Status);
ibrd(Counter, InString, 80);
/*Read maximum value**/
ibwrt(Counter, “:CALC:AVER:TYPE MAX; :CALC:IMM?”, 31);
ibrd(Counter, InString, 80);
InString[ibcnt] = ‘\0’;
printf(“Maximum = %s\n”, InString);
4-20 ‘C’ for National Instruments PC-IIA, Statistics
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Programming Examples
/*Read minimum value*/
ibwrt(Counter, “:CALC:AVER:TYPE MIN; :CALC:IMM?”, 31);
ibrd(Counter, InString, 80);
InString[ibcnt] = ‘\0’;
printf(“Minimum = %s\n”, InString);
/*Read mean value*/
ibwrt(Counter, “:CALC:AVER:TYPE MEAN; :CALC:IMM?”, 32);
ibrd(Counter, InString, 80);
InString[ibcnt] = ‘\0’;
printf(“Mean = %s\n”, InString);
/*Read standard deviation value*/
ibwrt(Counter, “:CALC:AVER:TYPE SDEV; :CALC:IMM?”, 32);
ibrd(Counter, InString, 80);
InString[ibcnt] = ‘\0’;
printf(“Standard deviation = %s\n”, InString);
exit(0);
}
‘C’ for National Instruments PC-IIA, Statistics 4-21
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Instrument Model
An instrument may use a combination of
the above functions. The CNT-8X coun-
ters belong to the signal acquisition cate-
gory, and only that category is described
in this manual.
Introduction
The figure below shows how the instru-
ment functions are categorized. This in-
strument model is fully compatible with
the SCPI generalized instrument model.
fines where elements of the counter lan-
guage are assigned in the command
hierarchy. The major signal function ar-
eas are shown broken into blocks. Each
of these blocks are major command
sub-trees in the counter command lan-
guage.
The generalized SCPI instrument model,
contains three major instrument catego-
ries as shown in the following table:
Function Instrument Examples
type
Signal ac- Sense in- Voltmeter, Os-
quisition struments
The instrument model also shows how
measurement data and applied signals
flow through the instrument. The model
does not include the administrative data
flow associated with queries, commands,
performing calibrations etc.
cilloscope,
Counter
Signal
genera-
tion
Source in- Pulse genera-
struments
tor, Power sup-
ply
Signal
routing
Switch in-
struments
Scaners,(de)-m
ultiplexers
Inputs
A
Channels
1
DISPlay
2
3
4
B
C
E
GPIB
FORMat
Measurement Function
OUTPut
TRIGger
MEMory
Figure 5-1
CNT-8X Instrument model. Note that Input B (channel 2) is not avail-
able on PM6685.
5-2 Introduction
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Instrument Model
block. The INPut block includes cou-
pling, impedance, filtering etc.
Measurement
Function Block
n SENSe
The measurement function block converts
the input signals into an internal data for-
mat that is available for formatting into
GPIB bus data. The measurement func-
tion is divided into three different blocks:
INPut, SENSe and CALCulate. See
The SENSe block converts the signals
into internal data that can be processed by
the CALCulate block. The SENSe com-
mands control various characteristics of
the measurement and acquisition process.
These include: gate time, measurement
function, resolution, etc.
n INPut
n CALCulate
The INPut block performs all the signal
conditioning of the input signal before it
is converted into data by the SENSe
The CALCulate block performs all the
necessary calculations to get the required
data. These calculations include: calibra-
tion, statistics, mathematics, etc.
1
INPut1
INPut2
A
B
C
E
DISPlay
2
3
4
5
INPut4
GPIB
CALCulate
FORMat
SENSe
÷2
6
7
10MHz
clock
OUTPut
TRIGger
MEMory
Figure 5-2
CNT-8X Measurement model. Note that Input B ( channel 2 ) is not
available on PM6685
Measurement Function Block 5-3
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Instrument Model
n Synchronization
Other Subsystems
This subsystem can be used to synchro-
nize the measurements with the control-
ler.
In addition to the major functions (sub-
systems), there are several other subsys-
tems in the instrument model.
n SYSTem
The different blocks have the following
functions.
This subsystem controls some system pa-
rameters like timeout.
n CALibration
n TEST
This subsystem controls the calibration of
the interpolators used to increase the res-
olution of the CNT-8X counters.
This subsystem tests the hardware and
software of the counter and reports errors.
n TRIGger
n DISPlay
The trigger block provides the counter
with synchronization capability with ex-
ternal events. Commands in this block
control the trigger and arming functions
of the Timer/ Counter.
Commands in this subsystem control
what data is to be present on the display
and whether the display is on or off.
n FORMat
The FORMat block converts the internal
data representation to the data transferred
over the external GPIB interface. Com-
mands in this block control the data type
to be sent over the external interface.
Order of Execution
– All commands in CNT-8X counters are se-
quential, i.e., they are executed in the same
order as they are received.
n MEMory
The MEMory block holds macro and in-
strument state data inside the counter.
– If a new measurement command is re-
ceived when a measurement is already in
progress, the measurement in progress will
be aborted unless WAI is used before the
command.
n OUTPut
This subsystem controls the analog out-
put available in the CNT-8X counters.
n STATus
This subsystem can be used to get infor-
mation about what is happening in the in-
strument at the moment.
5-4 Other Subsystems
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Instrument Model
anything about the instrument you are us-
ing. See Figure 5-3.
MEASurement
Function
n MEASure?
This is the most simple command to use,
but it does not offer much flexibility. The
MEASure? query lets the counter config-
ure itself for an optimal measurement,
start the data acquisition, and return the
result.
In addition to the subsystems of the in-
strument model, which controls the in-
strument
functions,
SCPI
has
signal-oriented functions to obtain mea-
surement results. This group of MEASure
functions has a different level of compati-
bility and flexibility. The parameters used
with commands from the MEASure
group describe the signal you are going to
measure. This means that the MEASure
functions give compatibility between in-
struments, since you don’t need to know
n CONFigure; READ?
The CONFigure command makes the
counter choose an optimal setting for the
specified measurement. CONFigure
may cause any device setting to change.
1
A
B
C
E
INPut1
INPut2
DISPlay
2
3
4
5
GPIB
INPut4
SENSe
CALCulate
FORMat
OUTPut
FETch?
÷2
6
7
10MHz
clock
TRIGger
MEMory
READ?
CONFigure
MEASure?
Figure 5-3
CNT-8X Measurement Function
Note that Input B (channel 2) is not available on PM6685.
MEASurement Function 5-5
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Instrument Model
READ? starts the acquisition and returns
the result.
This sequence does the same as the MEA-
Sure command, but now it is possible to
insert commands between CONFigure
and READ? to adjust the setting of a par-
ticular function (called fine tuning). For
instance, you can set an input attenuator
at a required value.
n CONFigure; INITiate;FETCh?
The READ? command can be divided
into the INITiate command, which starts
the measurement, and the FETCh? com-
mand, which requests the instrument to
return the measuring results to the con-
troller.
Versatility of Measurement Com-
mands
MEASure?
Simple to use,, few
additional possibili-
ties.
CONFigure
READ?
Somewhat more
difficult,, but some
extra possibilities.
CONFigure
INITiate
FETCh?
Most difficult to
use,, but many ex-
tra features.
5-6 MEASurement Function
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Using the Subsystems
Introduction
Although SCPI is intended to be self ex-
not explain each and every command,
planatory, we feel that some hints and but only those for which we believe extra
tips on how to use the different subsys- explanations are necessary.
tems may be useful. This chapter does
6-2
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Using the Subsystems
Calculate Subsystem
The calculate subsystem processes the n Limit Monitoring
measuring results. Here you can recalcu-
Limit monitoring makes it is possible to
late the result using mathematics, make
statistics (not PM6685) and set upper and
lower limits for the measuing result that
the counter itself monitors and alerts you
when the limits are exceeded.
get a service request when the measure-
ment value falls below a lower limit or
rises above an upper limit. Two status
bits are defined to support limit monitor-
ing. One is set when the results are
greater than the UPPer limit, the other is
set when the result is less than the
LOWer limit. The bits are enabled using
the standard *SRE command and
:STAT:DREG0:ENAB. Using both these
bits, it is possible to get a service request
when a value passes out of a band (
UPPer is set at the upper band border and
LOWer at the lower border) OR when a
n Mathematics
The mathematic functions are the same as
on the front panel.
n Statistics
The PM6680B and PM6681 can calculate
and display the MIN, MAX, MEAN and
standard deviation of a given number of
samples. The statistic functions are the
same as on the front panel.
measurement value enters
a
band
(LOWer set at the upper band border and
UPPer set at the lower border).
Turning the limit monitoring calculations
on/off will not influence the status regis-
ter mask bits which determine whether or
not a service request will be generated
when a limit is reached. Note that the cal-
culate subsystem is automatically enabled
when limit monitoring is switched on.
This means that other enabled calculate
sub-blocks are indirectly switched on.
Calculate Subsystem 6-3
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Using the Subsystems
Calibration Subsystem
The interpolators used to increase the res- n PM6681
olution of the measurement result in the
In PM6681, the interpolators are factory
counter must be calibrated to maintain the
highest possible accuracy of the counter.
calibrated. Calibration must be performed
only after repair and can be performed at
your local Service centers.
The calibration method of the PM6681
differs from the method used in
PM6680B and PM6685.
If the calibration is lost for any reason,
the counter will show ZCAL. LOSTZ.
n PM6680B, PM6685
By pressing PRESET you can bypass this
message and use the counter anyway,
however you must press the front panel
key. No bus command takes you past this
error message.
The intepolators are automatically cali-
brated before each measurement. This
procedure takes only a fraction of a sec-
ond, but to increase speed, you can turn
off the auto calibration.
This is so that you cannot bypass the
message by mistake, and run a test sys-
tem without a calibrated instrument.
6-4 Calibration Subsystem
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Using the Subsystems
Configure Function
The CONFigure command sets up the change any parameters before making the
counter to make the same measurements measurement.
as the MEASure query, but without initi-
Read more about Configure under MEA-
ating the measurement and fetching the
Sure.
result. Use configure when you want to
Configure Function 6-5
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Using the Subsystems
Format Subsystem
Time Stamp
Readout Format
The first will be the measured value, and
the next one will be the timestamp value,
given in seconds in the NR2 format
ddd.ddddddddd (12 digits).
It is not trivial to decide how time
stamped measurements are to be pre-
sented on the bus. If the ‘ADIF’ format
defined by SCPI is adopted, it should be
adopted for all data readout, and switched
on and off by the already standardized
:FORMat:DINTerchange command. This
format covers the appropriate readout for-
mat for time stamped measurements well,
so when it is selected as output format,
there is not any problem. But the user
may still decide not to use the ADIF for-
mat, so we need a solution to the readout
problem whether or not we decide to im-
plement ADIF. The chosen one is as fol-
lows:
In :FORMat ASCii mode, the result will
be given as a floating-point number (NR3
format) followed by integers (NR1 for-
mat). In :FORMat REAL mode, the result
will be given as an eight-byte block con-
taining the floating-point measured value,
followed by a four-byte block containing
the integer timestamp count, where each
count represents 125 nanoseconds.
When doing readouts in array form, with
:FETCh :ARRay?, :READ :ARRay? or
:MEASure :ARRay?, the response will
consist of alternating measurement values
and timestamp values, formatted the same
way as for scalar readout. All values will
be separated by commas.
For :FETCh:SCALar?, :READ:SCALar?
and :MEASure:SCALar?, the readout
will consist of two values instead of one.
6-6 Format Subsystem
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Using the Subsystems
Input Subsystems
PM6685
INP:SLOP POS
INP:SLOP NEG
INP:FILT OFF
INP:FILT ON
Comparator
1
A
INP:IMP 1E6
INP:IMP 50
INP:HYST <value in Volt>
INP:LEV <value in Volt>
Trigger points
t
0V
Reset points
Figure 6-1
Summary of PM6685 input amplifier settings.
Input Subsystems 6-7
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Using the Subsystems
PM6680B/PM6681
INP:COUP AC
INP:COUP DC
INP:FILT OFF
INP:FILT ON
INP:SLOP POS
INP:SLOP NEG
1
A
INP:IMP 1E6
INP:IMP 50
INP:ATT 1
INP:ATT 10
INP2:COUP AC
INP2:COUP DC
INP2:COMM ON
INP2:COMM OFF
INP2:SLOP POS
INP2:SLOP NEG
2
4
B
INP2:IMP 1E6 INP2:IMP 50
INP2:ATT 1
INP2:ATT 10
INP4:SLOP POS
INP4:SLOP NEG
E
Figure 6-2
Summary of PM6680B / PM6681 input amplifier settings.
6-8 Input Subsystems
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Using the Subsystems
Measurement Function
The Measure function group has a differ- details about the signal you are going to
ent level of compatibility and flexibility measure, for example:
than other commands. The parameters
MEASure:FREQ?8208MHz,1
SEND→
used with commands from the Measure
group describe the signal you are going to
measure. This means that the Measure
functions give compatibility between in-
struments, since you don’t need to know
anything about the instrument you are us-
ing.
Where: 20 MHz is the expected value,
which can, of course, also be sent as
20E6, and 1 is the required resolution.
(1 Hz)
Also the channel numbers can be speci-
fied, for example:
MEASure:FREQ?8(@3)
SEND→
MEASure?
MEASure:FREQ?820E6,
SEND→
1,(@1)
This is the most simple query to use, but
it does not offer much flexibility. The
MEASure? query lets the instrument con-
figure itself for an optimal measurement,
starts the data acquisition, and returns the
result.
CONFigure; READ?
The CONFigure command causes the in-
strument to choose an optimal setting for
the specified measurement. CONFigure
may cause any device setting to change.
READ? starts the acquisition and returns
the result.
n Example:
MEASure:FREQ?
SEND→
This will execute a frequency measurement
and the result will be sent to the controller.
The instrument will select a setting for this
purpose by itself, and will carry out the re-
quired measurement as “well” as possible;
moreover, it will automatically start the
measurement and send the result to the
controller.
This sequence operates in the same way
as the MEASure command, but now it is
possible to insert commands between
CONFigure and READ? to fine tune the
setting of a particular function. For exam-
ple, you can change the input impedance
from 1 MΩ to 50 Ω.
You may add parameters to give more
Measurement Function 6-9
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Using the Subsystems
n Example:
20E6 is the expected signal value
1 is the required resolution
CONFigure:FREQ82E6,1
SEND→
INPut:IMPedance1E86
SEND→
2E6 is the expected value
1 is the required resolution (1Hz)
Sets input impedance to 1 MΩ
INPut:IMPedance508OHM
SEND→
INITiate
SEND→
Sets input impedance to 50 Ω
Starts measurement
READ?
SEND→
FETCh?
SEND→
Starts the measurement and returns the
result.
Fetches the result
Versatility of measurement com-
mands
CONFigure;INITiate;FETCh?
MEASure?
Simple to use, few addi-
tional possibilities.
The READ? command can be divided
into the INITiate command, which starts
the measurement, and the FETCh? com-
mand, which requests the instrument to
return the measuring results to the con-
troller.
CONFigure
READ?
Somewhat more difficult,
but some extra possibili-
ties.
CONFigure
INITiate
FETCh?
Most difficult to use, but
many extra features.
n Example:
CONFigure:FREQ820E6,1
SEND→
6-10 Measurement Function
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Using the Subsystems
Output Subsystem
The analog output is turned off as a de- Scaling Factor
fault. You turn it on/off and set the scal-
The scaling factor has two functions:
ing factor under ANALOG OUT in the
aux menu.
– Its exponent selects which digits to output
on the analog output.
– Its value sets what reading should represent
full scale.
c As o default, the scaling factor is 1 (1E0).
S
f
c
a
l
i
n
g
f
a
t
r
s
This means that the full scale value is
e
l
e
c
t
s
u
l
l
s
c
a
l
e
v
a
l
u
e
.
g
s
6
7
8
9
0
o
n
t
h
e
d
i
s
p
l
a
y
s
c
a
l
i
n
g
f
a
c
t
o
1
0.999 t andr r the analog output converts the
i
v
3
e
.
s
3
8
V
w
i
t
h
s
c
a
l
i
n
g
f
a
c
4
fractiono (digits to the right of the decimal
point) to a voltage.
c
a
l
i
n
g
f
a
c
t
o
r
1
The scaling factor should be:
1
5
V
r
a
n
g
e
Scaling factor=
full scale value
where full scale value is the value for
which you want the analog output to out-
put its maximum voltage (5 V).
A
c
N
A
L
O
G
O
U
T
o
n
n
e
c
t
o
r
S
i
c
a
l
i
n
g
e
x
p
o
n
e
n
t
m
o
v
e
s
5
0
/
1
M
5
0
/
1
M
Example:
n
s
e
r
t
i
o
n
p
o
i
n
t
1
2
V
r
Ω
m
Ω
s
-
5
0
5
Ω
0
3
5
0
V
p
-
1
M
– Take a measurement result, for instance:
A
n
a
l
o
g
O
u
t
=
O
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– Represent this result without exponent:
12345678.90 Hz
Figure 6-3
The analog output func-
tion.
– Multiply this value with the scaling factor,
for instance 0.001.
12345.67890
– Take the fractional part of the result:
.67890
Output Subsystem 6-11
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Using the Subsystems
– This is the value that will determine the
output voltage; .00 will give 0 V and .99
will give 5 V. This means that the reading
will give:
n Resolution
The analog output range is 0 to 5 V in
250 steps, so one step is 0.02 V. If the
scaling factor is 1, one such step is taken
each time the display changes with
X.004, and if the scaling factor is 4, one
step is taken each time the display
changes with X.001.
.67890*5=3.3945 V.
This is ouput as 3.38 V due to the 0.02 V
resolution of the analog output.
The X in the above paragraph can be any
digit a and does not influence the output
D
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1
voltage. If the = display changes from
0.996 to 1.000, the voltage drops from
4.98 V to 0V. If the display value in-
creases further, the output voltage starts
Same exponent, opposite sign
Output voltage
4.98 V
Scaling factor 1
S
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0.004
20mV
Figure 6-4
To use the shown deci-
mal point as reference,
set the exponent of the
scaling factor to the
0.00V
0.000
Displayed
value
1.000
0.996
2.000
1.996
Output voltage
4.98 V
Scaling factor 4
same value as the expo-
nent of the measurement
result but with opposite
sign.
0.001
20mV
0.00V
Displayed
value
0.000
0.250
0.500
0.249
0.499
Figure 6-5
Output voltage versus
displayed value for two
different scaling factors.
to increase again; see .
6-12 Output Subsystem
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Using the Subsystems
Sense Command
Subsystems
Depending on application, you can select n Prescaling
different input channels and input charac-
For all measuring functions except fre-
quency, the maximum input A frequency
is 160 MHz.
teristics.
n Switchbox
To extend the range for frequency mea-
surements, PM6680B and PM6685 can
divide (scale) the input A frequency by
two, while PM6681 scales by four.
In automatic test systems, it is difficult to
swap BNC cables when you need to mea-
sure on several measuring points. With
PM6680B/1 you can select from three
different basic inputs (A, B and E), on
which the counter can measure directly
without the need for external switching
devices. With PM6685 you can select
from two different basic inputs (A and E).
When using channel 1, the counter auto-
matically selects this scaling factor when
measuring FREQ A, giving 300 MHz
max frequency for PM6681 and PM6685,
and 225 MHz for PM6680B.
For all other measuring functions, and for
frequency if you select negative slope,
the counter does not divide the signal and
the max repetition rate is 160 MHz.
Sense Command Subsystem 6-13
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Using the Subsystems
Status Subsystem
Introduction
– The Operation Status Register reports the
status of the CNT-8X measurement cycle
(see also ARM-TRIG model, page 6-27).
Status reporting is a method to let the
controller know what the counter is do-
ing. You can ask the counter what status
it is in whenever you want to know.
– The Questionable Data Register reports
when the output data from the CNT-8X
may not be trusted.
You can select some conditions in the
counter that should be reported in the Sta-
tus Byte Register. You can also select if
some bits in the Status Byte should gen-
erate a Service Request (SRQ).
– The Device Register 0 reports when the
measuring result has exceeded prepro-
grammed limits.
– The Output Queue status reports if there
is output data to be fetched.
(An SRQ is the instrument’s way to call
the controller for help.)
– The Error Queue status reports if there
are error messages available in the error
queue.
Status Reporting Model
– The Status Byte contains eight bits. Each
bit shows if there is information to be
fetched in the above described registers
and queues of the status structure.
n The Status Structure
The status reporting model used by
CNT-8X is standardized in IEEE 488.2
and SCPI, so you will find similar status
reporting in most modern instruments.
Figure 6-6 shows an overview of the
complete CNT-8X status register struc-
ture. It has four registers, two queues, and
a status byte:
Using the Registers
Each status register monitors several con-
ditions at once. If something happens to
any one of the monitored conditions, a
summary bit is set true in the Status Byte
Register.
– The Standard Event Register reports the
standardized IEEE 488.2 errors and condi-
tions.
Enable registers are available so that you
can select what conditions should be re-
6-14 Status Subsystem
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Using the Subsystems
ported in the status byte, and what bits in tive, the bit in the event register is set
the status byte should cause SRQ.
true. When the condition changes from
active to inactive, the event register bits
are not affected at all.
A register bit is TRUE, i.e., some-
thing has happened, when it is
set to 1. It is FALSE when set to
0.
+
When you read the contents of a register,
the counter answers with the decimal sum
of the bits in the register.
Note that all event registers and the status
byte records positive events. That is when
a condition changes from inactive to ac-
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Figure 6-6
CNT-8X Status register structure.
Status Subsystem 6-15
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Using the Subsystems
Example:
one or more data bytes. When the queue
is empty, the queue status bit is set false.
The counter answers 40 when you ask for
the contents of the Standard Event Status
Register.
Status of the Output Queue (MAV)
The MAV (message available) queue sta-
tus message appears in bit 4 of the status
byte register. It indicates if there are bytes
ready to be read over the GPIB in the
GPIB output queue of the instrument.
The output queue is where the formatted
data appears before it is transferred to the
controller.
– Convert this to binary form. It will give
you 101000.
– Bit 5 is true showing that a command error
has occurred.
– Bit 3 is also true, showing that a device de-
pendent error has occurred.
The controller reads this queue by ad-
dressing the instrument as a talker. The
command to do this differs between dif-
ferent programming languages. Examples
are IOENTERS and IBREAD.
Use the same technique when you pro-
gram the enable registers.
– Select which bits should be true.
– Convert the binary expression to decimal
data.
Status of the Error Message Queue
(EAV)
– Send the decimal data to the instrument.
The EAV (error message available)
queue status message appears in bit 2 of
the status byte register. Use the
:SYSTem:ERRor? query to read the er-
ror messages. Chapter 21 explains all
Clearing/Setting all bits
– You can clear an enable register by pro-
gramming it to zero. You can set all bits
true in a 16-bit event enable register by
programming it to 32767 (bit 16 not used). possible error messages .
– You set all bits true in 8-bit registers by
n Using the Status Byte
programming them to 255 (Service Re-
quest Enable and Standard Event Enable.)
The status byte is an eight bit status mes-
sage. It is sent to the controller as a re-
sponse to a serial poll or a *STB? query,
contains a summary message from the
status structure. You can select what bits
in the status byte should generate a ser-
vice request to alert the controller.
n Using the Queues
The two queues, where CNT-8X stores
output data and error messages, may con-
tain data or be empty. Both these queues
have their own status bit in the Status
Byte. If this bit is true there is data to be
fetched.
When a service request occurs, the
SRQ-line of the GPIB will be activated.
Whether or not the controller will react
on the service request depends on the
controller program. The controller may
be interrupted on occurrence of a service
When the controller reads data, it will
also remove the data from the queue. The
queue status bit in the status byte will re-
main true for as long as the queue holds
6-16 Status Subsystem
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Using the Subsystems
request, it may regularly test the Example:
SRQ-line, it may regularly make serial
poll or *STB?, or the controller may not
react at all. The preferred method is to
use SRQ because it presents a minimum
of disturbance to the measurement pro-
cess.
*SRE816
This sets bit 4 (16=24) in the service request
makes the instrument signal SRQ
when a message is available in the
output queue.
Selecting Summary Message to Gen-
erate SRQ
RQS/MSS
The original status byte of IEEE 488.1 is
sent as a response to a serial poll, and bit
6 means requested service, RQS.
The counter does not generate any SRQ
by default. You must first select which
summary message(s) from the status byte
register should give SRQ. You do that
with the Service Request Enable com-
mand *SRE <bit mask>.
IEEE 488.2 added the *STB? query and
expanded the status byte with a slightly
different bit 6, the MSS. This bit is true
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Figure 6-7
The status byte bits.
Status Subsystem 6-17
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Using the Subsystems
as long as there is unfetched data in any – *SRE <bit mask> Selects which bits
in the status byte should cause a Service
Request
of the status event registers.
– The Requested Service bit, RQS, is set true
when a service request has been signalled.
If you read the status byte via a Serial Poll,
bit 6 represents RQS. Reading the status
byte with a serial poll will set the RQS bit
false, showing that the status byte has been
read.
A programming example using status re-
porting is available in the Programming
Examples in chapter 4.
Reading and Clearing Status
n Status Byte
– The Master Summary Status bit, MSS, is
set true if any of the bits that generates
SRQ is true. If you read the status byte us-
ing *STB?, bit 6 represents MSS. MSS re-
mains true until all event registers are
cleared and all queues are empty.
As explained earlier, you can read the sta-
tus byte register in two ways:
Using the Serial Poll (IEEE-488.1 de-
fined).
– Response:
Setting up the Counter to
Report Status
– Bit 6: RQS message, shows that the
counter has requested service via the
SRQ signal.
Include the following steps in your pro-
gram when you want to use the status re-
porting in CNT-8X:
– Other bits show their summary mes-
sages
– *CLS Clears all event registers and the er-
ror queue
– A serial poll sets the RQS bit
FALSE, but does not change other
bits.
– *ESE <bit mask> Selects what condi-
tions in the Standard Event Status register
should be reported in bit 5 of the status
byte
Using the Common Query *STB?
– Response:
– :STATus:OPERation:ENABle <bit
mask> Selects which conditions in the
Operation Status register should be re-
ported in bit 7 of the status byte
– Bit 6: MSS message, shows that
there is a reason for service request.
– Other bits show their summary mes-
sages.
– :STATus:QUEStionable:ENABle
<bit mask> Selects which conditions in
the Questionable Status register should be
reported in bit 3 of the status byte
– Reading the response will not alter
the status byte.
– :STATus:DREGister0:ENABle
<bit mask> Selects which conditions
in Device Register 0 should be reported in
bit 0 of the status byte
n Status Event Registers
You read the Status Event registers with
the following queries:
6-18 Status Subsystem
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Using the Subsystems
– *ESR? Reads the Standard Event Status
register
measurement cycle by reading the Opera-
tion Status register.
– :STATus:OPERation? Reads the
Operation Status Event register
Reading the Event Register will always
show that a measurement has started, that
waiting for triggering and bus arming has
occurred and that the measurement is
stopped. This information is not very use-
ful.
– :STATus:QUEStionable? Reads the
Questionable Status Event register
– :STATus:DREGister0? Reads Device
Event register
Reading the Condition Register on the
other hand gives only the status of the
measurement cycle, for instance “Mea-
surement stopped”.
When you read these registers, you will
clear the register you read and the sum-
mary message bit in the status byte.
You can also clear all event registers with
the *CLS (Clear Status) command.
Although it is possible to read the
condition registers directly, we
recommend that you use SRQ
when monitoring the measure-
ment cycle. The measurement
cycle is disturbed when you read
condition registers.
+
n Status Condition Registers
Two of the status register structures also
have condition registers: The Status Op-
eration and the Status Questionable regis-
ter.
n Summary:
The condition registers differ from the
event registers in that they are not
latched. That is, if a condition in the
counter goes on and then off, the condi-
tion register indicates true while the con-
dition is on and false when the condition
goes off. The Event register that monitors
the same condition continues to indicate
true until you read the register.
The way to work when writing your bus
program is as follows:
Set up
– Set up the enable registers so that the
events you are interested in are summa-
rized in the status byte.
– Set up the enable masks so that the condi-
tions you want to be alerted about generate
SRQ. It is good practice to generate SRQ
on the EAV bit. So, enable the EAV-bit via
*SRE.
– :STATus:OPERation:CONDition?
Reads the Operation Status Condition reg-
ister
– :STATus:QUEStionable:CONDi-
tion? Reads the Questionable Status
Condition register
Check & Action
– Check if an SRQ has been received.
Reading the condition register will not af-
fect the contents of the register.
– Make a serial poll of the instruments
on the bus until you find the instru-
ment that issued the SRQ (the instru-
ment that has RQS bit true in the Sta-
tus Byte).
Why Two Types of Registers?
Let’s say that the counter measures con-
tinuously and you want to monitor the
Status Subsystem 6-19
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Using the Subsystems
Standard Status Registers
– When you find it, check which bits
in the Status Byte Register are true.
These registers are called the standard
status data structure because they are
mandatory in all instruments that fulfill
the IEEE 488.2 standard.
– Let’s say that bit 7, OPR, is true.
Then read the contents of the Opera-
tion Status Register. In this register
you can see what caused the SRQ.
– Take appropriate actions depending
on the reason for the SRQ.
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Figure 6-8
Standard status data structures, overview.
6-20 Status Subsystem
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Using the Subsystems
n Standard Event Status Register
Bit 3 (weight 8) — Device-dependent
Error (DDE)
Bit 7 (weight 128) — Power-on (PON)
A device-dependent error is any device
operation that did not execute properly
because of some internal condition, for
instance error queue overflow. This bit
shows that the error was not a command,
query or execution error.
Bit 2 (weight 4) — Query Error (QYE)
The output queue control detects query er-
rors. For example the QYE bit shows the
unterminated, interrupted, and deadlock
conditions. For more details, see ‘Error re-
porting’ on page 3-17.
Figure 6-9
Bits in the standard event
status register
Shows that the counter’s power supply has
been turned off and on (since the last time
the controller read or cleared this register).
Bit 1 (weight 2)—Request Control (RQC)
Shows the controller that the device
wants to become the active control-
ler-in-charge. Not used in the CNT-8X.
Bit 6 (weight 64)—User Request (URQ)
Shows that the user has pressed a key on
the front panel of CNT-8X (except LO-
CAL/PRESET). The URQ bit will be set
regardless of the remote local state of the
counter. The purpose of this signal is, for
example, to call for the attention of the
controller by generating a service request.
Bit 0 (weight 1) — Operation Complete
(OPC)
The counter only sets this bit TRUE in re-
sponse to the operation complete com-
mand (*OPC). It shows that the counter
has completed all previously started ac-
tions.
Bit 5 (weight 32) — Command Error
(CME)
n Summary, Standard Event
Status Reporting
Shows that the instrument has detected a
command error. This means that it has re-
ceived data that violates the syntax rules
for program messages.
*ESE <bit mask>
Enable reporting of Standard Event Sta-
tus in the status byte.
Bit 4 (weight 16) — Execution Error
(EXE)
*SRE 32
Enable SRQ when the Standard Event
structure has something to report.
Shows that the counter detected an error
while trying to execute a command. (See
command is syntactically correct, but the
counter cannot execute it, for example
because a parameter is out of range.
Status Subsystem 6-21
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Using the Subsystems
ESR?
SCPI-defined Status
Registers
Reading and clearing the event register of
the Standard Event structure.
CNT-8X has two 16-bit SCPI-defined
status structures: The operation status and
the questionable data structure. These
group is 16-bits wide while the status
byte and the standard status groups are
8-bits wide.
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Figure 6-10 Status structure 7, Operation Status Group, and Status structure 3,
Questionable Data Group are SCPI defined.
6-22 Status Subsystem
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Using the Subsystems
n Operation Status Group
Bit 5 (weight 32) — Waiting for Trigger
and/or External Arming (WFT)
This group reports the status of the
CNT-8X measurement cycle.
This bit shows when the counter is ready
to start a new measurement via the trigger
control option (488.2), for the shortest
possible trigger delay. The counter is now
O
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Bit 4 (weight 14) — Measurement
Started (MST)
6
5
4
0
1
5
8
2
5
6
3
6
2
4
1
6
This bit shows that the counter is measur-
ing. It is set when the measurement or se-
quence of measurements start.
M
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n Summary, Operation Status
d
Reporting
e
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:STAT:OPER:ENAB
Figure 6-11 Bits in the Opeation Sta-
tus Register.
Enable reporting of Operation Status in
the status byte.
*SRE 128
Bit 8 (weight 256) — Measurement
Stopped (MSP)
Enable SRQ when operation status has
someting to report.
This bit shows that the counter is not mea-
suring. It is set when the measurement, or
sequence of measurements, stops.
:STAT:OPER?
Reading and clearing the event register of
the Operation Status Register structure
Bit 6 (weight 64) — Wait for Bus Arm-
ing (WFA)
:STAT:OPER:COND?
This bit shows that the counter is waiting
for bus arming in the arm state of the trig-
ger model.
Reading the condition register of the Op-
eration Status Register structure.
Status Subsystem 6-23
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Using the Subsystems
Bit 10 (weight 1024) — Timeout for
Measurement (TIO)
Questionable Data/Signal
Status Group
The counter sets this bit true when it
abandons the measurement because the
internal timeout has elapsed, or no signal
has been detected.
This group reports when the output data
from the CNT-8X may not be trusted.
See
also
:SYST:TOUT
and
:SYST:SDET.
Q
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The counter sets this bit true when it can-
not complete the measurement due to
overflow.
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1
1
5
4
1
0
8
0
1
6
3
8
4
1
0
2
4
2
5
6
n Summary, Questionable
Data/Signal Status Reporting
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t
:STAT:QUES:ENAB <bit mask>
Enable reporting of Questionable
data/signal status in the status byte.
Figure 6-12 Bits in Questionable data
register.
*SRE 8
Enable SRQ when data/signal is ques-
tionable.
Bit 14 (weight 16384) — Unexpected
Parameter (UEP)
:STAT:QUES?
This bit shows that CNT-8X has received
a parameter that it cannot execute, al-
though the parameter is valid according
to SCPI. This means that when this bit is
true, the instrument has not performed a
measurement exactly as requested.
Reading and clearing the event register of
the Questionable data/signal Register
structure.
:STAT:QUES:COND?
Reading the condition register of Ques-
tionable data/signal Register structure.
6-24 Status Subsystem
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Using the Subsystems
Device-defined Status Structure
CNT-8X has one device-defined status status byte. Its purpose is to report when
structure called the Device Register 0. It the measuring result has exceeded pre-
summarizes this structure in bit 0 of the programmed limits.
Standard Event Register
Questionable Data Register
Condition Register
Event Register
Enable Register
Logical OR
Event Register
Enable Register
Logical OR
Operation Status Register
Device Register 0
Condition Register
Event Register
Enable Register
Logical OR
Event Register
Enable Register
Logical OR
Status Byte Register
7 6 5 4 3 2 1 0
Service Request Enable
Logical OR
SRQ signal
Figure 6-13 Device-defined status data structures ( model ).
Status Subsystem 6-25
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Using the Subsystems
You set the limits with the following *SRE 1
commands in the calculate subsystem.
Enable SRQ when a limit is exceeded.
:CALCulate:LIMit:UPPer and
:STAT:DREG0?
:CALCulate:LIMit:LOWer
Reading and clearing the event register of
Device Register structure 0.
An example on how to use limit monitor-
Examples.’
– If bit 1 is true, the high limit has been ex-
ceeded.
Bit Definition
– If bit 2 is true, the low limit has been ex-
ceeded.
Device Status Register0
STAT:DREG0:COND?
STAT:DREG0?
Power-on Status Clear
Power-on clears all event enable regis-
ters and the service request enable regis-
ter if the power-on status clear flag is set
TRUE (see the common command
*PSC.)
15 2 1 0
4
2
Monitoring of high limit
Monitoring of low limit
n Preset the Status Reporting
Structure
Figure 6-14 Bits in the Device Status
Register number 0.
You can preset the complete status struc-
ture to a known state with a single com-
mand, the STATus:PRESet command,
which does the following:
:STATus:DREGister0?
Reads out the contents
of the Device Status
event Register 0 and
clears the register.
– Disables all bits in the Standard Event
Register, the Operation Status Register, and
the Questionable Data Register
Bit 2 (weight 4) — Monitor of Low Limit
– Enables all bits in Device Register 0
This bit is set when the low limit is
passed from above.
– Leaves the Service Request Enable Regis-
ter unaffected.
Bit 1 (weight 2) — Monitor of High Limit
This bit is set when the high limit is
passed from below.
n Summary, Device-defined
Status Reporting
:STAT:DREG0:ENAB <bit mask>
Enable reporting of device-defined status
in the status byte.
6-26 Status Subsystem
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Using the Subsystems
Trigger/Arming Subsystem
The SCPI TRIGger subsystem enables syn- The ARM-TRIG Trigger
chronization of instrument actions with
specified internal or external events. The
following list gives some examples.
Configuration
Figure 6-15 gives a typical trigger config-
uration, the ARM-TRIG model. The con-
figuration contains two event-detection
layers: the ‘Wait for ARM’ and ‘Wait for
Instrument Action
TRIG’ states.
Some examples of events to synchronize
with are as follows:
– measurement
ABORt
– bus trigger
Default state
after power-on
or reset
Idle
*RST
pon
– external signal level or pulse
– 10 occurrences of a pulse on the external
trigger input
No longer
initiated
Trigger system initiated
– other instrument ready
– signal switching
Initiated
Trigger system
initiated
Completed No.
of ARM loops
Still initiated
– input signal present
– 1 second after input signal is present
– sourcing output signal
– switching system ready
Wait for ARM
Arm Layer
Completed
ARM conditions
satisfied
No. of TRIGger
loops
Wait for TRIG
Trigger Layer
TRIGger conditions
satisfied
Instrument
Actions
complete
Instrument
Actions
Figure 6-15 Generalized ARM-TRIG
model.
Trigger/Arming Subsystem 6-27
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Using the Subsystems
This trigger configuration is sufficient for
most instruments. More complex instru-
ments, such as the CNT-8X, have more
ARM layers.
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The ‘Wait for TRIG’ event-detection
layer is always the last to be crossed be-
fore instrument actions can take place.
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Structure of the IDLE and
INITIATED States
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When you turn on the power or send
*RST or :ABORT to the instrument, it
sets the trigger system in the IDLE state;
see .
Figure 6-16 Flow diagram of IDLE
and INITIADED layers.
The trigger system will exit from the
IDLE state when the instrument receives
an INITiate:IMMediate. The in-
strument will pass directly through the
INITIATED state downward to the next
event-detection layers (if the instrument
contains any more layers).
n Structure of an Event-detection
Layer
The
general
structure
of
all
event-detection layers is identical and is
roughly depicted by the flow diagram in
In each layer there are several program-
mable conditions, which must be satisfied
to pass by the layer in a downward direc-
tion:
The trigger system will return to the INI-
TIATED state when all events required
by the detection layers have occurred and
the instrument has made the intended
measurement. When you program the
trigger system to INITiate:CONTin-
uous ON, the instrument will directly
exit the INITIATED state moving down-
ward and will repeat the whole flow de-
n Forward Traversing an
Event-detection Layer
After initiating the loop counters, the in-
strument waits for the event to be de-
tected. You can select the event to be
detected by using the <layer>:SOURce
scribed
above.
When
INITiate:CONTinuous is OFF,
the trigger system will return to the IDLE
state.
command.
:ARM:LAYer2:SOURce BUS
For
example:
You can specify a more precise character-
istic of the event to occur. For example:
:ARM:LAYer:DELay 0.1
You may program a certain delay be-
tween the occurrence of the event and en-
tering into the next layer (or starting the
device actions when in the TRIGger
6-28 Trigger/Arming Subsystem
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Using the Subsystems
layer). This delay can be programmed by
using the <layer>:DELay command.
Triggering
n *TRG Trigger Command
n Backward Traversing an
Event-detection Layer
The trigger command has the same func-
tion as the Group Execute Trigger com-
mand GET, defined by IEEE 488.1.
The number of times a layer event has to
initiate a device action can be pro-
grammed by using the <layer>:COUNt
When to use *TRG and GET
command.
:TRIGger:COUNt
strument to measure three times, each
measurement being triggered by the spec-
ified events.
For
example:
causes the in-
The *TRG and the GET commands have
the same effect on the instrument. If the
Counter is in idle, i.e., not parsing or exe-
cuting any commands, GET will execute
much (≈ 20 µs) faster than *TRG
(≈ 4 ms) since the instrument must al-
ways parse *TRG.
3
Trigger/Arming Subsystem 6-29
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Using the Subsystems
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6-30 Trigger/Arming Subsystem
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How to Measure Fast
Timeout
Introduction
Turn on timeout and set the time longer
than the expected measurement cycle.
Then wait for the timeout period, and
take actions if you got timeout.
The CNT-8X counters can complete a
measurement cycle in many different
ways, each with its own advantage. This
means that your first step is to select a ba-
sic “measurement scenario” based on the
requirements of the measurement. This
chapter contains some measurement sce-
narios that you can choose from.
If the measurement time is long, you may
have to wait many seconds or even min-
utes until timeout, just to learn that the
measurement never started.
Measurement started
These counters can measure with impres-
sive speed if you program them correctly.
You will find guidelines for speed im-
provements in each of the described mea-
surement scenarios.
Before starting a measurement, set up the
status reporting system so that you get a
Service
Request
on
Measure-
ment-in-progress, bit 4 in the Operation
Status Event Register. Check this with se-
rial poll after a reasonable time when the
measurement ought to be started, lets say
after 100ms (time dependent on input sig-
nal frequency). If the bit is true, continue.
If false, abort the measurement and check
the signals, alert the operator etc.
Controller Synchronization
The start of measurements can either be
individually or block synchronized by the
controller. The instrument-to-controller
synchronization deals with how to start a
measurement or sequence of measure-
ments and to read data in the most effi-
cient way. You can also synchronize the
measurement with the measuring object
more accurately by using external control
(arming), but this is not described here.
n Stop
You must also know when the measure-
ment is completed in order to read out the
results. Should you read results or send
other commands before the measurement
is completed, the measurement will be in-
terrupted.
Measurement Cycle
Synchronization
You can of course let the controller wait
until you are absolutely certain that the
result is ready, before you fetch it. But it
is better to use *OPC to get an Operation
Complete status message, or *OPC? to
get an ASCii “1” in the output queue,
when the measurement is ready.
It is a good practice to check that the
measurement proceeds as planned when
the controller has started a measurement,
or block of measurements.
n Start
If the input signal fails, or there is no
arming etc., the measurement cycle will
not start.
*OPC and *OPC? are common com-
7-2 Introduction
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How to Measure Fast
*OPC reports when operation is com- MEASUREMENT State
plete, via the Status Subsystem described
on page 6-14.
– The counter measures. It monitors the
hardware and controls the measurement
time. If block measurement mode is used,
(ARM:COUN or TRIG:COUN8³2) the
counter stays in this state until all measure-
ments inside the block has been made.
Rough Trigger
Subsystem
Description
Different actions cause the trigger sub-
system to change between the different
states. The transitions are shown in . The
status is reflected in status byte
:STATus:OPERation:CONDition.
The trigger subsystem is the functional
part of the CNT-8X that controls the start
and stop of measurements. This is the
function that the controller interacts with
when it controls the measurement se-
quence.
S
t
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6
s
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:
A simplified model of the CNT-8X’s trig-
ger subsystem is a state-machine with
four different states. These states are as
follows:
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IDLE State
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– The counter waits for new commands. It is
not measuring
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WAIT_FOR_BUS_ARM State
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WAIT_ FOR_MEASUREMENT_TO_
START State
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– The counter waits for the input signal trig-
gering to start the measurement or block of
measurements. If the counter uses arming,
it is waiting for the specified arming event.
s
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Figure 7-1
Trigger subsystem states.
Rough Trigger Subsystem Description 7-3
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How to Measure Fast
INITiate
Some Basic
Commands
The INITiate command will normally
start a measurement or measurement se-
quence and store the result internally in
the CNT-8X. However the actual action
is to change the state of the trigger sub-
Here follows a description of some basic
CNT-8X commands that control the mea-
surement sequence.
system
from
“idle”
to
“wait_for_bus_arming”. The result of
changing the state of the trigger subsys-
tem depends on the programming of this
subsystem. For example it could be pro-
grammed to do the following:
CONFigure
The CONFigure command sets up the
counter to do the measurement specified
by the parameters of the command. The
command gives a limited number of pa-
rameter options such as:
– Make 1000 measurements.
– Wait for a GET/*TRG and then start a
measurement.
– Measurement function
– Measurement channel
– Wait for a GET and then make 534 mea-
surements.
– Number of measurements and sometimes
also the following:
– Wait for an arming pulse and make one
measurement.
– Measuring time
– Trigger level
– Wait for an arming pulse and make 234
measurements.
The counter sets up the rest of its func-
tions in the best way for the requested
measurement. This means that any instru-
ment setting may be changed by this
command.
INITiate :CONTinuous
This command sets the counter in a mode
where it continues with a new measure-
ment immediately after it has finished the
previous one. This is done by not return-
ing the trigger subsystem to the “idle”
state.
Examples:
– Set up to measure frequency:
CONF:FREQ
– Set up to do 100 frequency measurements:
CONF:ARRay:FREQ8(100)
ABORt
This command stops the current measure-
ment (if any), and sets the trigger subsys-
tem to the “idle” state. This means that
the counter is only waiting for new com-
mands.
– Set up to do 100 frequency measurements
on the A-channel:
CONF:ARRay:FREQ8(100),(@1)
– Set up to do 100 frequency measurements
on the A-channel. Expected frequency 10
MHz that should be measured with a reso-
lution of 1 Hz.
FETCh?
The FETCh query retrieves measurement
data. It could either be a single value
(SCALar) or a series of values (ARRay).
CONF:ARRay:FREQ8
(100),10e6,1,(@1)
7-4 Some Basic Commands
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How to Measure Fast
Examples:
Examples:
– Get one measurement: FETCh?
– Make a frequency measurement:
MEAS:FREQ?
– Get 100 measurements:
FETCh:ARRay?8100
– Make 100 frequency measurements:
MEAS:ARRay:FREQ?8(100)
The number of measurements is
defined by the setting of the ARM
and TRIG counters. The ARM
counter can be set directly by the
:CONF and :MEAS commands.
The :FETCh:ARRay? query pa-
rameter only decides how many
measurement results to read out.
+
– Make 100 frequency measurements on the
A-channel:
MEAS:ARRay:FREQ? (100),(@1)
– Make 100 frequency measurements on the
A-channel. The expected frequency to be
measured is 10MHz with a resolution of 1
Hz.
READ?
MEAS:ARRay:FREQ?
(100),10e6,1,(@1)
This command simply means to start a
measurement or measurement sequence
and read data.
MEAS:MEM1?, MEAS:MEM? 10
Memory Recall, Measure and Fetch Result
This query is identical to:
ABORt;INITiate;FETCh?
This command is only for PM6681. Use
it when you want to measure several pa-
rameters fast, i.e., switch quickly be-
tween measurement functions.
This means that the counter starts a mea-
surement ( single or array) after it has
aborted any previous measurements. It
also returns the result.
MEAS:MEM1? recalls the contents of
memory 1 and reads out the result,
MEAS:MEM2? recalls the contents of
memory two and reads out the result etc.
Examples:
– Start one measurement and fetch result:
READ?
The equivalent command sequence is
*RCL1;READ?
– Start measurements and fetch 100 results:
READ:ARRay?8100
The allowed range for <N> is 1 to 9. Use
the somewhat slower MEAS:MEM-
ory?8N command if you must use mem-
ories 10 to 19.
MEASure?
This query is identical to:
CONFigure;READ?
This means that the command sets up the
counter and starts a measurement/mea-
surement sequence.
TIMING
Data Format
Command
ASCII
7.9 ms
9.1 ms
REAL
6.7 ms
8.0 ms
MEAS:MEM1?
MEAS:MEM?81
*RCL8 1;READ?
10.1 ms 8.9 ms
Some Basic Commands 7-5
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How to Measure Fast
n READ?
Basic Measurement
Method
The READ? query provides a basic
mechanism for this. It ensures that the
measurement is started after the counter
receives the command. It will also send
back the result. The READ? query should
be preceded by setting up the counter by
using either CONFigure or individual
programming commands. This command
should be used if no special speed re-
quirements exists.
A basic measurement method for a sys-
tem composed of signal sources, measur-
ing object, and measuring devices will be
a simple step-by-step procedure. This
procedure goes as follows:
Step 1: Set up signal sources
Step 2: Set up measurement devices
Step 3: Trigger measurement devices
Step 4: Read data
n INIT:CONT and GET
In this method the trigger function is con-
tinuously initiated by the command INI-
Tiate:CONTinuous81. This gives you
the minimal firmware overhead if you
don’t change settings in the counter. Set
up the counter either by using CONFig-
ure, or by using individual programming
commands before starting the measuring
sequence. Setting up includes switching
on the “wait for bus trigger” function
with the following command:
Step 5: Evaluate data
The above procedure may be repeated as
many times as required.
The methods described here deal with
how you should do steps 3 and 4 in the
best and most efficient way with the
CNT-8X.
ARM:START:LAY2:SOURce8BUS.
Individually Synchronized
Measurements
As default, the counter starts a measure-
ment and sends the result to the controller
when receiving a GET or a *TRG com-
mand. This method is the fastest way to
make individually synchronized measure-
ments.
This is a method that you should use
when you need to start each measurement
externally from the controller. The most
probable reason that you should use indi-
vidually synchronized measurements is
that you need to evaluate data in real time
and make decisions depending on the ac-
quired data. An example of this could be
to tune an oscillator by measuring the
output frequency and adjust the oscillator
depending on the measured frequency.
n MEASure?
The MEASure? query sets up the coun-
ter, ensures that the measurement is
started after the command is received,
and also sends the result to the controller.
This command has the highest possible
degree of compatibility to other instru-
ments; however the command reprograms
the counter, and often you need to set up
Of the many available ways to do this
with the CNT-8X, three should be men-
tioned: READ?, INIT:CONT and GET
and MEASure?
7-6 Basic Measurement Method
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How to Measure Fast
the counter by yourself. This is primarily ble to let the controller wait for the Mes-
why we recommend the READ? query.
sage AVailable status bit to find out when
the data capture is ready. You can read
the complete array by using the
FETCH:ARRay? command. So if, for
example, the array size is 4, GET gives
the first result in the array and
FETC:ARR?83 fetches result two, three,
and four.
Block Synchronized
Measurements
In the block synchronized mode, the con-
troller only starts a sequence of measure-
ments. The counter then measures,
without any controller intervention, at the
highest possible speed. It “dumps” the re-
sults into internal memory and reads them
out for evaluation later. This method
gives the highest possible data capture
speed.
n MEAS:ARRay?
The MEASure:ARRay? query ensures
that the measurement sequence is started
after the command is received. It will also
send back the results. It also includes set-
ting up the counter. This is the command
that has the highest possible degree of
compatibility with other instruments;
however, this command reprograms the
counter and often you need to program
the counter yourself. This is why we rec-
ommend using the READ:ARRay?
query.
n READ:ARRay?
This is the basic method for starting up a
measurement sequence and reading the
data. Set up the counter using CONFigure
or individual programming commands
before sending the READ:ARRay?
query. This method will make the mea-
surements with a high measurement rate.
The speed depends on a number of indi-
vidual measurement parameters; see also
“General speed improvements” below.
The counter stores the data in its internal
memory and when it has captured all
data, it transfers the resulting array to the
controller.
General Speed
Improvements
The CNT-8X has many options to im-
prove measurement speed. Here you will
get a list of actions that you can use to
improve the measurement speed. Most of
these commands decrease the average
dead time. The dead time is the time be-
tween measurements, that is, from stop to
the next start. These actions are all gen-
eral, that is, they affect the rate of mea-
surements for all measurement methods
given above; however, they are especially
valuable for the block synchronized mea-
surements. In this mode, the dead time
can be as low as 120µs ( PM6681 ).
n INIT + GET + FETCH:ARRay?
The READ:ARRay? method has one
drawback, it includes some unwanted
firmware overhead between when the
counter receives the command and it
starts the first measurement. This can be
solved by setting up the counter to wait
for a GET before it starts the measure-
ment sequence. The default actions for
GET include sending a single result ( the
first value) when the counter has com-
pleted the sequence. This makes it possi-
General Speed Improvements 7-7
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How to Measure Fast
AUTO
Time Measurement
Resolution
One of the most timesaving commands
you can use with the CNT-8X is
The basic time measurement resolution
can be selected by using the command
SENSe:ACQ:RES8«HIGH|LOW».
When you set the resolution to low it will
be 100ns for PM6680B and PM6685, and
80ns for PM6681. Instead of the high res-
olution, which is 0.25ns for PM6680B
and PM6685, and 0.05ns for PM6681.
:INPut:LEVel:AUTO8OFF. This will
save the time it takes to determine the
trigger levels. (About 50ms/measurement
in PM6680B and PM6685, and 85ms in
PM6681.)
Display Control
If the counter does real-time calculations
and you switch to low resolution, the
measurement dead time decreases about
0.6 to 0.9ms. If the counter does not do
real-time calculations, then it saves only
about 0.05ms per measurement cycle. If
the counter does real time calculations
with the display switched on, then you
can save up to 2ms by selecting the lower
resolution.
The display can be switched off with the
command
DISPlay:ENABle8OFF. When you
switch off the display, the counter loses
the measurement data resolution informa-
tion. This means that the counter always
sends all digits independently of whether
or not they are significant. This command
reduces the dead time by about 7ms.
GPIB Data Format
Automatic Interpolator
Calibration (PM6680B/85)
You can select the format of the result
sent on the GPIB using the FORMat
command. Two options exist: ASCii and The time interpolation technique achieves
REAL. The REAL format saves a lot of the high time resolution. The counter au-
time both in the instrument and the con- tomatically calibrates these interpolators
troller for converting data. However, once per measurement cycle. You can
when the counter uses the REAL format, control this automatic calibration by us-
you lose the measurement data resolution ing the command:
information. It sends the REAL format as
a block data element. This means that it
sends data as:
CAL:INT:AUTO8 «ON|OFF|ONCE».
When you switch calibration off, the
measurement cycle time decreases.
#18< 8 bytes real>.
Disabling this calibration makes the
counter more sensitive to temperature
changes. The measurement values may
drift away, which results in a larger inac-
curacy. However, when the instrument
has been switched on for more than 20
minutes and the ambient temperature is
stable within 5°C, this is no problem.
You can also easily recalibrate the
The <8 bytes real> is a double precision
binary floating-point code according to
IEEE 488.2 / IEEE 754.
7-8 General Speed Improvements
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How to Measure Fast
interpolators
CAL:INT:AUTO ONCE command.
by
using
the
40000 measure-
ments/second
(Only PM6681)
Block Measurements
PM6681 can make measure every period
of a signal with up to 40 000 Hz. This is
called “Back-to-Back” period measure-
ments and in only available via GPIB.
The high speed is obtained when the
PM6681 measures low-resolution mea-
surements directly to its internal memory.
That memory can store 6143 measure-
ment results. When full, the measurement
must be stopped, and the results fetched
by the controller. )
When dumping measurement results into
the internal memory, it is important to
program the arming and triggering coun-
ters in the best way. For maximum mea-
surement rate use the block armed mode.
To do this set:
:ARM:STARt:LAYer:COUNt81
and
TRIG:COUNt8 <N>
where <N> is the number of measure-
ments in a block.
Note also that some functions are dis-
abled to obtain high measurement speed:
You cannot use external arm/trig or
hold-off. Statistics is also disabled.
Real Time Calculation
Normally the counter calculates the re-
sults in “real time.” This means that for
each measurement, the counter immedi-
ately calculates the result based on the
raw data information in various counting
registers. It needs to do this in order to
Example: 1000 back-to-back periods
:SENS:FUNC8"PER81"
Select period as measurement function
display the result, make mathematical :INP:COUP8DC Select DC coupling
calculations, limit testing and statistical
:INP:LEV:AUTO8OFF Turn off Auto Trigger
calculations. It is possible to defer the
calculations until the controller requests
these values. The counter intermediately
stores the measurement data in a packed
format. This is done with the command:
:INP:LEV81 Set fixed trigger level
:SENS:ACQ:RES8LOW Select low resolu-
tion/high speed measurements
:SENS:INT:FORM8PACK Suspends the re-
sult calculation until the capture is
ready
:SENSe:INTernal:FORMat8 PACKed.
This is the most important com-
mand when you want to improve
the measurement rate for block
synchronized measurements.
:TRIG:COUN81000;:ARM:COUN81 Set up
PM6681 for 1000 measurements
+
:INIT Start a capture
Note: If you want a very high speed
you must set :AVER:STATE8OFF and
:ACQ:APER8 MIN.
:FETC:ARR?81000 Fetch the 1000 results
from the internal PM6681 memory
40000 measure- ments/second 7-9
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How to Measure Fast
Optimal Method
Supervising a
Process
An experienced CNT-8X programmer
knows that he can increase the process
speed to over 300 measurements/second,
by letting the counter do more and the
controller less of the job:
One typical use of a counter in the indus-
try is to measure a parameter and alert the
adjusting machinery when the parameter
gets close to the correct value. The ma-
chinery now slows down for an accurate
final adjustment of the parameter, and
stops the adjustment procedure when the
value is correct.
– Set up the counter to measure continuously
with low resolution, without displaying or
reading out any results.
– Set up limit monitoring so that the counter
issues a service request when the frequency
reaches the limit where the laser should
slow down.
An example of such a procedure is when
a laser adjusts the value of a resistor that
is connected to an oscillator. You mea-
sure the frequency of the oscillator and
the laser cuts the resistor until the oscilla-
tor oscillates at the correct frequency.
– Proceed with one of the following:
– Alternative 1: The program slows down the
laser and recalls new narrower limits from
the internal counter memory and selects
higher resolution.
Obvious Method
– Alternative 2: The program slows down the
laser and reprograms the counter to make
high resolution measurements and reports
each measurement result to the controller.
The most obvious way to do this may be
as follows:
– Let the counter measure the frequency.
– Send the result to the controller.
– The controller stops the process when the
desired result is obtained.
– Let the controller, that controls both the la-
ser cutter and the counter, decide when to
slow down the cutting procedure, and
eventually switch the laser off when the
correct frequency is obtained.
See also the limit monitoring program-
ming example in Chapter 4.
This method works fine for slow pro-
cesses but the bus transfer rate of the
counter limits the measuring speed to
around
125
measurements/s
for
PM6680B and PM6685, and 250 mea-
surements/s for PM6681. If all speed in-
creasing actions are taken, and only
around 10 measurements/s if no speed in-
creasing actions taken.
7-10 Supervising a Process
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How to Measure Fast
48.8 ms for the PM6680B.
85 ms for the PM6681.
75 ms for the PM6685.
Speed Summary
The following table summarizes the time
that can be gained when fine tuning the
measurement process.
If you should read out the measuring re-
sult to the controller add read out time to
each result. (Consult your controller man-
ual.)
The normal dead time between frequency
measurements is approximately as fol-
lows:
Individually Synchronized Measurements
Speed Improvement
Actions
Dead Time Between Measurements Including
Transfer to Controller
ASCII Data Format
Real Data Format
PM6680B PM6681 PM6685 PM6680B PM6681 PM6685
Approx. Approx. Approx. Approx. Approx.
85 ms* 75 ms
Approx.
50 ms
U
45 ms
85 ms* 75 ms
U
19 ms
12 ms
12 ms
12 ms
10 ms
9 ms
23 ms
20 ms
12 ms
12 ms
15 ms
9 ms
8 ms
20 ms
17 ms
9 ms
U
U
U
U
U
U
9 ms
9 ms
8 ms
5.5 ms
5.5 ms
U
U
U
U
4.2 ms
4.2 ms
U
8 ms
Turning the real-time calculations on/off will not affect the dead time because the
calculations are still done inside the measurement loop during the output of data.
+
* It takes longer time for PM6681 to determine trigger levels than for PM6680B,
why? The reason is that PM6681 must find the correct level from 16 times as many
triggerlevel setting steps than thePM6680B/85 (1.25 mV steps versus 20mV steps).
Speed Summary 7-11
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How to Measure Fast
S
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7-12 Speed Summary
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How to Measure Fast
Block Synchronized Measurements
(:ARM:STARt:LAYer:COUNt 1 and TRIG:COUNt <N>)
Speed Improvement Actions
Dead Time Between Measurements
PM6680B
PM6681
4.5 ms
PM6685
9 ms
2 ms
9 ms
U
U
U
1.3 ms
2.5 ms
0.6 ms
0.6 ms
U
U
0.5 ms
0.5 ms
0.12 ms
0.025 ms*
U
1: The GPIB format command will not affect the dead time for the block synchro-
nized mode because the counter captures all data before transferring it to the con-
troller.
+
+
2: Switching the real time calculations on/off In the block synchronized mode will
significantly decrease the dead time; however, the time for calculations ( 2 ms for
PM6680B/85 and 1 ms for PM6681) is added to the transfer time.
* In PM6681, low resolution is used for Back-to-Back period measurements.
The measuring time has no effect in this mode. Only the Timestamps are used.
Speed Summary 7-13
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How to Measure Fast
S
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o
c
c
k
k
d
d
a
a
t
t
a
a
,
,
a
n
l
o
l
0
0
0
7
5
2
5
0
5
0
0
0
7
5
2
5
0
5
0
0
0
0
0
1
0
,
0
1
1
E
-
0
4
u
0
,
0
1
1
8
E
-
0
7
8
,
0
0
1
E
E
-
0
-
0
7
4
u
M
e
a
s
r
e
m
e
n
t
T
i
m
e
M
e
a
s
r
e
m
e
n
t
T
i
m
e
S
p
e
e
d
,
B
l
o
c
k
s
y
n
c
.
m
e
a
s
u
r
e
m
e
n
t
s
P
M
6
6
8
1
Calculating the Measurement
Speed
8
7
6
5
4
3
2
1
0
When opimizing your program for speed,
add the measuring time you use to the
dead time, and subtract the time gain for
B
B
l
l
o
o
c
c
k
k
d
d
a
a
a
,
a
l
l
t the timesaving commands you intend to
t
a
,
n
o
use; all times should be expressed in sec-
onds:
1
=
Meas.time + DeadTime- TimeGain
å
8
E
-
0
5
8
E
-
0
5
0
,
0
0
5
0
,
5
0
,
0
5
6
,
4
E
-
5
0
E
7
-
0
4
= number of measurements / second.
M
e
a
s
u
r
e
m
e
n
t
T
i
m
e
Where:
Meas.time is the measurement time
you use.
Deadtime is the deadtime between
measurements after preset. see page
7-11.
Timegain is the timegain in the table
on page 7-15.
7-14 Speed Summary
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How to Measure Fast
Timesaving Com-
mands
Time Gain in ms
Sacrifice
PM6680B PM6681 PM6685
Freq
(23)
Freq
Freq
(23)
FREQ:RANG:LOW8MAX
10kHz lower freq. limit for AUTO. This
Timesaving is only possible when
AUTO is on.
50kHz lower freq. limit for AUTO. This
Timesaving is only possible when
AUTO is on.
(55)
INP:LEV:AUTO8OFF
DISP:ENAB8OFF
You have to set trigger levels manually.
40
5.4
70
3.5
52
7.7
Only the controller can read the result.
CAL:INT:AUTO8OFF
You must instruct the counter to cali-
brate the interpolators once in a while
to maintain accuracy.
0.22
N.A.
0.22
SENS:ACQ:RES8LOW
Works up to about 40kHz. The resolu-
tion of each measurement drops to
100ns for PM6680B/85 and 80ns for
PM6681
0.81
0 / 0.1
0.81
(PM6681 Only: Gives Back-to-back
measurements in period, i.e. every pe-
riod in a block is measured)
TRIG:COUNT82100
TRIG:COUNT86143
INT:FORM8PACK
No sacrifice, the program loop in the
counter gets shorter, saving time.
0.69
N.A.
1.15
N.A.
4.2
0.69
N.A.
1.15
You cannot use limit monitoring, math-
ematics etc. in the CALC subsystem,
nor the Display or the Output subsys-
tems.
1.2
TRIG:COUNT81000(o
r more)
STAT:OPER:ENAB80
ARM:STA:LAY2:SOUR
8 IMM
These commands (all together) will in-
crease measurement speed the last
step from about 4000 to over 8000
measurements/s
N.A.
0.13
N.A.
INP:LEV:AUTO8OFF
(All together)
FORM:TINF8OFF
No timestamping possible. This only
influences the read. Time stamps are
always registred internally.
N.A.
0
N.A.
All these time gain estimates are approximations valid for frequency A mea-
surements and may be changed without notice. The time gain/loss depends on
measuring function.
+
Speed Summary 7-15
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How to Measure Fast
Single “Speed Switch”
Command for PM6680B/85
Single “Speed Switch”
Command for PM6681
Since many parameters must be set to get Since many parameters must be set to get
the highest measuring speed, it is simpler the highest measuring speed, it is simpler
if you use the macro function:
if you use the macro function:
Send the following lines to turn on mac- Send the following lines to turn on mac-
ros; define one macro called FASTFREQ ros; define one macro called FASTFREQ
and one macro called SLOWFREQ.
and one macro called SLOWFREQ.
*EMC81
SEND→
*EMC81
SEND→
*DMC8‘FastFreq’,
SEND→
“:ACQ:APER8MIN;
*DMC8‘FastFreq’,
SEND→
“:ACQ:APER8MIN;
:AVER:STAT8OFF;
:INP:LEV:AUTO OFF;
:DISP:ENAB8OFF;
:CAL:INT:AUTO8OFF;
:SENS:ACQ:RES8LOW”
:AVER:STAT8OFF;
:INP:LEV:AUTO8OFF;
:DISP:ENAB8OFF;
:INT:FORM8PACK;
:SENS:ACQ:RES8LOW;
:FORM:TINF8OFF;
:TRIG:COUNT86143;
:STAT:OPER:ENAB80;
:ARM:STA:LAY2:SOUR8IMM"
*DMC8‘SlowFreq’,
SEND→
“:ACQ:APER82008ms;
:AVER:STAT8ON;
:INP:LEV:AUTO8ON;
:DISP:ENAB8ON;
:CAL:INT:AUTO8ON;
:SENS:ACQ:RES8HIGH”
*DMC8‘SlowFreq’,
SEND→
“:ACQ:APER8200 ms;
:AVER:STAT8ON;
Now you just have to send FASTFREQ to
the counter to get high measurement
speed for frequency measurements, and
SLOWFREQ to return to normal measur-
ing speed.
:INP:LEV:AUTO8ON;
:DISP:ENAB8ON;
:INT:FORM8REAL;
:SENS:ACQ:RES8HIGH;
:FORM:TINF8ON;
:TRIG:COUNT81;
Note that these macros include
all speed-increasing commands
from the table on the previous
page. Omit the ones you do not
want to use in your application
and the ones that do not apply to
your counter.
:STAT:OPER:ENAB81;
:ARM:STA:LAY2:SOUR8BUS"
+
Now you just have to send FASTFREQ to
the counter to get high measurement
speed for frequency measurements, and
SLOWFREQ to return to normal measur-
ing speed.
Note that these macros include
all speed-increasing commands
from the table on the previous
page. Omit the ones you do not
want to use in your application.
+
7-16 Speed Summary
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Error Messages
empty, and the :SYSTem:ERRor?
query will return:
Read the Error/Event Queue
You read the error queue with the :SYS-
Tem:ERRor? query.
0, “No error”
When errors occur and you do not read
these errors, the Error Queue may over-
flow. Then the instrument will overwrite
the last error in the queue with:
Example:
:SYSTem:ERRor?
–100, “Command Error”
SEND→
READ←
The query returns the error number fol-
lowed by the error description.
–350, “Queue overflow”
If more errors occur they will be dis-
carded.
If more than one error occurred, the query
will return the error that occurred first.
When you read an error, you will also re-
move it from the queue. You can read the
next error by repeating the query. When
you have read all errors, the queue is
Read more about how to use er-
ror reporting in the Introduction to
SCPI chapter
+
Command Errors
Error Description Description/Explanation/Examples
Error
Number
No error
0
Command error
This is the generic syntax error for devices that can-
not detect more specific errors. This code indicates
only that a Command Error defined in IEEE-488.2,
11.5.1.1.4 has occurred.
–100
Invalid character
A syntactic element contains a character which is in-
valid for that type; for example, a header containing
an ampersand, SETUP&. This error might be used
in place of errors –114, –121, –141, and perhaps
some others.
–101
Syntax error
An unrecognized command or data type was encoun-
tered; for example, a string was received when the
counter does not accept strings.
–102
–103
Syntax error; unrec-
ognized data
Invalid separator
The parser was expecting a separator and encoun-
tered an illegal character; for example, the semico-
lon was omitted after a program message unit,
∗EMC1:CH1:VOLTS5.
Data type error
The parser recognized a data element different than
one allowed; for example, numeric or string data
was expected but block data was encountered.
–104
8-2 Error Code 0 to -104
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Error Messages
Command Errors
Error
Number
Error Description Description/Explanation/Examples
GET not allowed
A Group Execute Trigger was received within a pro-
gram message (see IEEE-488.2, 7.7).
–105
Parameter not al-
lowed
More parameters were received than expected for
the header; for example, the ∗EMC common com-
mand accepts only one parameter, so receiving
∗EMC0,,1 is not allowed.
–108
Missing parameter Fewer parameters were received than required for
the header; for example, the ∗EMC common com-
mand requires one parameter, so receiving ∗EMC is
not allowed.
–109
Command header
error
An error was detected in the header. This error
message is used when the counter cannot detect
the more specific errors described for errors –111
though –119.
–110
–111
Header separator
error
A character that is not a legal header separator was
encountered while parsing the header; for example,
no space followed the header, thus ∗GMC"MACRO"
is an error.
Program mnemonic The header contains more than 12 characters (see
too long
–112
–113
IEEE-488.2, 7.6.1.4.1).
Undefined header
The header is syntactically correct, but it is unde-
fined for this specific counter; for example, ∗XYZ is
not defined for any device.
Header suffix out of Indicates that a non-header character has been en-
range
–114
–120
countered in what the parser expects is a header el-
ement.
Numeric data error This error, as well as errors –121 through –129, are
generated when parsing a data element that ap-
pears to be of a numeric type. This particular error
message is used when the counter cannot detect a
more specific error.
Numeric data error;
overflow from con-
version
Numeric data error;
underflow from con-
version
Numeric data error;
not a number from
conversion
Error Code -105 to -120 8-3
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Error Messages
Command Errors
Error
Number
Error Description Description/Explanation/Examples
Invalid character in An invalid character for the data type being parsed
number
–121
was encountered; for example, an alpha in a deci-
mal numeric or a “0" in octal data.
Exponent too large The magnitude of the exponent was larger than
32000 (see IEEE-488.2, 7.7.2.4.1).
–123
–124
Too many digits
The mantissa of a decimal numeric data element con-
tained more than 255 digits excluding leading zeros
(see IEEE-488.2, 7.7.2.4.1).
Numeric data not al- A legal numeric data element was received, but the
lowed
–128
–130
counter does not accept it in this position for the
header.
Suffix error
This error as well as errors –131 through –139 is
generated when parsing a suffix. This particular er-
ror message is used when the counter cannot detect
a more specific error.
Invalid suffix
The suffix does not follow the syntax described in
IEEE-488.2, 7.7.3.2, or the suffix is inappropriate for
this counter.
–131
Suffix too long
The suffix contained more than 12 characters (see
IEEE-488.2, 7.7.3.4).
–134
–138
–140
Suffix not allowed
A suffix was encountered after a numeric element
that does not allow suffixes.
Character data error This error as well as errors 141 through –149 is gener-
ated when parsing a character data element. This par-
ticular error message is used when the counter cannot
detect a more specific error.
Invalid character
data
Either the character data element contains an invalid
character or the particular element received is not
valid for the header.
–141
Character data too The character data element contains more than 12
long characters (see IEEE-488.2, 7.7.1.4).
Character data not A legal character data element was encountered
–144
–148
–150
allowed
where prohibited by the counter.
String data error
This error as well as errors –151 through –159 is gen-
erated when parsing a string data element. This partic-
ular error message is used when the counter cannot
detect a more specific error.
8-4 Error Code -121 to -150
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Error Messages
Command Errors
Error
Number
Error Description Description/Explanation/Examples
Invalid string data
Invalid string data;
unexpected end of
message
A string data element was expected, but was invalid
for some reason (see IEEE-488.2, 7.7.5.2); for ex-
ample, an END message was received before the
terminal quote character.
–151
String data not al-
lowed
A string data element was encountered but was not al-
lowed by PM6685 at this point in parsing.
This error as well as errors –161 through –169 is
generated when parsing a block data element. This
particular error message is used when PM6685 can-
not detect a more specific error.
–158
–160
Block data error
Invalid block data
A block data element was expected, but was invalid
for some reason (see IEEE-488.2, 7.7.6.2); for ex-
ample, an END message was received before the
length was satisfied.
–161
Block data not al-
lowed
A legal block data element was encountered but
was not allowed by the counter at this point in pars-
ing.
–168
–170
Expression data er- This error as well as errors –171 through –179 is
ror
generated when parsing an expression data ele-
ment. This particular error message is used if the
counter cannot detect a more specific error.
Expression data er- The floating-point operations specified in the expres-
ror; floating-point
underflow
sion caused a floating-point error.
Expression data er-
ror; floating-point
overflow
Expression data er-
ror; not a number
Expression data er- Two channel list specifications, giving primary and
ror; different number secondary channels for 2-channel measurements,
of channels given
contained a different number of channels.
Error Code -151 to -170 8-5
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Error Messages
Command Errors
Error Description Description/Explanation/Examples
Error
Number
Invalid expression
data
The expression data element was invalid (see
IEEE-488.2, 7.7.7.2); for example, unmatched pa-
rentheses or an illegal character were used.
A mnemonic data element in the expression was not
–171
Invalid expression
data; bad mnemonic valid.
Invalid expression The expression contained a hexadecimal element
data; illegal element not permitted in expressions.
Invalid expression
data; unexpected
end of message
Invalid expression
data; unrecognized
expression type
End of message occurred before the closing paren-
thesis.
The expression could not be recognized as either a
mathematical expression, a data element list or a
channel list.
Expression data not A legal expression data was encountered but was
–178
–180
allowed
not allowed by the counter at this point in parsing.
This error as well as errors –181 through –189 is
generated when defining a macro or executing a
macro. This particular error message is used when
the counter cannot detect a more specific error.
Indicates that a macro parameter placeholder
($<number) was encountered outside of a macro
definition.
Macro error
Invalid outside
macro definition
–181
–183
–184
Invalid inside macro Indicates that the program message unit sequence,
definition
sent with a ∗DDT or ∗DMC command, is syntacti-
cally invalid (see IEEE-10.7.6.3).
Macro parameter
error
Indicates that a command inside the macro defini-
tion had the wrong number or type of parameters.
The parameter numbers given are not continuous;
one or more numbers have been skipped.
Macro parameter
error; unused pa-
rameter
Macro parameter er- The’$’ sign was not followed by a single digit be-
ror; badly formed
placeholder
tween 1 and 9.
Macro parameter
error; parameter
count mismatch
The macro was invoked with a different number of
parameters than used in the definition.
8-6 Error Code -171 to -184
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Error Messages
Execution errors
Error
Number
Error Description description/explanation/examples
Execution error
This is the generic syntax error for devices that can-
not detect more specific errors. This code indicates
only that an Execution Error as defined in
IEEE-488.2, 11.5.1.1.5 has occurred.
–200
Trigger error
–210
–211
Trigger ignored
Indicates that a GET, ∗TRG, or triggering signal was
received and recognized by the counter but was ig-
nored because of counter timing considerations; for
example, the counter was not ready to respond.
Indicates that an arming signal was received and
recognized by the counter but was ignored.
Indicates that a request for a measurement initiation
was ignored because another measurement was al-
ready in progress.
Arm ignored
Init ignored
–212
–213
Trigger deadlock
Arm deadlock
Indicates that the trigger source for the initiation of a
measurement is set to GET and subsequent mea-
surement query is received. The measurement can-
not be started until a GET is received, but the GET
would cause an INTERRUPTED error.
–214
–215
Indicates that the arm source for the initiation of a
measurement is set to GET and subsequent mea-
surement query is received. The measurement can-
not be started until a GET is received, but the GET
would cause an INTERRUPTED error.
Parameter error
Indicates that a program-data-element related error
occurred. This error message is used when the
counter cannot detect the more specific errors –221
to –229.
–220
–221
Settings conflict
Settings conflict;
PUD memory is
protected
Indicates that a legal program data element was
parsed but could not be executed due to the current
counter state (see IEEE-488.2, 6.4.5.3 and
11.5.1.1.5.)
Settings conflict; in-
valid combination of
channel and function
Error Code -200 to -221 8-7
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Error Messages
Execution errors
Error Description description/explanation/examples
Data out of range Indicates that a legal program data element was
Error
Number
–222
parsed but could not be executed because the inter-
preted value was outside the legal range as defined
by the counter (see IEEE-488.2, 11.5.1.1.5.).
Data out of range; The expression was too large for the internal float-
exponent too large ing-point format.
Data out of range; Data below minimum for this function/parameter.
below minimum
Data out of range; Data above maximum for this function/ parameter.
above maximum
Data out of range; A number outside 0 to 19 was given for the save/re-
(Save/recall mem- call memory.
ory number)
Too much data
Too much data;
∗PUD string too
long
Indicates that a legal program data element of block,
expression, or string type received that contained
more data than the counter could handle due to
memory or related counter-specific requirements.
–223
Too much
data;String or block
too long
Illegal parameter
value
Used where exact value, from a list of possible val-
ues, was expected.
–224
–230
–231
Data corrupt or
stale
Possibly invalid data; new reading started but not
completed since last access.
Data questionable
Data questionable;
One or more data elements sent with a MEASure or
one or more data el- CONFigure command was ignored by the counter.
ements ignored
Hardware error
Indicates that a legal program command or query
could not be executed because of a hardware prob-
lem in the counter. Definition of what constitutes a
hardware problem is completely device specific. This
error message is used when the counter cannot de-
tect the more specific errors described for errors
–241 through –249.
–240
8-8 Error Code -222 to -240
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Error Messages
Execution errors
Error
Number
Error Description description/explanation/examples
Hardware missing
Hardware missing;
(prescaler)"
Indicates that a legal program command or query
–241
–254
–258
could not be executed because of missing counter
hardware; for example, an option was not installed.
Definition of what constitutes missing hardware is com-
pletely device specific.
Media full
Indicates that a legal program command or query
could not be executed because the media was full;
for example, there is no room on the disk. The defi-
nition of what constitutes a full media is device spe-
cific.
Media protected
Expression error
Indicates that a legal program command or query
could not be executed because the media was pro-
tected; for example, the write-protect tab on a disk
was present. The definition of what constitutes pro-
tected media is device specific.
Indicates that an expression-program data-element-
related error occurred. This error message is used
when the counter cannot detect the more specific
errors described for errors –261 through –269.
Indicates that a syntactically correct expression pro-
gram data element could not be executed due to a
math error; for example, a divide-by-zero was at-
tempted.
–260
–261
–270
Math error in ex-
pression
Macro error
Indicates that a macro-related execution error oc-
curred. This error message is used when the counter
cannot detect the more specific error described for er-
rors –271 through –279.
Macro error; out of No room for any more macro names.
name space
Macro error; out of No room for this macro definition.
definition space
Macro syntax error Indicates that a syntactically correct macro program
data sequence, according to IEEE-488.2 10.7.2,
could not be executed due to a syntax error within
the macro definition (see IEEE-488.2, 10.7.6.3)
Macro execution er- Indicates that a syntactically correct macro program
–271
–272
ror
data sequence could not be executed due to some
error in the macro definition (see IEEE-488.2,
10.7.6.3)
Error Code -241 to -272 8-9
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Error Messages
Execution errors
Error
Number
Error Description description/explanation/examples
Illegal macro label
Indicates that the macro label defined in the ∗DMC
–273
command was a legal string syntax, but could not be
accepted by the counter (see IEEE-488.2, 10.7.3 and
10.7.6.2); for example, the label was too long, the same
as a common command header, or contained invalid
header syntax.
Macro parameter
error
Indicates that the macro definition improperly used a
macro parameter place holder (see IEEE-488.2,
10.7.3).
–274
–275
Macro definition too Indicates that a syntactically correct macro program
long
data sequence could not be executed because the
string or block contents were too long for the coun-
ter to handle (see IEEE-488.2, 10.7.6.1).
Macro recursion er- Indicates that a syntactically correct macro program
–276
–277
–278
ror
data sequence could not be executed because the
counter found it to be recursive (see IEEE-488.2,
10.7.6.6).
Macro redefinition
not allowed
Indicates that a syntactically correct macro label in
the ∗DMC command could not be executed because
the macro label was already defined (see
IEEE-488.2, 10.7.6.4).
Macro header not
found
Indicates that a syntactically correct macro label in
the ∗GMC? query could not be executed because
the header was not previously defined.
8-10 Error Code -273 to -278
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Error Messages
Standardized Device specific errors
Error
Number
Error Description description/explanation/examples
Device specific error This code indicates only that a Device-Dependent
Error as defined in IEEE-488.2, 11.5.1.1.6 has oc-
curred. Contact your local service center.
–300
Memory error
Indicates that an error was detected in the counter’s
memory. Contact your local service center.
Indicates that the protected user data saved by the
∗PUD command has been lost. Contact your local
service center.
–311
–312
PUD memory lost
Save/recall memory Indicates that the nonvolatile calibration data used
lost
–314
by the ∗SAV? command has been lost. Contact your
local service center.
Self-test failed
Contact your local service center.
–330
–350
Queue overflow
A specific code entered into the queue in lieu of the
code that caused the error. This code indicates that
there is no room in the queue and an error occurred
but was not recorded.
Error Code -300 to -350 8-11
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Error Messages
Query errors
Error Description description/explanation/examples
Error
Number
Query error
This code indicates only that a Query Error as de-
fined in IEEE-488.2, 11.5.1.1.7 and 6.3 has oc-
curred.
–400
Query
INTERRUPTED
Indicates that a condition causing an INTER-
RUPTED Query error occurred (see IEEE-488.2,
6.3.2.3); for example, a query was followed by DAB
or GET before a response was completely sent.
The additional information indicates the IEEE-488.2
message exchange state where the error occurred.
–410
Query INTER-
RUPTED; in send
state
Query INTER-
RUPTED; in query
state
Query INTER-
RUPTED; in re-
sponse state
Query
Indicates that a condition causing an
–420
UNTERMINATED
UNTERMINATED Query error occurred (see
IEEE-488.2, 6.3.2.2); for example, the counter was
addressed to talk and an incomplete program mes-
sage was received.
Query The additional information indicates the IEEE-488.2
UNTERMINATED; message exchange state where the error occurred
in idle state
Query
UNTERMINATED;
in read state
Query
UNTERMINATED;
in send state
Query
DEADLOCKED
Indicates that a condition causing an DEADLOCKED
Query error occurred (see IEEE-488.2, 6.3.1.7); for
example, both input buffer and output buffer are full
and the counter cannot continue.
–430
–440
Query
Indicates that a query was received in the same pro-
gram message after an query requesting an indefi-
nite response was executed (see IEEE-488.2,
6.5.7.5.7.)
UNTERMINATED
after indefinite re-
sponse
8-12 Error Code -400 to -440
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Error Messages
CNT-8X Device specific errors (leading 1 only for PM6681)
Error Description description/explanation/examples
Error
Number
Device operation
gave floating-point eration.
underflow
A floating-point error occurred during a counter op-
(1)100
(1)101
(1)102
Device operation
gave floating-point eration.
overflow
A floating-point error occurred during a counter op-
Device operation A floating-point error occurred during a counter op-
gave ‘not a number’ eration.
Invalid measure-
ment function
The counter was requested to set a measurement
function it could not make.
(1)110
(1)120
(1)130
(1)131
(1)132
(1)133
(1)134
(1)135
(1)136
Save/recall memory An attempt was made to write in a protected mem-
protected ory.
Unsupported com- Indicates a mismatch between bus and counter ca-
mand
pabilities.
Unsupported
boolean command
Unsupported deci-
mal command
Unsupported enu-
merated command
Unsupported auto
command
Unsupported single
shot command
Command queue
The counter has an internal command queue with
full; last command room for about 100 commands. A large number of
discarded
commands arrived fast without any intervening
query.
Inappropriate suffix A suffix unit was not appropriate for the command.
Recognized units are Hz (Hertz), s (seconds), Ohm
(1)137
(1)138
(1)139
unit
(Ω) and V (Volt).
A command reached counter execution which
Unexpected com-
mand to device exe- should have been handled by the bus.
cution
Unexpected query A query reached counter execution which should
to device execution
have been handled by the bus.
Error Code (1)100 to -(1)139 8-13
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Error Messages
CNT-8X Device specific errors (leading 1 only for PM6681)
Error Description description/explanation/examples
Error
Number
Bad math expres-
sion format
Only a fixed, specific math expression is recognized
by the counter, and this was not it.
(1)150
(1)160
(1)170
(1)190
(1)191
Measurement bro- A new bus command caused a running measure-
ment to be broken off.
ken off
Instrument set to
default
An internal setting inconsistency caused the instru-
ment to go to default setting.
Error during calibra- An error has occurred during calibration of the in-
tion strument.
Hysteresis calibra- The input hysteresis values found by the calibration
tion failed
routine was out of range. Did you remember to re-
move the input signal?
Message exchange An error occurred in the message exchange handler
error (generic error).
Reset during bus in- The instrument was waiting for more bus input, but
(1)200
(1)201
(1)202
(1)203
(1)204
put
the waiting was broken by the operator.
Reset during bus
output
The instrument was waiting for more bus output to be
read, but the waiting was broken by the operator.
An internal error in the message exchange handler.
Bad message ex-
change control state
Unexpected reason A spurious GPIB interrupt occurred, not conforming
for GPIB interrupt
to any valid reason like an incoming byte, address
change, etc.
No listener on bus This error is generated when the counter is an ac-
when trying to re-
spond
(1)205
tive talker, and tries to send a byte on the bus, but
there are no active listeners.
(This may occur if the controller issues the device
talker address before its own listener address, which
some PC controller cards has been known to do)
Mnemonic table er- An abnormal condition occurred in connection with
(1)210
(1)211
(1)212
ror
the mnemonics tables (generic error).
The macro definitions have been corrupted (could
be loss of memory).
Wrong macro table
checksum found
Wrong hash table
checksum found
The hash table has been corrupted. Could be bad
memory chips or address logic. Contact your local
service center.
RAM failure to hold The memory did not retain information written to it.
information (hash
table)
(1)213
Could be bad memory chips or address logic. Con-
tact your local service center.
8-14 Error Code (1)150 to -(1)213
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Error Messages
CNT-8X Device specific errors (leading 1 only for PM6681)
Error
Number
Error Description description/explanation/examples
Hash table overflow The hash table was too small to hold all mnemon-
ics. Ordinarily indicates a failure to read (RAM or
ROM) correctly. Contact your local service center.
(1)214
Parser error
Generic error in the parser.
(1)220
(1)221
(1)222
Illegal parser call
The parser was called when it should not be active.
Unrecognized input A character not in the valid IEEE488.2 character set
character was part of a command.
Internal parser error The parser reached an unexpected internal state.
(1)223
(1)230
Response formatter Generic error in the response formatter.
error
Bad response for-
matter call
The response formatter was called when it should
not be active.
(1)231
(1)232
(1)233
Bad response for-
matter call (eom)
Invalid function
code to response
formatter
The response formatter was called to output an end
of message, when it should not be active.
The response formatter was requested to output
data for an unrecognized function.
Invalid header type The response formatter was called with bad data for
to response format- the response header (normally empty)
ter
(1)234
Invalid data type to The response formatter was called with bad data for
response formatter the response data.
(1)235
(1)240
Unrecognized error An error number was found in the error queue for
number in error
queue
which no matching error information was found.
See also Error Messages in Appendix 1 of the Operators Manual.
Error Code (1)214 to -(1)240 8-15
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Error Messages
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8-16 Error Code
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Chapter 9
Command Reference
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9-2 Command Reference
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:ABORt
PM6680B/81/85
Abort Measurement
The ABORt command terminates a measurement. The trigger subsystem state is
set to “idle-state”.
Type of command:
Aborts all previous measurements if *WAI is not used.
Complies to standards:
SCPI 1991.0, confirmed.
9-4 Command Reference
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Arming Subsystem
:ARM
[ :STARt / :SEQuence [ 1 ] ]
:LAYer2
:[ IMMediate ]
:SOURce
[ :LAYer [ 1 ] ]
8
8
BUS | IMMediate
:COUNt
:DELay
:ECOunt
:SLOPe
:SOURce
<Numeric value> | MIN | MAX
8
<Numeric value> | MIN | MAX
POSitive|NEGative
EXTernal2 | External4 | IMMediate
<Numeric value> | MIN | MAX
8
8
8
:STOP / SEQuence2
[ :LAYer [ 1 ] ]
:DELay
8
<Numeric value> | MIN | MAX
PM6681)
(Only PM6680B /
:ECOunt
:SLOPe
:SOURce
8
8
8
<Numeric value> | MIN | MAX
POSitive | NEGative
EXTernal2 | EXTernal4 | IMMediate | TIMerf
(Only PM6680B / PM6681)
Command Reference 9-5
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:ARM :COUNt
PM6680B/81/85
8«<Numeric value>|MIN|MAX»
No. of Measurements on each Bus arm
This count variable controls the upward exit of the “wait-for-bus-arm” state
(:ARM:STARt:LAY1). The counter loops the trigger subsystem downwards
COUNt number of times before it exits to the idle state.
This means that a COUNt No. of measurements can be done for each Bus arming
or INITiate.
The actual number of measurements made on each INIT is equal to:
(:ARM:START:COUNT)*(:TRIG:START:COUNT)
L
Parameters:
<Numeric value> is a number between 1 and 65 535. (1 switches the function OFF.)
MIN gives 1
MAX gives 65 535
Returned format: <Numeric value>¿
Example:
SEND® :ARM:COUN8100¿
*RST condition:
1
Complies to standards:
SCPI 1991.0, confirmed
9-6 Command Reference
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PM6680B/81/85
:ARM :DELay
8 «<Numeric value> | MIN | MAX»
Delay after External Start Arming
This command sets a delay between the pulse on the arm input and the time when
the counter starts measuring. The delay is only active when the following is se-
lected:
:ARM:STARt:SOURce 8 EXT4.
Range: 200 ns to 1.67 s.
The optional node [:FIXed] is only accepted by PM6681.
+
<Numeric value> is a number between 200*10–9 and 1.67s.
Parameters:
MIN gives 0 which switches the delay OFF.
MAX gives 1.67 s
Returned format: <Numeric value>¿
Example:
SEND® :ARM:DEL 80.1¿
*RST condition:
0
Complies to standards:
SCPI 1991.0, confirmed.
PM6680B PM6681
:ARM :ECOunt
8 «<Numeric value> | MIN | MAX»
External Events before Start Arming
This command sets the number of negative edges required on the B-input (EXT2)
before the counter starts measuring (Start Arming Delay by events). Start Arming
delay by events cannot be used at the same time as stop Arming delay by events
(:ARM:STOP:ECO).
The delay is only active when :ARM:START:SOUR 8EXT2|EXT4 is selected.
+
Only one of the delays: :ARM:STAR:DEL, :ARM:STOP:DEL,
:ARM:STAR:ECO, and :ARM:STOP:ECO can be used at a time. When you pro-
gram this delay, the other three delays will be reset to their *RST values.
Parameters:
<Numeric value> is a number between 2 and 16 777 215. 1 switches the delay by events OFF.
SEND® :ARM:ECO 825¿
Returned format: <Numeric value>¿
*RST condition:
1
Complies to standards:
SCPI 1991.0, confirmed.
Command Reference 9-7
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:ARM :LAYer2
PM6680B/81/85
Bus Arming Override
This command overrides the waiting for bus arm, provided the source is set to bus.
When this command is issued, the counter will immediately exit the “wait-for-bus-
arm” state.
The counter generates an error if it receives this command when the trigger sub-
system is not in the “wait-for-bus-arm” state.
If the Arming source is set to Immediate, this command is ignored.
Example:
SEND® :ARM:LAY2¿
Complies to standards:
SCPI 1991.0, confirmed.
:ARM :LAYer2 :SOURce
PM6680B/81/85
8 «BUS | IMMediate»
Bus Arming On/Off
Switches between Bus and Immediate mode for the “wait-for-bus-arm” function,
(layer 2). GET and *TRG triggers the counter if Bus is selected as source.
If the counter receives GET/ *TRG when not in “wait-for-bus-arm” state, it ignores
the trigger and generates an error.
It also generates an error if it receives GET/ *TRG and bus arming is switched off
(set to IMMediate).
Returned format: BUS|IMM¿
Example:
SEND® :ARM:LAY2:SOUR 8 BUS¿
Complies to standards:
SCPI 1991.0, confirmed.
9-8 Command Reference
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PM6680B/81/85
:ARM :SLOPe
8 «POSitive|NEGative»
External Arming Start Slope
Sets the slope for the start arming condition.
Returned format: POS|NEG¿
Example:
SEND® :ARM:SLOP 8 NEG¿
*RST condition: POS
Complies to standards:
SCPI 1991.0, confirmed.
PM6680B/81/85
:ARM :SOURce
8 «EXTernal2 | EXTernal4 | IMMediate»
External Arming Start Source
Selects channel 4 (Input E) as arming input, or switches off the start arming func-
tion. When switched off the DELay is inactive.
Parameters:
EXTernal2 is input B
(Only PM6680B/81)
EXTernal4 is input E
IMMediate is Start arming OFF
Returned format: EXT2 | EXT4 | IMM¿
Example:
SEND® :ARM:SOUR 8 EXT4¿
*RST condition: IMM
Complies to standards:
SCPI 1991.0, confirmed.
Command Reference 9-9
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:ARM :STOP :DELay
PM6680B PM6681
8 «<Numeric value> | MIN | MAX»
Delay after External Stop Arming
This command sets a delay between stop slope of the pulse on the arm input and
the time when the counter stops measuring. The delay is only active when the fol-
lowing is selected:
:ARM:STOP:SOURce 8 EXT2|EXT4.
Range: 200 ns to 1.67 s.
The optional node [:FIXed] is only accepted by PM6681.
+
<Numeric value> is a number between 200*10–9 and 1.67s.
Parameters:
MIN gives 0 which switches the delay OFF.
MAX gives 1.67 s
Returned format: <Numeric value>¿
Example:
SEND® :ARM:STOP:DEL 8 0.1¿
*RST condition:
0
Complies to standards:
SCPI 1991.0, confirmed.
:ARM :STOP :ECOunt
PM6680B/81/85
8 «<Numeric value> | MIN | MAX»
External Events before Stop Arming
This command sets the number of stop slopes are required on the external stop
arming source before the counter stop measuring (Stop Arming Delay by events).
Stop Arming delay by events cannot be used at the same time as start Arming de-
lay by events (:ARM:START:ECO).
The delay is only active when :ARM:STOP:SOUR EXT2|EXT4 is selected.
+
Only one of the delays: :ARM:STAR:DEL, :ARM:STOP:DEL,
:ARM:STAR:ECO, and :ARM:STOP:ECO can be used at a time. When you pro-
gram this delay, the other three delays will be reset to their *RST values.
Parameters:
<Numeric value> is a number between 2 and 16 777 215. 1 switches the delay by events OFF.
SEND® :ARM:STOP:ECO 8 25¿
Returned format: <Numeric value>¿
*RST condition:
1
Complies to standards:
SCPI 1991.0, confirmed.
9-10 Command Reference
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PM6680B/81/85
:ARM :STOP :SLOPe
8 «POSitive | NEGative»
External Stop Arming Slope
Sets the slope for the stop arming condition.
Returned format: POS|NEG¿
Example:
SEND® :ARM:STOP:SLOP 8 NEG¿
*RST condition: POS
Complies to standards:
SCPI 1991.0, confirmed.
PM6680B/81/85
:ARM :STOP :SOURce
8 «EXTernal2 | EXTernal4 | IMMediate»
External Stop Arming Source
Selects between channel 2 (Input B) and channel 4 (Input E) as stop arming input,
or switches off the stop arming function.
Parameters:
EXTernal2 is input B
(Only PM6680B/81)
EXTernal4 is input E
IMMediate is Stop arming OFF
Returned format: EXT4|IMM¿
Example:
SEND® :ARM:STOP:SOUR 8 EXT4¿
*RST condition: IMM
Complies to standards:
SCPI 1991.0, confirmed.
Command Reference 9-11
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Calculate Subsystem
:CALCulate
:STATe
:DATA?
8
ON|OFF
:IMMediate
:MATH
[:EXPRession]
:STATe
:AVERage
8
<Numeric expression>
ON|OFF
8
[:STATe]
:TYPE
:COUNt
8
8
ON|OFF
8 MIN|MAX|SDEViation|MEAN
<Numeric value>|MIN|MAX
:LIMit
[:STATe] 8 ON|OFF
:UPPer
[:DATA]
:STATe
8
8
<Numeric value>|MIN|MAX
ON|OFF
8
:LOWer
[:DATA]
:STATe
<Numeric value>|MIN|MAX
ON|OFF
8
:FAIL?
Command Reference 9-13
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:CALCulate :AVERage :COUNt
PM6680B PM6681
8 < No. of samples>
Sample Size for Statistics
Sets the number of samples to use in statistics sampling.
Parameters: <No. of samples> is a number in the range of 1 to 65535.
Returned format: < No. of samples>¿
*RST condition: 100
:CALCulate :AVERage :STATe
PM6680B PM6681
8 < Boolean >
Enable Statistics
Switches On/Off the statistical function. Note that the CALCulate subsystem is au-
tomatically enabled when the statistical functions are switched on. This means that
other enabled calculate sub-blocks are indirectly switched on. The statistics must
be enabled before the measurements are performed. When the statistical function
is enabled, the counter will keep the trigger subsystem initiated until the
:CALC:AVER:COUNT variable is reached. This is done without any change in the
trigger subsystem settings. Consider that the trigger subsystem is programmed to
perform 1000 measurements when initiated. In such a case, the counter must
make 10000 measurements if the statistical function requires 9500 measurements
because the number of measurements must be a multiple of the number of mea-
surements programmed in trigger subsystem (1000 in this example).
Parameters
<Boolean> = ( 1/ON | 0/OFF )
Returned format: <1|0¿
*RST condition: OFF
9-14 Command Reference
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PM6680B PM6681
:CALCulate :AVERage :TYPE
8 «MAX|MIN|MEAN|SDEViation»
Statistical Type
Selects the statistical function to be performed.
You must use :CALC:DATA? to read the result of statistical operations. :READ?,
:FETC? will only send the results that the statistical operation is based on.
+
Parameters:
MAX returns the maximum value of all samples taken under :CALC:AVER
control.
MIN returns the minimum value of all samples taken under :CALC:AVER control.
n
1
MEAN returns the mean value of the samples taken: x =
X
i
å
n
i =1
2
æ
ö
÷
ø
1
1
SDEV Returns the standard deviation: s =
X 2
-
X
i
ç
è å
å
i
(
)
n - 1
n
Returned format: MAX|MIN|MEAN|SDEV¿
*RST condition: MEAN
PM6680B/81/85
:CALCulate :DATA?
Fetch calculated data
Fetches data calculated in the post processing block. Use this command to fetch
the calculated result without making a new measurement.
Returned Format:
<Decimal data>¿
Example for PM6685:
SEND® :CALC:MATH:STAT 8 ON;:CALC:MATH 8 (X 8 - 8 10.7E6);:INIT;
*OPC
Wait for operation complete
SEND® :CALC:DATA?
READ¬ <Measurement 8 result 8 minus 8 10.7E6>
Example for PM6680B/81
SEND® :CALC:MATH:STAT8ON;:CALC:MATH8(((18*8X)8-810.7E6)8/81)
;:init; *OPC
Wait for operation complete
SEND® :CALC:DATA?
READ¬ <Measurement 8 result 8 minus 8 10.7E6>
*RST condition:
Event, no *RST condition.
Complies to standards:
SCPI 1991.0, Confirmed
Command Reference 9-15
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:CALCulate :IMMediate
PM6680B/81/85
Recalculate Data
This event causes the calculate subsystem to reprocess the statistical function on
the sense data without reacquiring the data. Query returns this reprocessed data.
This command is not very useful in PM6685, but is accepted to maintain com-
patibility with the other counters in the CNT-8X series of counters.
+
Returned format: <Decimal data>¿
Where: <Decimal data> is the recalculated data.
Example:
SEND® :CALC:AVER:STAT 8 ON;TYPE 8 SDEV;:INIT;*OPC
Wait for operation complete
SEND® :CALC:DATA?
READ¬ <Value 8 of 8 standard 8 deviation>
SEND® :CALC:AVER:TYPE 8 MEAN
SEND® :CALC:IMM?
READ¬ <Mean 8 value>
*RST condition: Event, no *RST condition.
Complies to standards:
SCPI 1991.0, Confirmed.
:CALCulate :LIMit
PM6680B/81/85
8 <Boolean>
Enable Monitoring of Parameter Limits
Turns On/Off the limit-monitoring calculations.
Limit monitoring makes it is possible to get a service request when the measure-
ment value falls below a lower limit, or rises above an upper limit.
Two status bits are defined to support limit-monitoring. One is set when the results
are greater than the UPPer limit, the other is set when the result is less than the
LOWer limit. The bits are enabled using the standard *SRE command and
:STAT:DREG0:ENAB. Using both these bits, it is possible to get a service request
when a value passes out of a band ( UPPer is set at the upper band border and
LOWer at the lower border) OR when a measurement value enters a band (LOWer
set at the upper band border and UPPer set at the lower border).
Turning the limit-monitoring calculations On/Off will not influence the status regis-
ter mask bits, which determine whether or not a service request will be generated
when a limit is reached. Note that the calculate subsystem is automatically en-
abled when limit-monitoring is switched on. This means that other enabled calcu-
late sub-blocks are indirectly switched on.
Parameters <Boolean> = ( 1/ON | 0/OFF )
Returned format: 1|0¿
*RST condition: OFF
Complies to standards:
SCPI 1991.0, confirmed.
9-16 Command Reference
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PM6680B/81/85
:CALCulate :LIMit :FAIL?
Limit Fail
Returns a 1 if the limit testing has failed (the measurement result has passed the
limit), and a 0 if the limit testing has passed.
The following events reset the fail flag:
– Power-on
– *RST
– A :CALC:LIM:STAT OFF ® :CALC:LIM:STAT 8 ON transition
– Reading a 1 with this command.
Returned format: 1| 0¿
Example:
SEND® SENS:FUNC 8 FREQ;:CALC:LIM:STAT 8 ON;:CALC:LIM 8 :HIGH8
1E3;READ?;*WAI;:CALC:LIM:FAIL?
READ¬ 1
if frequency ia above 1kHz, otherwize 0
Complies to standards:
SCPI 1991.0, confirmed.
PM6680B/81/85
:CALCulate :LIMit :LOWer
8 «<Decimal data>|MAX|MIN»
Set Low Limit
Sets the value of the ‘Lower Limit’ , i.e., the lowest measurement result allowed be-
fore the counter generates a 1 that can be read with :CALCulate:LIMit:FAIL?,
or by reading the corresponding status byte.
Parameters
Parameter range: –9.9*10+37 to +9.9*10+37
.
Returned format: < Decimal data>¿
*RST condition:
0
Complies to standards:
SCPI 1991.0, confirmed.
Command Reference 9-17
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:CALCulate :LIMit :LOWer :STATe
PM6680B/81/85
8 <Boolean>
Check Against Lower Limit
Selects if the measured value should be checked against the lower limit.
Parameters <Boolean> = ( 1/ON | 0/OFF )
Returned format: 1| 0 ¿
*RST condition:
0
Complies to standards:
SCPI 1991.0 confirmed.
:CALCulate :LIMit :UPPer
PM6680B/81/85
8 «<Decimal data>|MAX|MIN»
Set Upper Limit
Sets the value of the ‘Upper Limit’, i.e., the highest measurement result allowed
before the counter generates a 1 that can be read with :CALCu-
late:LIMit:FAIL?, or by reading the corresponding status byte.
Parameters
Range: –9.9*10+37 to +9.9*10+37
Returned format: <Decimal data>¿
*RST condition:
0
Complies to standards:
SCPI 1991.0, confirmed.
9-18 Command Reference
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PM6680B/81/85
:CALCulate :LIMit :UPPer :STATe
8 <Boolean>
Check Against Upper Limit
Selects if the measured value should be checked against the upper limit.
Parameters <Boolean> = ( 1/ON | 0/OFF )
Returned format: 1| 0 ¿
*RST condition:
0
Complies to standards:
SCPI 1991.0, confirmed.
Command Reference 9-19
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:CALCulate :MATH
PM6685
8 (<expression>)
Select Mathematical Expression
Defines the mathematical expression used for mathematical operations. This func-
tion equals the nulling function from the front panel.
The data type <expression data> must be typed within parentheses.
+
+
Parameters
The operand must be surrounded by space characters.
<expression> is: (X + K) No deviations are allowed from this form.
K can be any positive or negative numerical constant within the range –9.9E+37 to
+9.9E+37
X is the measurement result.
Returned format: <expression>¿ Where <expression> is the expression selected.
Example This example subtracts 10700000 from the measurement result.
:CALC:MATH 8 (X 8 – 8 10.7E6)
SEND®
Example 2 This example defines the mathematical expression, enables postprocessing
and mathematics, make a measurement, and fetches the result:
:CALC:MATH 8 (X 8 - 8 10.7E6);MATH:STATE 8 ON;:READ?
SEND®
*RST condition: (X - 1.0000 E +7)
Complies to standards:
SCPI 1991.0 Confirmed.
9-20 Command Reference
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PM6680B PM6681
:CALCulate :MATH
8 (<expression>)
Select Mathematical Expression
Defines the mathematical expression used for mathematical operations. This func-
tion equals the nulling function from the front panel.
The data type <expression data> must be typed within parentheses.
+
Parameters
<expression> is one of the following two mathematical expressions:
((K8*_X)8+8L)8/8M or ((K8/8X)8+8L)8/8M No deviations are allowed.
K, L and M can be any positive or negative numerical constant, or use XOLD for the
last, previously measured value.
Each operand must be surrounded by space characters.
Example
:CALC:MATH 8 (((1 8 * 8 X) 8 – 8 0) 8 / 8 XOLD)
SEND®
This example gives a relative result from the last measuring result.
*RST condition:
((( 1* X ) + 0 ) 1) (No calculation)
Returned format: <expression>¿
Complies to standards:
SCPI 1991.0 Confirmed.
PM6680B/81/85
:CALCulate :MATH :STATe
8 <Boolean>
Enable Mathematics
Switches on/off the mathematical function. Note that the CALCulate subsystem is
automatically enabled when MATH operations are switched on. This means that
other enabled calculate sub-blocks are indirectly switched on. Switching off mathe-
matics, however, does not switch off the CALCulate subsystem.
Parameters:
<Boolean> = ( 1/ON | 0/OFF )
Returned syntax: 0|1
Example
:CALC:MATH:STAT 8 1
SEND®
This example switches on mathematics.
*RST condition: OFF
Complies to standards:
SCPI 1991.0, confirmed.
Command Reference 9-21
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:CALCulate :STATe
PM6680B/81/85
8 <Boolean>
Enable Calculation
Switches on/off the complete post-processing block. If disabled, neither mathemat-
ics or limit-monitoring can be done.
Parameter
<Boolean> = ( 1/ON | 0/OFF )
SEND® :CALC:STAT 8 1
Switches on Post Processing.
Returned format: 1|0¿
∗RST condition: OFF
Complies to standards:
SCPI 1991.0, Confirmed
9-22 Command Reference
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Calibration Subsystem
:CALibration
:INTerpolator
:AUTO
8
<Boolean>|ONCE
(Only PM6680B, PM6685)
PM6681 has factory calibrated interpolators, and calibration cannot be changed
by the operator.
Calibration of the PM6681 input hysteresis is done in the Diagnostis subsystem.
+
Command Reference 9-23
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:CALibration :INTerpolator :AUTO
PM6680B/85
8 <Boolean>| ONCE
Calibration of Interpolator
The PM6680B/85 are reciprocal counters that uses an interpolating technique to
increase the resolution. In time measurements, for example, interpolation in-
creases the resolution from 100 ns to 0.25 ns.
The counter calibrates the interpolators automatically once for every measurement
when this command is ON. When this command is OFF, the counter does no cali-
brations but uses the values from the last preceding calibration. The intention of
this command is to turn off the auto calibration for applications that dump mea-
surements into the internal memory. This will increase the measurement speed.
Parameters
<Boolean> = ( 1 | ON / 0 | OFF )
Returned format: 1|0¿
*RST condition: ON
See also:
9-24 Command Reference
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Configure Function
Set up Instrument for Measurement
:CONFigure
[:SCALar]<Measuring Function>
:ARRay<Measuring Function>
8
8
<Parameters>,(<Channels>)]
(<Array Size>)[,<Parameters>,(<Channels>)]
The array size for :MEASure and :CONFigure, and the channels, are expression
data that must be in parentheses ( ).
+
Measuring Function, Parameters and Channels are explained on page 9-54.
The counter uses the default Parameters and Channels when you omit them in
the command.
Command Reference 9-25
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:CONFigure :<Measuring Function>
PM6680B/81/85
[8 <parameters>[,(<channels>)]]
Configure the counter for a single measurement
Use the configure command instead of the measure query when you want to
change other settings, for instance, the input settings before making the measure-
ment and fetching the result.
The :CONFigure command controls the settings of the Input, Sense and Trigger sub-
systems in the counter in order to make the best possible measurement. It also
switches off any calculations with :CALC:STATE 8 OFF.
:READ? or :INITiate;:FETCh? will make the measurement and read the resulting
measured value.
Since you may not know exactly what settings the counter has chosen to configure
itself for the measurement, send an *RST before doing other manual set up mea-
surements.
Parameters
<Measuring Function>, <Parameters> and <Channels> are defined on page 9-54.
The optional parameter :SCALar means that one measurement is to be done.
Returned format: <String>¿
<String> contains the current measuring function and channel. The response is a
<String data element> containing the same answer as for [:SENSe]:FUNC-
tion?.
Example:
SEND® :CONF:FREQ:RAT8(@3),(@1)
Configures the counter for freq. ratio C/A.
Complies to standards:
SCPI 1991.0, confirmed.
9-26 Command Reference
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80B/81/85 :CONFigure :ARRay :<Measuring Function>
8 (<array size>)[,<parameters> [,(<channels>)]]
Configure the counter for an array of measurements
The :CONFigure:ARRay command differs from the :CONFigure command in
that it sets up the counter to perform the number of measurements you choose in
the <array size>.
To perform the selected function, you must trigger the counter with the :READ:AR-
Ray? or :INITiate;:FETCh:ARRay? queries.
Parameters <array size> sets the number of measurements in the array (1 to 2500).
<Measuring Function>, <Parameters>, and <Channels> are defined on page 9-54.
Example:
SEND® :CONF:ARR:PER 8 (7),5E–3,1E–6,(@4)
This example sets up the counter to make seven period measurements. The ex-
pected result is 5 ms, and the required resolution is 1 ms. The EXT ARM input is
the measuring input.
To make the measurements and fetch the seven measurement results:
SEND® :READ:ARR? 8 7
READ¬ 5.23421E-3,5.12311E-3,5.87526E-3, 8
5.50345E-3,5.33901E-3,5.25501E-3, 8 5.03571E-3
Complies to standards:
SCPI 1991.0, confirmed.
Command Reference 9-27
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:DIAGnostic:CALibration:INPut[1|2]:HYSTeresis 81
8 «OFF | ONCE»
Input comparator hysteresis calibration
These two commands measure and save the hysteresis levels of the input com-
parator. This makes it possible to achieve a trig level accuracy of 2.5 mV, which is
important in measurement functions such as phase, to get the best possible re-
sults.
Since the calibration compensates for the temperature drift of the input ampli-
fier, it should be made at the same temperature as the accurate measurement
is to be made at.
+
Before sending these commands, be sure to disconnect any signal leads from the
input connector of the input you want to calibrate.
If error code 1191 is generated, the calibration constants are out of range and you
must calibrate again. Check that no cables are connected to input A or input B be-
fore recalibrating.
When the input calibration procedure can be done without error codes, the calibra-
tion is correct.
Example:
SEND® :DIAG:CAL:INP:HYST 8 ONCE
This string calibrates both input A and input B.
Returned format:
OFF ¿
When queried, these commands always return OFF .
*RST condition: *RST does not affect these calibration data.
9-30 Command Reference
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:DISPlay :ENABle
PM6680B/81/85
8 < Boolean >
Display State
Turns On/Off the updating of the entire display section. This can be used for secu-
rity reasons or to improve the GPIB speed, since the display does not need to be
updated. Turning off the display reduces the dead time between measurements
by about 7 ms.
When the display is turned off, the information about the measurement resolution
is lost. That is, the counter will always send a full 12 digit mantissa independent of
the measurement resolution.
Parameters:
Where <Boolean> = (1 / ON | 0 / OFF)
Returned format:
1|0 ¿
*RST condition: ON
Complies to standards:
SCPI 1991.0, confirmed.
9-32 Command Reference
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:FETCh?
PM6680B/81/85
Fetch One Result
The fetch query retrieves one measuring result from the measurement result buffer
of the counter without making new measurements. Fetch does not work unless a
measurement has been made by the :INITiate, :MEASure?, or :READ? com-
mands.
If the counter has made an array of measurements, :FETCh? fetches the first
measuring results first. The second :FETCh? fetches the second result and so on.
When the last measuring result has been fetched, fetch starts over again with the
first result.
The same measuring result can be fetched again and again, as long as the result
is valid, i.e., until the following occurs:
– *RST is received.
– an :INITiate, 8 :MEASure or :READ command is executed
– any reconfiguration is done.
– an acquisition of a new reading is started.
If the measuring result in the output buffer is invalid but a new measurement has
been started, the fetch query completes when a new measuring result becomes
valid. If no new measurement has been started, an error is returned.
Where the optional :SCALar means that one result is retrieved.
Returned format: <data>¿
The format of the returned data is determined by the format commands :FORMat
and :FORMat:FIXed.
Complies to standards:
SCPI 1991.0, confirmed.
9-34 Command Reference
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PM6680B/81/85
:FETCh :ARRay?
8 «<fetch array size>|MAX»
Fetch an Array of Results
:FETCh:ARRay? query differs from the :FETCh? query by fetching several mea-
suring results at once.
An array of measurements must first be made by the commands. :INITiate,
:MEASure:ARRay? or :CONFigure:ARRay;:READ?
If the array size is set to a positive value, the first measurement made is the first
result to be fetched.
When the counter has made an array of measurements, :FETCh:ARRay? 8 10
fetches the first 10 measuring results from the output queue. The second
:FETCh:ARRay? 8 10 fetches the result 11 to 20, and so on. When the last mea-
suring result has been fetched, fetch:array starts over again with the first result.
In totalizing for instance, you may want to read the last measurement result in-
stead of the first one. This is possible if you set the array size to a negative num-
ber. Example: :FETCh:ARRay? 8 –5 fetches the last five results. The output
queue pointer is not altered when the array size is negative. That is, the example
above always gives the last five results every time the command is sent.
:FETCh:ARRay? 8 –1 is useful to fetch intermediate results in free-running or ar-
ray measurements without interrupting the measurement.
Parameters
:ARRay means that an array of retrievals are done for each :FETCh command.
<fetch array size> is the number of retrievals in the array. This number must not
exceed the number of measuring results in the measurement result buffer. The
<SIZE> parameter maximum limit is depending on the
:SENSe:INTernal:FORMat command as follows:
Array Size
PM6680B/85 PM6681
Format
Real:
Packed:
Measuring function
All functions
2048
2166
764
7019
6143
4466
4466
7019
8191
4095
Frequency, Period, Ratio Totalize
Pulse Width
Time-Interval, Rise/Fall time
Phase, Duty Cycle,Volt
Low resolution Frequency and Period
Low Res. Time-Interval and Pulse Width
MAX means that all the results in the output buffer will be fetched.
Command Reference 9-35
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Returned format: <data>[,<data>]¿
The format of the returned data is determined by the format commands :FORMat
and :FORMat:FIXed.
Example:
If :MEAS:ARR:FREQ? 8 (4) gives the results 1.1000,1.2000,1.3000,1.4000
:FETC:ARR 8 2 fetches the results 1.1000,1.2000
:FETC:ARR 8 2 once more fetches the results 1.3000,1.4000
:FETC:ARR 8 –1 always fetches the last result 1.4000
Complies to standards:
SCPI 1991.0, confirmed.
9-36 Command Reference
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:FORMat
PM6680B/85
8 «ASCii|REAL»
Response Data Type
Sets the format in which the result will be sent on the bus.
Parameters
ASCii will send the measurement result in ASCii form.<sign><mantissa value>E<sign><expo-
nent value>
<sign> = + or –
<mantissa value> = 1 to 12 digits (depending on
measuring resolution) plus one decimal point.
<exponent value> = 1 to 3 digits
REAL will send the result in binary IEEE Double Precision floating-point format in a
block-data element. #18<8 bytes real>. The <8 bytes real> is a double precision binary
floating-point response according to IEEE488.2/IEEE754. This means that the eight
bytes are sent in the following order:
First byte: <sign><7 MSB of the exponent>
Second byte: <4 LSB of the exponent><4 MSB of the fraction>
Third through eight byte: <48 LSB of the fraction>
Returned format: ASC|REAL¿
*RST condition: ASCii
Complies to standards:
SCPI 1991.0, confirmed.
:FORMat
PM6681
8 «ASCii|REAL»[, <Numeric value> | AUTO]
Response Data Type
Sets the format in which the result will be sent on the bus.
This command is identical to the above described command for the PM6680B/85,
except for the optional length parameter.
Parameters:
ASCii: The length controls the number of digits in the mantissa and may be set to values from
2 to 12 or AUTO.
AUTO: The length will be controlled by the resolution of each measurement result. Auto will be
ignored when :INTernal:FORMat 8 PACKed or
:DISPlay:ENABled 8 OFF is selected.
REAL: The length parameter is ignored, ‘reals’ are always output in 8 byte format.
Returned format: ASC|REAL, <Numeric value> | AUTO¿
*RST condition: ASCii, AUTO
See also: :FORMat :TINFormation command
Complies to standards:
SCPI 1991.0, confirmed.
9-38 Command Reference
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PM6680B/81/85
:FORMat :FIXed
8 <Boolean>
Response Data Format
Sets the ASCii format to fixed. This results in the following response format:
<sign><mantissa value>E<sign><exponent value>
Where:
<sign> = +|–
<mantissa value> = 12 digits plus one decimal point.
<exponent value> = 3 digits
Parameters <Boolean> = (1 / ON | 0 / OFF)
The counter will add leading zeroes when the measurement resolution is less
than 12 digits.
+
Returned format: 1|0 ¿
*RST condition: OFF
PM6681
:FORMat :SREGister
8 «ASCii | BINary | HEXadecimal | OCTal»
Data Type for Status Messages
This command selects the data type of the response to queries for any CONDition,
EVENt and ENABle register. This includes the IEEE 488.2 status register queries.
Parameters:
The data is transferred as ASCii bytes in NR1 format.
ASCii
The data is encoded as non-decimal numeric, base 16, pre-
ceded by ‘#H’ as specified in IEEE 488.2
HEXadecimal
The data is encoded as non-decimal numeric base 8, pre-
ceded by ‘#Q’ as specified in IEEE 488.2
OCTal
BINary
The data is encoded as non-decimal numeric, base 2, pre-
ceded by ‘#B’ as specified in IEEE 488.2
Returned format: ASCii | BINary | HEXadecimal | OCTal ¿
*RST condition: ASCii
Command Reference 9-39
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:FORMat :TINFormation
PM6681
8 Boolean
Timestamping On/Off Timestamping;On/Off
This command turns on/off the time stamping of measurements. Time stamping is
always done at the start of a measurement with a resolution of 125 ns, and is
saved in the measurement buffer together with the measurement result.
The setting of this command will affect the output format of the MEASure, READ
and FETCh queries.
For :FETCh:SCALar?, :READ:SCALar? and :MEASure:SCALar? the readout will con-
sist of two values instead of one. The first will be the measured value and the next
one will be the timestamp value.
In :FORMat ASCii mode, the result will be given as a floating-point number (NR3
format) followed by the timestamp in seconds in the NR2 format ddd.ddddddddd
(12 digits). In :FORMat REAL mode, the result will be given as an eight-byte block
containing the floating-point measured value, followed by a four-byte block con-
taining the integer timestamp count, where each count represents 125 nanosec-
onds.
When doing readouts in array form, with :FETCh :ARRay?, :READ :ARRay?, or
:MEASure :ARRay? , the response will consist of alternating measurement values
and timestamp values, formatted the same way as for scalar readout. All values
will be separated by commas.
Parameters <Boolean> = (1 / ON | 0 / OFF)
Returned format: 1|0 ¿
*RST condition: OFF
9-40 Command Reference
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:INITiate
PM6680B/81/85
Initiate Measurement
The :INITiate command initiates a measurement. Executing an :INITiate com-
mand changes the counter’s trigger subsystem state from “idle-state” to
the other states, depending on programming. With the *RST setting, the trigger
subsystem will bypass all its states and make a measurement, then return to idle
state. See also ‘How to use the Trigger Subsystem’ at the end of this chapter.
Complies to standards:
SCPI 1991.0, confirmed.
:INITiate :CONTinuous
PM6680B/81/85
8 <Boolean>
Continuously Initiated
The trigger system could continuously be initiated with this command. When Con-
tinuous is OFF, the trigger system remains in the “idle-state” until Continuous is set
to ON or the :INITiate is received. When Continuous is set to ON, the comple-
tion of a measurement cycle immediately starts a new trigger cycle without enter-
ing the “idle-state”, i.e., the counter is continuously measuring and storing re-
sponse data.
Returned format: <Boolean>¿
*RST condition: OFF
Complies to standards:
SCPI 1991.0, confirmed.
9-42 Command Reference
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Input Subsystems
n INPUT A
:INPut[1]
:ATTenuation
8
8
8
<Numeric value>|MIN|MAX (1|10)
AC|DC
<Numeric value>|MIN|MAX
(Not PM6685)
(Not PM6685)
:COUPling
:IMPedance
[:EVENt]
:HYSTeresis
8
8
8
8
8
«<Decimal data>|MAX |MIN»
ON|OFF|ONCE
<Numeric value>|MIN|MAX
ON|OFF|ONCE
POS|NEG
(Only PM6685)
(Only PM6685)
:AUTO
:AUTO
:LEVel
:SLOPe
:FILTer
[:LPASs]
[:STATe]
8
ON|OFF
n INPUT B (Not PM6685)
:INPut2
:ATTenuation
:COUPling
:IMPedance
[:EVENt]
8
8
8
<Numeric value>|MIN|MAX (1|10)
AC|DC
<Numeric value>|MIN|MAX
:LEVel
:AUTO
:SLOPe
:COMMon
8
8
8
8
<Numeric value>|MIN|MAX
ON|OFF|ONCE
POS|NEG
ON|OFF
n INPUT E
:INPut4
[:EVENt]
:SLOPe
8
POS|NEG
Command Reference 9-43
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:INPut«[1]|2» :ATTenuation
PM6680B PM6681
8 «<Numeric value>|MAX|MIN»
Attenuation
Attenuates the input signal with 1 or 10. The attenuation is automatically set if the
input level is set to AUTO.
Parameters:
<Numeric values> â 5, and MIN gives attenuation 1.
<Numeric values> > 5, and MAX gives attenuation 10.
Returned format:
1.00000000000E+000|1.00000000000E+001 ¿
Example for Input A (1)
:INP:ATT 8 10
SEND→
Example for Input B (2)
SEND® :INP2:ATT 8 10
*RST condition Input A (1) and Input B (2): 1 (but set by autotrigger since AUTO is on af-
ter *RST. (:INP:LEV:AUTO 8 ON).
Complies to standards:
SCPI 1991.0, confirmed.
:INPut«[1]|2» :COUPling
PM6680B PM6681
8 «AC|DC»
AC/DC Coupling
Selects AC coupling (normally used for frequency measurements), or DC cou-
pling (normally used for time measurements).
Returned format:
AC|DC¿
Example for Input A (1)
SEND® :INP:COUP 8 DC
Example for Input B (2)
SEND® :INP2:COUP 8 AC
*RST condition
Input A (1): AC
Input B (2): DC
Complies to standards:
SCPI 1991.0, confirmed.
9-44 Command Reference
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PM6680B/81/85
:INPut :FILTer
8 <Boolean>
Low Pass Filter
Switches on or off the low pass filter on input 1 (A). It has a cutoff frequency of 100
kHz.
Parameters:
<Boolean> is (1 / ON | 0 / OFF)
Returned format: 1|0¿
*RST condition OFF
Complies to standards:
SCPI 1991.0, confirmed.
PM6685
:INPut :HYSTeresis
8 «<Decimal data>|MAX |MIN»
Sensitivity
The sensitivity setting on the front panel is called HYSTeresis from the bus. The
range is 27.12 mV to 75.4 V. This setting has no effect unless autosensitivity is
turned off, see the following page.
Note that the sensitivity setting is coupled with the hysteresis setting according to
the formula:
Trigger Level + Hysteresis
< 37.7057 K
2
Parameters: <Decimal data> is a number between 27.12E-3 and 75.4.
MAX gives +75.4 V, MIN gives +2.7 mV
When using MAX as data, the counter always tries to set the hysteresis to +75.4 V.
Unless the Trigger level is set to 0, this setting is impossible, and the counter will
return an error message.
Returned format: <Decimal data>
Example:
:INP:HYST 8 0.5;HYST:AUTO 8 0
SEND→
This example sets the sensitivity to 0.5 V and switches off autosensitivity.
*RST condition 0.65 V (but controlled by Autotrigger since AUTO is on after *RST)
Command Reference 9-45
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:INPut :HYSTeresis :AUTO
PM6685
8 «<Boolean>|ONCE»
Auto Sensitivity
AUTO from the front panel turns on both auto sensitivity (hysteresis) and auto
waveform compensation(trigger level). From the bus there are two commands, one
for auto hysteresis and one for auto trigger level. However, the function of these
commands are identical. Both commands turn on/off the hysteresis and the trigger
level simultaneously.
The auto sensitivity function normally sets the hysteresis to 33% of Vpp. However,
two exceptions exists: Pulse Width and Duty Cycle, where the hysteresis is set to
min.
If you have a stable amplitude, use the :AUTO 8 ONCE, and the autotrigger will de-
termine sensitivity once and then set fixed levels.
Parameters <Boolean> = ( 1/ON | 0/OFF )
ONCE means that AUTO first switches ON to check the signal. After determining suitable sen-
sitivity and trigger level setting, it programs these values as if they where manually set.
It ends by switching off AUTO. Using ONCE instead of AUTO ON improves measuring
speed.
Returned format: 1|0¿
Example:
SEND® :INP:HYST:AUTO 8 OFF
This example switches off AUTO, enabling manual sensitivity and trigger level set-
ting.
*RST condition ON
9-46 Command Reference
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PM6680B/81/85
:INPut«[1]|2» :IMPedance
8 «<Decimal data>|MAX|MIN»
Input Impedance
The impedance can be set to 50 W or 1 MW.
Parameters
MIN or <Decimal data> that rounds off to 50 or less, sets the input impedance to 50
MAX or <Decimal data> that rounds off to 1001 or more, sets the impedance to 1 MW.
Returned format:
5.00000000000E+001|1.00000000000E+6¿
Example for Input A (1)
SEND® :INP:IMP 8 50
Sets the input A impedance to 50 W.
Example for Input B (2) (Only for PM6680B/81)
SEND® :INP2:IMP 8 50
Sets the input B impedance to 50 W.
*RST condition 1 MW
Complies to standards:
SCPI 1991.0, confirmed.
PM6680B PM6681
:INPut«[1]|2» :LEVel
8 «<Decimal data>|MAX|MIN»
Fixed Trigger Level
Input A and input B can be individually set to autotrigger or to fixed trigger levels of
between –5 V and +5 V in steps of 0.02 V (1.25mV for PM6681). If the attenuator
is set to 10X, the range is –50 V and +50 V in 0.2 V(12.5mV steps).
For autotrigger, see the following page.
Parameters: <Decimal data> is a number between –5 V and +5 V if att=1X and between
–50 V and +50 V if att=10X.
MAX gives +50 V and MIN gives –50 V
When using MAX and MIN as data, the counter always tries to set the trigger level to
+50 V and –50 V. If the attenuator is set to 1X, it is impossible to set this trigger level,
and the counter will return an error message.
Returned format:
<Decimal data>¿
Example for Input A (1)
SEND® :INP:LEV 8 0.01
Example for Input B (2)
SEND® :INP2:LEV 8 2.0
*RST condition 0 (but controlled by Autotrigger since AUTO is on after *RST)
Command Reference 9-47
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:INPut :LEVel
PM6685
8 «<Decimal data>|MAX|MIN»
Waveform compensation
The three-position waveform compensation on the front panel is not available
from the bus. Instead, you can set the trigger level, that is, the level on which the
hysteresis band is centered. How to set the trigger level depends on the duty cycle
and the peak-to-peak voltage of the signal.
Trigger level = V * (0.5- Duty factor )
pp
This setting has no effect unless autosensitivity is turned off, see the following
page.
Parameters
<Decimal data> is a number between approximately –37.7 V and +37.7 V.
MAX gives +37.7 ... V and MIN gives –37.7... V
Note that the 8 :INP:LEV command is coupled with the :INP:HYST command.
See page 9-45.
Returned format: <Decimal data>¿
Example:
SEND® :INP:LEV 8 3.75;LEV:AUTO 8 0
This example sets the trigger level to 3.75 V and switches off auto trigger level.
*RST condition 0 (but controlled by Autotrigger since AUTO is on after *RST)
9-48 Command Reference
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PM6680B PM6681
:INPut :LEVel :AUTO
8 «<Boolean>|ONCE»
Autotrigger
If set to AUTO, the counter automatically controls both the trigger level and the at-
tenuation1. If you have a stable amplitude, use the :AUTO 8 ONCE, and the
autotrigger will determine the trigger level once and then set a fixed level.
From the bus, input A and input B are always set to autotrigger individually.
+
Parameters:
<Boolean> = ( 1/ON | 0/OFF )
ONCE means that the autotrigger switches on, checks the signal, stores the trigger
levels as manually set levels, and then switches off auto. This improves measuring
speed.
Example for Input A (1)
SEND® :INP:LEV:AUTO 8 OFF
Example for Input B (2)
SEND® :INP2:LEV:AUTO 8 ON
Returned format: 1|0¿
*RST condition ON
1
The autotrigger function normally sets the trigger levels to 50 % of the signal ampli-
tude. Two exceptions exists however:
Rise/Fall time measurements: Here the input 1 (A) trigger level is set to 10% and
the Input 2 (B) trigger level is set to 90% of the amplitude.
Variable Hysteresis mode (channel 7): The input 1 (A) trigger level is set to 75%
and the Input 2 (B) trigger level is set to 25% of the amplitude
Command Reference 9-49
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:INPut :LEVel :AUTO
PM6685
8 «<Boolean>|ONCE»
Autotrigger
:INPut:AUTO?
If auto is on, the counter automatically controls the trigger level1 and the hyster-
esis. If you have a stable amplitude, use the :AUTO ONCE, and auto will determine
the trigger level once, and then set fixed levels.
Parameters
<Boolean> = ( 1/ON | 0/OFF )
ONCE means that AUTO first switches ON to check the signal. After determining suitable sen-
sitivity and trigger level setting, it programs these values as if they where manually set.
It ends by switching off AUTO.
Using ONCE instead of AUTO ON improves measuring speed.
Returned format: 1|0¿
Example:
SEND® :INP;LEV:AUTO 8 OFF
This example switches off AUTO, enabling the programmed trigger level setting.
*RST condition ON
1
The autotrigger measure peak to peak level, and sets the lower level of the hyster-
esis band to 33%, and the upper level to 66% of the value, ( for pulse and duty
factor measurement, both levels are set to 50% ).
9-50 Command Reference
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PM6680B/81/85
:INPut«[1]|2|4» :SLOPe
8 «POS|NEG»
Trigger Slope
Selects if the counter should trigger on a positive or a negative transition. Selecting
negative slope is useful when measuring negative pulse width and negative duty
cycle.
When you select negative slope, the counter always uses the non-prescaled
mode, limiting the maximum input frequency to 160 MHz. This can be useful when
you want to make fast frequency measurements: Using positive slope, the counter
needs two input cycles to make a SINGLE frequency measurement, but when set
to negative slope, only one input cycle is required.
Returned format:
POS | NEG ¿
Example for Input A (1)
SEND® :INP:SLOP 8 POS
Example for Input B (2)
(Only for PM6680B/81)
SEND® :INP2:SLOP 8 NEG
Example for Input E (4)
SEND® :INP4:SLOP 8 NEG
*RST condition POS
Complies to standards:
SCPI 1991.0, confirmed.
PM6680B PM6681
:INPut2:COMMon
ON|OFF
When on, the signal on input A is fed both to Channel 1 and Channel 2. The inter-
connection is made before the filter on input A.
Parameters
<Boolean> = ( 1/ON | 0/OFF )
ON means that the signal on input A is fed both to Channel 1 and Channel 2. The input signal
on input B is not used in the measurement. But the signal on input B is terminated by
the input impedance of the counter (50W or 1MW).
OFF means that inputs A and B works separated from each other.
Returned format: 1|0¿
Example:
SEND® :INP2:COMM ON
This example switches on common, feeding the same signal to both channel 1 and
channel 2.
*RST condition OFF
Command Reference 9-51
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Measurement Function
Set up the Instrument, Perform Measurement, and Read Data
:MEASure
[:SCALar]<Measuring Function>?
[<Parameters>][,(<Channels>)]
:ARRay<Measuring Function>?
:MEMory?
8
(<Array Size>)[,<Parameters>][,(<Channels>)]
[<N>]
:MEMory<N>?
The array size for :MEASure and :CONFigure, and the channels, are expression
data that must be in parentheses ( ).
+
+
The default channels, which the counter uses when you omit the channels in
the command, are printed in italics in the channel list on the following pages.
If you want to check what function and channels the counter is currently using,
send :CONF?
This query gives the same answer as :FUNC? in the SENSe subsystem
Command Reference 9-53
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PM6680B PM6681
:MEASure|:CONFigure
[:VOLTage]
[:SCALar]
:FREQuency
[:CW]?
[ _ [<expected value>[,<resolu-
tion>],][(@1|@2|@3|@4|@5|@6|@7)]]
:RATio?
:BURSt?
:PRF?
[ _ [<exp. value>[,<resol.>],][(@1|@2|@3|@4),(@1|@2|@3|@4)]]
[ _ [<exp. value>[,<resol.>],][(@1|@2|@3|@4|@5|@6|@7)]]
[ _ [<exp. value>[,<resol.>],][(@1|@2|@3|@4|@5|@6|@7)]]
[ _ [<exp. value>[,<resol.>],][(@1|@2|@3|@4|@5|@6|@7)]]
[ _ [<exp. value>[,<resol.>],][(@1|@2|@4),(@1|@2|@4)]]
[ _ [<exp. value>[,<resol.>],][(@1|@2),(@1|@2)]]
[ _ [<exp. value>[,<resol.>],][(@1|@2|@4)]]
:PERiod?
:TINTerval?
:PHASe?
:NWIDth?
:PWIDth?
[ _ [<exp. value>[,<resol.>],][(@1|@2|@4)]]
:DCYCle|PDUTycycle? [ _ [<exp. value>[,<resol.>],][(@1|@2|@4)]]
:NDUTycycle?
:RISE:TIME?[ _ [<lower thresh.>[,<upper thresh.>[,<exp. value>[,<resol.>]]],][(@1|@2)]]
:FALL:TIME? [ _ [<lower thresh.>[,<upper thresh.>[,<exp. value>[,<resol.>]]],][(@1|@2)]]
[ _ [<exp. value>[,<resol.>],][(@1|@2|@4)]]
:MAXimum?
:MINimum?
:PTPeak?
[ _ (@1|@2)]
[ _ (@1|@2)]
[ _ (@1|@2)]
:TOTalize
:GATed?[
:TIMed?
_
[_(@1|@2|@4),(@1|@2|@4)]
[ _ [<Time for gate open>,][ (@1|@2|@4),(@1|@2|@4)]]
:ACCumulated?[ _ [<Time for gate open>,][ (@1|@2|@4),(@1|@2|@4)]]
:SSTop? [ _ (@1|@2|@4),(@1|@2|@4)]
[:CONTinuous*][ _ [(@1|@2|@4),(@1|@2|@4)]
:ARRay
:FREQuency
[:CW]?
_
(<Size>)[,[<expected value>[,<resolution>],] [(@1|@2|@3|@4|@5|@6|@7)]]
:RATio? _ (<Size>)[,[<exp. value>[,<resol.>],][(@1|@2|@3|@4),(@1|@2|@3|@4)]]
:BURSt? _ (<Size>)[,<exp. value>[,<resol.>],][(@1|@2|@3|@4)]]
:PRF?
_
_
_
_
_
_
(<Size>)[,<exp. value>[,<resol.>],][(@1|@2|@3|@4)]]
(<Size>)[,<exp. value>[,<resol.>],][(@1|@2|@3|@4)]]
(<Size>)[,[<exp. value>[,<resol.>],][(@1|@2|@4),(@1|@2|@4)]]
(<Size>)[,[<exp. value>[,<resol.>],][(@1|@2),(@1|@2)]]
(<Size>)[,[<exp. value>[,<resol.>],][(@1|@2|@4)]]
(<Size>)[,[<exp. value>[,<resol.>],][(@1|@2|@4)]]
:PERiod?
:TINTerval?
:PHASe?
:NWIDth?
:PWIDth?
:DCYCle|PDUTycycle?
_
(<Size>)[,[<exp. value>[,<resol.>],][(@1|@2|@4)]]
:NDUTycycle? _ (<Size>)[,[<exp. value>[,<resol.>],][(@1|@2|@4)]]
:RISE:TIME? _ (<Size>)[,[<lower thr..>[,<upper thr.>[,<exp. value>[,<resol.>]]],][(@1|@2)]]
:FALL:TIME? _ (<Size>)[,[<lower thr.>[,<upper thr.>[,<exp. value>[,<resol.>]]],][(@1|@2)]]
:MAXimum?
:MINimum?
:PTPeak?
_
_
_
(<Size>)[,[(@1|@2)]
(<Size>)[,[(@1|@2)]
(<Size>)[,[(@1|@2)]
:TOTalize?
:GATed? _ (<Size>)[,[(@1|@2|@4),(@1|@2|@4)]]
:TIMed? _ (<Size>)[,[<Time for gate open>,][(@1|@2|@4),(@1|@2|@4)]]
:ACCumulated? _ (<Size>)[,[<Time for gate open>,][(@1|@2|@4),(@1|@2|@4)]]
:SSTop? _ (<Size>)[,[(@1|@2|@4),(@1|@2|@4)]]
[:CONTinuous*]
_
(<Size>)[,[(@1|@2|@4),(@1|@2|@4)]]
9-54 Command Reference
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PM6685
:MEASure|:CONFigure
[:VOLTage]
[:SCALar]
:FREQuency
[:CW]?
[ 8 [<expected value>[,<resolu-
tion>]][,(@1|@3|@4|@5|@6)]]
[ 8 [<exp. value>[,<resol.>]][,(@1|@3|@4|@5|@6),
:RATio?
(@1|@3|@4|@5|@6)]]
:BURSt?
:PRF?
[ 8 [<expected value>[,<resolution>]][,(@1|@3|@4)]]
[ 8 [<expected value>[,<resolution>]][,(@1|@3|@4)]]
[ 8 [<expected value>[,<resolution>]][,(@1|@3|@4)]]
[ 8 [<threshold>[,(@1|@4)]]
:PERiod?
:NWIDth?
:PWIDth?
[ 8 [<threshold>[,(@1|@4)]]
:PDUTycycle|DCYCle?[ 8 [<threshold>][,(@1|@4)]]
:NDUTycycle?
:TOTalize*
[ 8 [<threshold>][,(@1|@4)]]
[:CONTinuous]*[ 8 (@0|@1|@4)[,(@0|@1|@4)]
[:ARRay]
:FREQuency
[:CW]? 8 (<Size>)[,[<expected value>[,<resolution>]][,(@1|@3|@4|@5|@6)]]
:RATio? 8 (<Size>)[_,[<exp. value>[,<resol.>]][,(@1|@3|@4),(@1|@3|@4)]]
:BURSt? 8 (<Size>)[_,[<expected value>[,<resolution>]][,(@1|@3|@4)]]
:PRF?
8
(<Size>)[,[<expected value>[,<resolution>]] [,(@1|@3|@4)]]
:PERiod?
:NWIDth?
:PWIDth?
8
8
8
(<Size>)[,[<expected value>[,<resolution>]][,(@1|@3|@4)]]
(<Size>)[,[<threshold>[,(@1|@4)]]
(<Size>)[,[<threshold>[,(@1|@4)]]
:PDUTycycle|DCYCle? 8 (<Size>)[,[<threshold>][,(@1|@4)]]
:NDUTycycle?
:TOTalize*
8
(<Size>)[,[<threshold>][,(@1|@4)]]
[:CONTinuous*] 8 (<Size>)[,[(@0|@1|@4)[,(@0|@1|@4)]]
*
Only for :CONFigure
(@0) means that the input is disabled (Only PM6685)
(@1) means input A
(@2) means input B (Not available on PM6685)
(@3) means input C (HF-input option)
(@4) means input E (Rear panel arming input)
(@5) means input A prescaled by 2
(@6) means the internal reference
(@7) means input A with the variable hysteresis mode (Only PM6680B and
PM6681)
Command Reference 9-55
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:MEASure :<Measuring Function>?
PM6680B/81/85
[8 [<parameters>][ ,(<channels>)]]
Make one measurement
The measure query makes a complete measurement, including configuration and
readout of data. Use measure when you can accept the generic measurement
without fine tuning.
When a CONFigure command or MEASure? query is issued, all counter settings
are set to the *RST settings., except those specified as <parameters> and
<channels> in the CONFigure command or MEASure? query.
+
You cannot use the :MEASure? query for :TOTalize:CONTinuous, since this
function measures without stopping (continuously forever).
The :MEASure? query is a compound query identical to:
:ABORt;:CONFigure:<Meas_func>;:READ?
Parameters:
<Measuring Function>, <Parameters> and <Channels> are defined on page 9-54.
You may omit <parameters> and <Channels>, which are then set to default.
Returned format: <data>¿
Where: The format of the returned data is determined by the format commands: :FORMat and
:FORMat:FIXed.
Example:
SEND® :MEAS:FREQ? 8 (@3)
READ¬ 1.78112526833E+009
This example measures the frequency on the C-input and outputs the result to the
controller.
Type of command: Aborts all previous measurement commands if *WAI is not used.
Complies to standards:
SCPI 1991.0, confirmed.
9-56 Command Reference
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80B/81/85
:MEASure :ARRay :<Measuring Function>?
[ 8 (<array size>)[,[<parameters>] [,(<channels>)]]
Make an array of measurements
The :MEASure:ARRay query differs from the :MEASure query in that it performs
the number of measurements you decide in the <array size> and sends all the
measuring results in one string to the controller.
The array size for :MEASure and :CONFigure, and the channels, are expression
data that must be in parentheses ( ).
+
The :MEASure:ARRay query is a compound query identical to:
:ABORt;:CONFigure:ARRay:<Meas-func> 8 (<array-size>); :READ:ARRay? 8
(<array-size>)
Parameters:
<array size> sets the number of measurements in the array.
Returned format:
<Measuring result>{[,<measuring result>]}¿
Example:
SEND® :MEAS:ARR:FREQ? 8 (10)
Ten measuring results will be returned.
Type of command:
Complies to standards:
SCPI 1991.0, confirmed.
Command Reference 9-57
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:MEASure:MEMory<N>?
PM6681
Memory Recall, Measure and Fetch Result
Use this command when you want to measure several parameters fast.
:MEAS:MEM1? recalls the contents of memory 1 and reads out the result,
:MEAS:MEM2? recalls the contents of memory two and reads out the result etc.
The equivalent command sequence is *RCL1;READ?
The allowed range for <N> is 1 to 9. Use the somewhat slower :MEAS:MEMory?
N command described below if you must use memories 10 to 19.
TIMING
Data Format
Command
ASCii
7.9 ms
9.1 ms
10.1 ms
REAL
6.7 ms
8.0 ms
8.9 ms
:MEAS:MEM1?
:MEAS:MEM? 1
*RCL 1;READ?
Returned format:
<measurement result>¿
Complies to standards:
SCPI 1991.0, confirmed
:MEASure:MEMory?
PM6681
8 <N>
Memory Recall, Measure and Fetch Result
Same as above command but somewhat slower. Allows use of all memories (1 to
19).
Example: :MEAS:MEM 8 13
This example recalls the instrument setting in memory number 13, makes a meas-
urement, and fetches the result.
Complies to standards:
SCPI 1991.0, confirmed
9-58 Command Reference
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EXPLANATIONS OF THE MEASURING
FUNCTIONS
This sub-chapter explains the various measurements that can be
done with :MEASure and :CONFigure;:READ. Only the queries
for single measurements using the measure command are given
here, but all of the information is also valid for the :CONFigure
command and for both scalar (single) and array measurements.
PM6680B/81/85
:MEASure_«:DCYCle/:PDUTycycle»
[8 [<threshold>] [,(@«1|2|4|6»)]]
Positive Duty Cycle
Traditional duty cycle measurement is performed. That is, the ratio between the
on time and the off time of the input pulse is measured.
Parameters
<threshold> parameter sets the trigger levels in volts. If omitted, the auto trigger level is set to
50 percent of the signal.
(@«1|2|4|6») is the channel to measure on:
(@1) means input A
(@2) means input B (Only PM6680B and PM6681)
(@4) means input E (Rear panel arming input)
(@6) means the internal reference
If you omit the channel, the instrument measures on input A (@1).
Example:
SEND® :MEAS:PDUT?
READ¬ +5.097555E-001
In this example, the duty cycle is 50.97%
Complies to standards:
SCPI 1991.0, confirmed.
Command Reference 9-59
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:MEASure :FREQuency?
PM6680B/81/85
[8 [<expected value>[,<resolution>]] [,<(@«1|2|3|4|5|6|7»)>]]
Frequency
Traditional frequency measurements. The counter uses the <expected value> and
<resolution> to calculate the Measurement Time (:SENSe:ACQuisition:APER-
ture).
Example:
SEND® :MEAS:FREQ? 8 (@3)
READ¬ 1.78112526833E+009
This example measures the frequency at input C.
The channel is expression data and it must be in parentheses ( ).
+
Parameters:
<expected value> is the expected frequency,
<resolution> is the required resolution.
<(@«1|3|4|5|6|7»)> is the channel to measure on:
(@1) means input A1
(@2) means input B (Only PM6680B and PM6681)
(@3) means input C (HF-input option)
(@4) means input E (Rear panel arming input)
(@5) means input A prescaled by 2
(@6) means the internal reference
@7) means input A with the variable hysteresis mode (Only PM6680B and PM6681)
If you omit the channel, the instrument measures on input A (@1).
1 The A input is always prescaled by 2 when measuring Frequency A and
prescaled by 1 for all other functions.
Complies to standards:
SCPI 1991.0, confirmed.
9-60 Command Reference
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PM6680B/81/85
:MEASure :FREQuency :BURSt?
[8 [<expected value>[,<resolution>]] [,<(@«1|2|3|4|5|6|7»)>]]
Burst Carrier Frequency
Measures the carrier frequency of a burst. The burst duration must be less than
50% of the pulse repetition frequency (PRF).
How to measure bursts is described in detail in the Operators Manual.
The counter uses the <expected value> and <resolution> to select a Measurement
Time ([:SENSe]:ACQuisition:APERture), and then sets the sync delay
([:SENSe]:SDELay) to 1.5 * Measurement Time.
Parameters:
<expected value> is the expected carrier frequency,
<resolution> is the required resolution, e.g., 1 gives 1Hz resolution.
<(@«1|2|3|4|5|6|7»)> is the channel to measure on:
(@1) means input A
(@2) means input B (Only PM6680B and PM6681)
(@3) means input C (HF-input option)
(@4) means input E (Rear panel arming input)
(@5) means input A prescaled by 2
(@6) means the internal reference
(@7) means input A with the variable hysteresis mode (Only PM6680B/81)
If you omit the channel, the instrument measures on input A (@1).
Complies to standards:
SCPI 1992.0, confirmed.
Command Reference 9-61
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:MEASure :FREQuency :PRF?
PM6680B/81/85
[8 [<exp. val.>[,<res.>]][,<(@«1|2|3|4|5|6|7»)>]]
Pulse Repetition Frequency
Measures the PRF (Pulse Repetition Frequency) of a burst signal.The burst dura-
tion must be less than 50% of the pulse repetition frequency (PRF).
It is better to set up the measurement with the [:SENS]:FUNC “:FREQ:PRF”
command when measuring pulse repetition frequency. This command will allow
you to set a suitable sync delay with the [:SENSe]:Sync:DELay command.
+
How to measure bursts is described in detail in the Operators Manual.
Parameters: <exp. val.> is the expected PRF,
<res.> is the required resolution.
<(@«1|3|4|5|6»)> is the channel to measure on:
(@1) means input A
(@2) means input B (Only PM6680B and PM6681)
(@3) means input C (HF-input option)
(@4) means input E (Rear panel arming input)
(@5) means input A prescaled by 2
(@6) means the internal reference
(@7) means input A with the variable hysteresis mode (Only PM6680B/81)
If you omit the channel, the instrument measures on input A (@1).
The <expected value> and <resolution> are used to calculate the Measurement
Time ([:SENSe]:ACQuisition:APERture). The Sync. Delay is always 10 ms
(default value)
Complies to standards:
SCPI 1992.0, confirmed.
9-62 Command Reference
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PM6680B PM6681 :MEASure :FALL :TIME?
[8 [<lower threshold> [,<upper threshold>[,<expected value>[,<resolution>]]]] [,(@1)]]
Fall-time
The transition time from 90% to 10% of the signal amplitude is measured.
The measurement is always a single measurement and the Auto-trigger is always
on, setting the trigger levels to 90% and 10 % of the amplitude. If you need an av-
erage transition time measurement, or other trigger levels, use the :SENSe sub-
system and manually set trigger levels instead.
Parameters:
<lower threshold>, <upper threshold>, <expected value> and <resolution are all ignored by
the counter
<(@1)> is the channel to measure on, i.e., input A
Complies to standards:
SCPI 1991.0, confirmed.
PM6680B/81/85
:MEASure :FREQuency :RATio?
[8 [<expected value> [,<resolution>]][,<(@«1|2|3|4|5|6»)>,<(@«1|2|3|4|5|6»)>]]
Frequency Ratio
Frequency ratio measurements between two inputs.
Example:
SEND® :MEAS:FREQ:RAT? 8 (@1),(@3)
READ¬ 2.345625764333E+000
This example measures the ratio between input A and input C.
The channel is expression data and it must be in parentheses ( ).
+
Parameters: <expected value> and <resolution> are ignored
<(@«1|2|3|4|5|6»)>,<(@«1|2|3|4|5|6»)> is the channels to measure on:
(@1) means input A
(@2) means input B (Only PM6680B and PM6681)
(@3) means input C (HF-input option)
(@4) means input E (Rear panel arming input)
(@5) means input A prescaled by 2
(@6) means the internal reference
If you omit the channel, the instrument measures between input A and input E.
Complies to standards:
SCPI 1991.0, confirmed.
Command Reference 9-63
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:MEASure [:VOLT] :MAXimum?
PM6680B PM6681
[ 8 («@1|@2»)]
Positive Peak Voltage
This command measures the positive peak voltage with the input DC coupled.
Parameters:
(«@1|@2») is the channel to measure on
(@1) means input A
(@2) means input B
Complies to standards:
SCPI 1991.0, confirmed.
:MEASure [:VOLT] :MINimum?
PM6680B PM6681
[ 8 («@1|@2»)]
Negative Peak Voltage
This command measures the negative peak voltage with the input DC coupled
Parameters:
(«@1|@2») is the channel to measure on
(@1) means input A
(@2) means input B
Complies to standards:
SCPI 1991.0, confirmed.
9-64 Command Reference
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PM6680B/81/85
:MEASure :NWIDth?
[8 [<threshold>] [,<(@«1|2|4|6»)>]]
Negative Pulse Width
A negative pulse width measurement is performed.
This is always a single measurement. If you need an average pulse width mea-
surement, use the :SENSe subsystem instead.
Parameters
<threshold> parameter sets the trigger levels in volts. If omitted, the auto trigger level is set to
50 percent of the signal.
<(@«1|2|4|6»)> is the channel to measure on:
(@1) means input A
(@2) means input B (Only PM6680B and PM6681)
(@4) means input E (Rear panel arming input)
(@6) means the internal reference
If you omit the channel, the instrument measures on input A.
Complies to standards:
SCPI 1991.0, confirmed.
PM6680B/81/85
:MEASure :PWIDth?
[8 [<threshold>] [,<(@«1|2|4|6»)>]]
Positive Pulse Width
A positive pulse width measurement is performed.
This is always a single measurement. If you need an average pulse width mea-
surement, use the :SENSe subsystem instead.
Parameters
<threshold> parameter sets the trigger levels in volts. If omitted, the auto trigger level is set to
50 percent of the signal.
<(@«1|2|4|6»)> is the channel to measure on:
(@1) means input A
(@2) means input B (Only PM6680B and PM6681)
(@4) means input E (Rear panel arming input)
(@6) means the internal reference
If you omit the channel, the instrument measures on input A.
Complies to standards:
SCPI 1991.0, confirmed.
Command Reference 9-65
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:MEASure_«:PDUTycycle/ :DCYCle»?
PM6680B/81/85
[8 [<threshold>] [,(@«1|2|4|6»)]]
Positive duty cycle: Duty Factor
Traditional duty cycle measurement is performed. That is, the ratio between the on
time and the off time of the input pulse is measured.
Parameters
<threshold> parameter sets the trigger levels in volts. If omitted, the auto trigger level is set to
50 percent of the signal.
(@«1|2|4|6») is the channel to measure on:
(@1) means input A
(@2) means input B (Only PM6680B and PM6681)
(@4) means input E (Rear panel arming input)
(@6) means the internal reference
If you omit the channel, the instrument measures on input A (@1).
Example:
SEND® MEAS:PDUT?
+5.097555E-001
READ¬
In this example, the duty cycle is 50.97%
Complies to standards:
SCPI 1991.0, confirmed.
:MEASure_«:NDUTycycle»?
PM6680B/81/85
[8 [<threshold>] [,(@«1|2|4|6»)]]
Negative duty cycle: Duty Factor
Traditional duty cycle measurement is performed. That is, the ratio between the on
time and the off time of the input pulse is measured.
Parameters
<threshold> parameter sets the trigger levels in volts. If omitted, the auto trigger level is set to
50 percent of the signal.
(@«1|2|4|6») is the channel to measure on:
(@1) means input A
(@2) means input B (Only PM6680B and PM6681)
(@4) means input E (Rear panel arming input)
(@6) means the internal reference
If you omit the channel, the instrument measures on input A (@1).
Example:
SEND® MEAS:PDUT?
+5.097555E-001
READ¬
In this example, the duty cycle is 50.97%
Complies to standards:
SCPI 1991.0, confirmed.
9-66 Command Reference
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PM6680B/81/85
:MEASure :PERiod?
[8 [<expected value> [,<resolution>]][,<(@«1|2|3|4|5|6|7»)>]]
Period
A traditional period measurement is performed.
The <expected value> and <resolution> are used to calculate the Measurement
Time ([:SENSe]:ACQuisition:APERture).
Parameters:
<expected value> is the expected Period,
<resolution> is the required resolution,
<(@«1|2|3|4|5|6»)> is the channel to measure on:
(@1) means input A
(@2) means input B (Only PM6680B and PM6681)
(@3) means input C (HF-input option)
(@4) means input E (Rear panel arming input)
(@5) means input A prescaled by 2
(@6) means the internal reference
(@7) means input A with the variable hysteresis mode (Only PM6680B)PM6681)
If you omit the channel, the instrument measures on input A (@1).
Complies to standards:
SCPI 1991.0, confirmed.
PM6680B PM6681
:MEASure :PHASe?
[8 [<expected value>[,<resolution>]] [,(@«1|2»),(@«1|2»)]]
Phase
A traditional PHASe measurement is performed.
Parameters:
<expected value> and <resolution> are ignored by the counter
The first (@«1|2») is the start channel and the second (@«1|2») is the stop channel
(@1) means input A
(@2) means input B
If you omit the channel, the instrument measures between input A and input B.
Complies to standards:
SCPI 1991-0, approved.
Command Reference 9-67
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:MEASure [:VOLT] :PTPeak?
PM6680B PM6681
[8 (@«1|2»)].
Peak-to-Peak Voltage
This command make measures the peak-to-peak voltage with the input DC cou-
pled.
Parameters:
(@«1|2») is the channel to measure on
(@1) means input A
(@2) means input B
Complies to standards:
SCPI 1991.0, confirmed.
:MEASure :RISE :TIME? PM6680B PM6681
[8 [<lower threshold> [,<upper threshold>[,<expected value>[,<resolution>]]]] [,(@1)]
Rise-time
The transition time from 10% to 90% of the signal amplitude is measured.The
measurement is always a single measurement and the Auto-trigger is always on,
setting the trigger levels to 10% and 90 % of the amplitude. If you need an aver-
age transition time measurement or other trigger levels, use the :SENSe subsys-
tem and manually set trigger levels instead.
Parameters:
<lower threshold>, <upper threshold>, <expected value> and <resolution are all ignored by
the counter
<(@1)> is the channel to measure on, i.e., input A
Complies to standards:
SCPI 1991.0, confirmed.
9-68 Command Reference
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PM6680B PM6681
:MEASure :TINTerval?
8 (@«1|2|4»),(@«1|2|4»)]
Time-Interval
Traditional time-interval measurements are performed. The trigger levels are set
automatically, and positive slope is used. The first channel in the channel list is the
start channel, and the second is the stop channel.
Parameters:
The first (@«1|2|4») is the start channel and the second (@«1|2|4») is the stop channel
(@1) means input A
(@2) means input B
(@4) means input E (Rear panel arming input)
If you omit the channel, input A is the start channel, and input B is the stop chan-
nel.
Command Reference 9-69
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:MEASure :TOTalize :ACCumulated?
PM6680B PM6681
[8 <time for gate open>][,(@«1|2|4|5|6») [,(@«1|2|4|5|6»)]]
Totalize X gated by Y, accumulated
The counter totalizes the pulses on the primary channel. The totalizing starts when
the gate signal on the secondary channel goes on and stops when the gate signal
goes to off. The polarity of on/off is controlled via the :INPut:SLOPe command of
the gate channel. The result is the sum of counts in all the gate openings that oc-
cur during a preset time <time for gate open>.
If you use the :CONFigure command, you can select if the counter should count
positive or negative transitions with the :INPut:SLOPe command of the measur-
ing channel.
Parameters: <time for gate open> is the time you want the totalizing to proceed. Range
PM6680B: is 0.8E–6, 1.6E–6, 3.2E–6, 6.4E–6, 12.8E–6, and 50E–6 to 400 s
Range PM6681 and 80E–9, 160E–9, 320E–9, 640E–9, 1.28E–6, and 20E–6 to
400 s.
The first <(@«1|2|4|5|6»)> is the channel to measure on.
The second <(@«1|2|4|5|6»)> is the gate channel.
(@1) means input A
(@2) means input B
(@4) means input E (rear panel arming input)
(@5) means input A prescaled by 2
(@6) means the internal reference
If you omit the channels, the instrument measures on input A with input B as
the gate channel.
+
Time for gate open = 10 ms ([:SENSe]ACQuisition:APERture)
*RST condition:
9-70 Command Reference
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PM6680B/81/85
:CONFigure :TOTalize :CONTinuous
[8 (@«1|2|4|6»)][,(@«1|2|4|6»)]
Totalize Manually
This is a count/totalize function controlled from the GPIB interface using the com-
mand SENS:TOT:GATE8ON|OFF.
The counter counts up for each event on the primary input channel. and down on
the secondary channel. The result is the difference between the primary and sec-
ondary channel. In addition to selecting totalizing, the :CONF:TOT:CONT com-
mand also selects positive trigger slope. If you want to count negative slopes on in-
put A, send :INPut:SLOPe8 NEG after the :CONF:TOT:CONT command.
Parameters
(@«1|2|4|6») is the primary (adding)channel:
,(@«1|2|4|6») is the secondary (subtracting) channel:
(@1) means input A
(@2) means input B (not PM6685)
(@4) means input E (rear panel arming input)
(@6) means the internal reference
Selecting the same channel as both primary and secondary disables the secon-
dary channel.
This measurement cannot be done as a :MEASure, it must be done as a :CON-
Figure followed by :INIT:CONT8ON, gate control with :SENS:TOT:GATE
«ON|OFF» and completed with a :FETCh:ARR? <array size>.
+
Example:
SEND® :CONF:TOT;:INP:SLOPe neg
This example sets up the counter to totalize the negative slopes on Input A and
disable the secondary channel. (Same as (@1),(@1).)
*RST condition (@1),(@2) for PM6680B and PM6681, (@1),(@1) for PM6685
Normal Program Sequence for Totalizing on A
CONF:TOT:CONT8(@1),(@1)
INIT:CONT8ON
Set up the counter for totalize on A
Initiate the counter continuously
Start totalizing
TOT:GATE8ON
FETC:ARR?8–1
Read intermediate results without stopping the totalizing
Stop totalizing
TOT:GATE8OFF
FETC:ARR?8–1
Fetch the final result from the totalizing
The :FETCh:ARR? command can take both positive and negative data. Positive
data, for instance 10, outputs the first 10 measurements in the counter output
buffer. Negative data, for instance –10, outputs the last ten results.
Intermediate results When totalizing you often want to read the intermediate result without
stopping the totalizing process. :FETC:ARR?8–1 outputs such a result.
Command Reference 9-71
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:MEASure :TOTalize :GATed?
PM6680B PM6681
[8 (@«1|2|4|5|6») [,(@«1|2|4|5|6»)]]
Totalize X gated by Y
The counter totalizes the pulses on the primary channel. The totalizing starts when
the gate signal on the secondary channel goes on and stops when the gate signal
goes to off. The polarity of on/off is controlled via the :INPut:SLOPe command of
the gate signal.
Select if the counter should count positive or negative transitions with the
:INPut:SLOPe command of the measuring channel.
Parameters
The first <(@«1|2|4|5|6»)> is the channel to measure on, the second one is the gate channel:
(@1) means input A
(@2) means input B
(@4) means input E (rear panel arming input)
(@5) means input A prescaled by 2
(@6) means the internal reference
If you omit the channels, the instrument measures on input A with input B as the
gate channel.
:MEASure :TOTalize :SSTop?
PM6680B PM6681
[8 ,(@«1|2|4|5|6») [,(@«1|2|4|5|6»)]]
Totalize X start/stop by Y
The counter totalizes the pulses on the primary channel. The totalizing starts when
the gate signal on the secondary channel goes on and stops the next time the gate
signal goes on. The polarity of ON is controlled via the :INPut:SLOPe command
of the Start /stop channel.
Select if the counter should count positive or negative transitions with the :IN-
Put:SLOPe command of the measuring channel.
Parameters:
The first <(@«1|2|4|5|6»)> is the channel to measure on, and the second one is the start/stop
channel:
(@1) means input A
(@2) means input B
(@4) means input E (rear panel arming input)
(@5) means input A prescaled by 2
(@6) means the internal reference
If you omit the channels, the instrument measures on input A with input B is the
start/stop channel.
9-72 Command Reference
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PM6680B PM6681
:MEASure :TOTalize :TIMed?
[8 [<time for gate open> [,(@«1|2|4»)][,(@«1|2|4»)]]]
Totalize X-Y During a Preset Time
This is a count/totalize function during a predefined time. The start/stop signal is
generated by the counter and set by <time for gate open>.
The counter counts up for each event on the X-channel and down for each event
on the Y-channel. The result is the difference between the two channels.
If you only want to Totalize on X, you must disable Y by setting both X and Y to the
same channel or disconnecting the signal from Y.
Totalize –Y MANUAL, negative totalizing, is possible if you physically disconnect
the signal on the X input.
Select if the counter should count positive or negative transitions with the IN-
Put:SLOPe command of the channels.
Parameters:
<time for gate open> is the time you want the totalizing to proceed. The range is the same as
for Measurement Time.
The first <(@«1|2|4»)> is the channel that counts up, and the second one is the channel that
counts down:
(@1) means input A
(@2) means input B
(@4) means input E (rear panel arming input)
If you omit the channels, the instrument counts up on input A and down on input B.
Example:
SEND® :MEAS:TOT:TIM? 8 1,(@1),(@1)
In this example the counter totalises the pulses on Channel 1 for one second. Any
signals on channel 2 and 4 are ignored.
*RST condition:
Time for gate open = 10 ms ([:SENSe]:ACQuisition:APERture)
Command Reference 9-73
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:MEMory :DELete :MACRo
PM6680B/81/85
8 ‘<Macro name>’
Delete one Macro
This command removes an individual MACRo1.
Parameters
‘<Macro name>’ is the name of the macro you want to delete.
<Macro name> is String data that must be surrounded by quotation marks.
+
See also:
*PMC, if you want to delete all macros.
1
The proposed IEEE488.2 command *RMC (Remove Macro command) also works
on PM6685. It preforms exactly the same action as :MEMory:DELete:MACRo.
Note however that this command is not yet (1993) a certified IEEE488.2 com-
mand.
:MEMory :FREE :SENSe?
PM6681
Memory Free for results
This command gives information of the free memory available for sense data
(measuring results) in the counter.
Returned format:
<Data positions available>, <Data positions in use>¿
9-76 Command Reference
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PM6680B/81/85
:MEMory :FREE :MACRo?
Memory Free for Macros
This command gives information of the free memory available for MACRos in the
counter. If no macros are specified, 1160 bytes are available.
Returned format:
<Bytes available>, <Bytes used>¿
Complies to standards:
SCPI 1991.0, confirmed.
PM6680B/81/85
:MEMory :NSTates?
Memory States
The Number of States query (only) requests the number of *SAV/ ∗RCL instrument
setting memory states available in the counter. The counter responds with a value
that is one greater than the maximum that can be sent as a parameter to the *SAV
and *RCL commands. (States are numbered from 0 to max–1.)
Returned format:
<the number of states available>¿
Complies to standards:
SCPI 1991.0, confirmed
Command Reference 9-77
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:OUTPut
PM6680B/81/85
8 <Boolean>
Enable Analog Out
This command switches on/off the analog output. See also :OUTput:SCALe com-
mand on the next page.
Parameters
<Boolean> = ( 1/ON | 0/OFF )
Returned format: <1|0>¿
Example:
Send® :OUTP 8 1
Switches on the analog output.
*RST condition: OFF
Complies to standards:
SCPI 1991.0 confirmed.
:OUTPut :SCALe
PM6680B/81/85
8 < Decimal data >
Scaling Factor, Analog Output
This command sets the scaling factor for the analog output. The measurement re-
sult is scaled after math, if math is used.
If you want a full-scale output for a specific readout, the formula is:
1
Scaling factor =
full scale value
Parameters
<Decimal data> is the scaling factor. The range is –1020 to +1020.
Returned format: < Decimal data>¿
Example:
If you want full scale output (5 V) for a reading of 0.00359,
0.00359
Scaling factor =
= 0.000718
5
Send® :OUTP:SCAL 8 718E–6
*RST condition:
1
9-80 Command Reference
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:READ?
PM6680B/81/85
Read one Result
The read function performs new measurements and reads out a measuring result
without reprogramming the counter. Using the :READ? query in conjunction with
the :CONFigure command gives you a measure capability where you can fine tune
the measurement.
If the counter is set up to do an array of measurements, :READ? makes all the
measurements in the array, stores the results in the output buffer, and fetches the
first measuring result. Use FETCh? to fetch other measuring results from the out-
put buffer. The :READ? query is identical to :ABORt;:INITiate;:FETCh?
Returned format: <data>¿
The format of the returned data is determined by the format commands :FORMat
and FORMat:FIXed.
Example:
SEND® :CONF:FREQ;:INP:FILT 8 ON;:READ?
This example configures the counter to make a standard frequency measurement
with the 100 kHz filter on. The counter is triggered, and data from the measure-
ment are read out with the :READ? query.
SEND® :READ?
This makes a new measurement and fetches the result without changing the pro-
gramming of the counter.
Type of command: Aborts all previous measurement commands if *WAI is not used.
Complies to standards:
SCPI 1991.0, confirmed.
9-82 Command Reference
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PM6680B/81/85
:READ:ARRay?
8 «<array size for FETCh>|MAX»
Read an array of results
The :READ:ARRay? query differs from the :READ? query by reading out several
results at once after making the number of measurements previously set up by
:CONFigure:ARRay 8 or 8 :MEASure:ARRAy?.
The :READ:ARRay? query is identical to:
:ABORt;:INITiate;:FETCh:ARRay?_<array size for FETCh>
The <array size for FETCh> does not tell :READ to make that many measure-
ments, only to fetch that many results. :CONF:ARR, 8 :MEAS:ARR,
:ARM:LAY1:COUN or :TRIG:LAY1:COUN sets the number of measurements.
+
Parameters:
<array size for FETCh> sets the number of measuring results in the array. This size must be
equal or less than the number of measurements specified with :CONFigure.
MAX means that all the results in the output buffer will be fetched.
Returned format: <data>[,<data>]¿
The format of the returned data is determined by the format commands :FORMat
and :FORMat:FIXed.
SEND® :ARM:COUN 8 10;:READ:ARR? 8 5
This example configures the counter to make an array of 10 standard measure-
ments. The counter is triggered and data from the first five measurements are read
out with the :READ? query.
Type of command: Aborts all previous measurement commands if *WAI is not used.
Complies to standards:
SCPI 1991.0, confirmed.
Command Reference 9-83
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Sense Command Subsystem
n Sense Subsystem command tree for PM6680B and PM6681
[:SENSe]
:ACQuisition
:APERture
:HOFF
8
<meas time> | MIN | MAX
[:STATe]
8
8
8
8
8
ON | OFF
<hold off event count value> | MIN | MAX
TIME | EVENt
<hold off time value> | MIN | MAX
HIGH | LOW
:ECOunt
:MODE
:TIME
:RESolution
:AVERage
:COUNt
8
<Number of samples> | MIN | MAX
8
8
TIME | COUNts
ON|OFF
:STATe
:FREQuency
:RANGe
:LOWer
:FUNCtion
:INTernal
8
8
<Minimum frequency for autotrigger> | MIN | MAX
‘Measuring function [ Primary channel [ , Secondary channel ] ] ‘
:FORMat
:ROSCillator
8
8
REAL | PACKed
:SOURce
:TOTalize
INTernal | EXTernal
:GATE
[:STATe]
8
8
ON | OFF
ON | OFF
:VOLTage
:GATed
:STATe
Command Reference 9-85
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n Sense Subsystem command tree for PM6685
[:SENSe]
:FUNCtion
:EVENt1
8
‘Measuring function [_ Primary channel [ , Secondary channel ] ] ‘
:LEVel
:AUTO
:HYSTeresis
:AUTO
:SLOPe
8
8
8
8
8
<Trigger level in Volts> | MIN | MAX
ON | OFF | ONCE
<Sensitivity band in Volts> | MIN | MAX
ON | OFF | ONCE
POS | NEG
:ACQuisition
:APERture
:HOFF2
8
8
8
<Measurement Time> | MIN | MAX
<Hold off time> | MIN | MAX
ON | OFF
:TIME
:AVERage
:STATe
:ROSCillator
:SOURce
:SDELay
:TOTalize
:GATE
[:STATe]
8
8
INTernal | EXTernal
<Burst sync. delay> | MIN | MAX
8
8
<ON | OFF
:INTernal
:FORMat
REAL | PACKed
1
2
Alias commands for commands in the Input subsystem.
Alias commands fot the: SDELay command for compatibility with the PM6680B.
9-86 Command Reference
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PM6680B/85
:ACQuisition :APERture
8 «<Decimal value > |MIN|MAX»
Set the Measurement Time
Sets the gate time for one measurement.
Parameters: <decimal value> is 0.8E–6, 1.6E–6, 3.2E–6, 6.4E–6, or 12.8E–6 and
50E–6 to 400s.
MIN gives 800 ns and MAX gives 400 s.
Measurement Times of 800 ns to 12.8 ms work in :FREQ:CW, FREQ:BURST,
:FREQ:PRF, 8 :FREQ:RAT and :PERiod. If one of these short times is selected
when the counter makes other measurements, it will use 50 ms.
If you want to switch between Average and Single measurements, use the :AV-
ERage:STATe 8 ON|OFF in the Sense Subsystem.
+
When Single is selected and an array measurement is done, the Measurement
Time, set by :Acquisition:APERture, sets the time between the measure-
ments in the array. This means that if you want a very high speed, you must set
:AVER:STATE 8 OFF and :ACQ:APER 8 MIN.
Returned format: <Decimal value >¿
*RST condition: 10 ms
SYST:PRESet condition: 200 ms
PM6681
:ACQuisition :APERture
8 «<Decimal value > | MIN | MAX»
Set the Measurement Time
Sets the gate time for one measurement.
Measurement Times of 80 to 1280 ns work in :FREQ:CW, FREQ:BURST,
:FREQ:PRF, 8 :FREQ:RAT and :PERiod. If one of these short times is selected
when the counter makes other measurements, it will use 5 ms.
If you want to switch between Average and Single measurements, use the :AV-
ERage:STATe8 ON|OFF in the Sense Subsystem.
+
When Single is selected and an array measurement is done, the Measurement
Time, set by :Acquisition:APERture, sets the time between the measure-
ments in the array. This means that if you want a very high speed, you must set
:AVER:STATE 8 OFF and :ACQ:APER 8 MIN.
Parameters: <decimal value> is 80, 160, 320, 640, 1280 ns and 20 ms to 400 s.
MIN gives 80 ns and MAX gives 400 s.
Returned format:
<Decimal value >¿
*RST condition: 10 ms
SYST:PRESet condition: 200 ms
Command Reference 9-87
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:ACQuisition :HOFF
PM6680B PM6681
8 <boolean>
Hold Off On/Off
Switches the Hold Off function On/Off.
Parameters:
<Boolean> = 1 / ON | 0 / OFF
Returned format: 1 | 0¿
*RST condition: OFF
:ACQuisition :HOFF: ECOunt
PM6680B PM6681
8 «<Decimal value>|MIN|MAX»
Hold Off, set event counter
Sets the Hold Off event value. The counter counts negative events on the B input
(channel 2).
Parameters:
<decimal value> is a number in the range 2 to 16 777 215.
Returned format: <Decimal value>¿
*RST condition: 100
9-88 Command Reference
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PM6680B PM6681
:ACQuisition :HOFF :MODE
8 «TIME|EVENt»
Hold Off Mode
Selects if triggering is going to be disabled for a preset time or for a preset number
of events.
When set to event, the counter counts negative edges on the B input (channel 2).
This function is coupled to the :ARM:START:DEL, :ARM:START:ECO,
:ARM:STOP:DEL and :ARM:STOP:ECO. The different delays must all be of the
same type, (Time or Event). This means that setting one of them to Event delay
causes the others to be set to Event delays.
Parameters:
TIME
EVENt
Returned format:
TIME| EVENt¿
*RST condition:
TIME
PM6680B PM6681
:ACQuisition :HOFF :TIME
8 «<Decimal value> |MIN|MAX»
Hold Off Time
Sets the Hold Off time value.
Parameters:
<Decimal data> = a number between 200E–9 and 1.6777215 for PM6680B,
and between 40E–9 and 1.34217727 for PM6681.
Returned format:
<Decimal value>¿
*RST condition:
10 ms for PM6680B and 1 ms for PM6681
Command Reference 9-89
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:ACQuisition :RESolution
PM6680B
8 «HIGH|LOW»
Resolution
Selects basic measurement mode for all time-related measurements.
Parameters:
HIGH: The resolution is the full 0.25 ns
LOW: The resolution is limited to a 100-ns clock. You can use this to increase the
bus speed. Saves about 0.6 to 0.9 ms if the counter does real-time calculations,
otherwise, only 0.05 ms.
Returned format:
HIGH|LOW¿
*RST condition:
HIGH
:ACQuisition :RESolution
PM6681
8 «HIGH|LOW»
Resolution
Turns off interpolator usage and also ignores the high resolution part of the count
registers. Low Resolution functions only for Frequency, Period, Time-Interval and
Pulse Width
Parameters:
HIGH: The resolution is the full 50 ps
LOW: The resolution is limited to 125 ns.
At low resolution no special arming and trig options are supported. There is no
handling of Abort messages from the bus after the measurement series has been
started. That means you cannot break off a low-resolution measurement series.
The results are based primarily on the timestamp values with 125-ns resolution.
Single mode is forced on, and every period of a signal is measured. This mode is
limited in frequency to <40 kHz for Frequency and Period, and <20 kHz for Time-
Interval and Pulse Width. At 40 kHz the resolution is 1/400, or 2.6 digits.
Returned format:
HIGH|LOW¿
*RST condition: HIGH
9-90 Command Reference
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PM6680B PM6681
:AVERage :COUNt
8 «<Decimal data>|MIN| MAX»
Average Samples
Sets the number of samples to use when doing time-interval averaging measure-
ments in :AVER:MODE 8 COUN. Applies to the functions:
PWIDTH, TIME, RISE and FALL TIME.
Parameters:
<Decimal data> is a number between 1and 65535.
Returned format: <Decimal data>¿
*RST condition: 100
Command Reference 9-91
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:AVERage :STATe
PM6680B/81/85
8 <Boolean>
Average or Single?
Switch on/off the average function.
Parameters: <Boolean> = 1 | ON / 0 | OFF
ON means multiple period measurements for period related measurements and time-interval av-
erage for Time-Interval measurements.
OFF means that the counter measures on a single cycle. This is the same as when pressing the
SINGLE key on the front panel.
When Single is selected and an array measurement is done, the Measurement
Time, set by :Acquisition:APERture, sets the time between the measure-
ments in the array. This means that if you want a very high speed yo must set
:AVER:STATE 8 OFF and :ACQ:APER 8 MIN.
Returned format: <Boolean>¿
*RST condition: ON
:FREQuency :RANGe :LOWer
PM6680B/PM6681
8 «<Numeric value>|MIN|MAX»
High Speed Voltage Measurements
Use this command to speed up voltage measurements and Autotrigger functions
when you don’t need to measure on low frequencies.
Time to determine trigger levels
Min frequency limit (Default)
Max frequency limit
PM6680B PM6681
30 ms
Measuring
function
PM6680B
PM6681
Freq A
48 ms
82 ms
85 ms
26 ms
38 ms
Time A-B
Parameters:
<Numeric value> for PM6680B, 100 gives the lower frequency limit of 100 Hz
and 10000 for a lower frequency limit of 10 kHz.
MIN gives 100 Hz frequency limit for PM6680B and 1Hz for PM6681.
MAX gives 10 kHz frequency limit forPM6680B and 50 kHz for PM6681.
Returned format:
<Numeric value>¿
*RST condition: 100
Complies to standards:
SCPI 1991.0, confirmed.
9-92 Command Reference
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PM6680B/81/85
:FUNCtion
8 ‘<Measuring function>[_<Primary channel> [,<Secondary channel>]]’
Select Measuring Function
Selects which measuring function is to be performed and on which channel(s) the
instrument should measure.
Parameters:
<Measuring function> is the function you want to select, according to the SENSe subsystem
<Primary channel> is the channel used in all single-channel measurements and the main chan-
nel in dual-channel measurements.
<Secondary channel> is the ‘other’ channel in dual-channel measurements. Only the primary
channel may be programmed for all single channel measurements.
The measuring function and the channels together form one <String> that must
be placed within quotation marks.
+
Example Select a pulse period measurement on input A (channel 1):
Send ® :FUNC 8 ‘PER 8 1’
Returned format: “<Measuring function>_<Primary channel>[,<Secondary channel>]”¿
*RST condition: FREQuency_1
Complies to standards:
SCPI 1991.0, confirmed.
n Functions and channels in PM6685
:FREQuency [ :CW ]
:FREQuency [ :CW ] :RATio
:FREQuency :BURSt
:FREQuency :PRFrequency
:PERiod
[ 8 ‘ 1 | 3 | 4 | 5 | 6 ‘ ]
[ 8 ‘ 1 | 3 | 4 , 1 | 3 | 4 ‘ ]
[ 8 ‘ 1 | 3 | 4 ‘ ]
[ 8 ‘ 1 | 3 | 4 ‘ ]
[ 8 ‘ 1 | 3 | 4 ‘ ]
[ 8 ‘ 1 | 4 ‘ ]
:NWIDth
:PWIDth
[ 8 ‘ 1 | 4 ‘ ]
:PDUTycycle | DCYCle
:NDUTycycle
:TOTalize [ :CONTinuous ]
[ 8 ‘ 1 | 4 ‘ ]
[ 8 ‘ 1 | 4 ‘ ]
[
8
‘ 0 | 1 | 4 , 0 | 1 | 4 ‘ ]
n Input channels PM6685
0
1
3
4
5
6
means that the input is disabled
means input A
means input C (HF-input option)
means input E (Rear panel arming input)
means input A prescaled by 2
means the internal reference
Command Reference 9-93
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n Functions and channels in PM6680B and PM6681
:FREQuency [ :CW ]
:FREQuency [ :CW ] :RATio
:FREQuency :BURSt
:FREQuency :PRF
[ 8 ‘ ( 1 | 2 3 | 4 | 5 | 6 | 7 ) ‘ ]
[ 8 ‘ 1 | 2 | 3 | 4 , 1 | 2 | 3 | 4 ‘ ]
[ 8 ‘ 1 | 2 | 3 | 4 | 5 | 6 | 7 ‘ ]
[ 8 ‘ 1 | 2 | 3 | 4 | 5 | 6 | 7 ‘ ]
:PERiod
[ 8 ‘ 1 | 2 | 3 | 4 | 5 | 6 | 7 ‘ ]
:TINTerval
:PHASe
[ 8 ‘ 1 | 2 | 4 , 1 | 2 | 4 | 6 ‘ ]
[ 8 ‘ 1 | 2 | 6 , 1 | 2 | 6 ‘ ]
:NWIDth
:PWIDth
[ 8 ‘ 1 | 2 | 4 | 6 ‘ ]
[ 8 ‘ 1 | 2 | 4 | 6 ‘ ]
:DCYCle | PDUTycycle
:NDUTycycl
[ 8 ‘ 1 | 2 | 4 | 6 ‘ ]
[ 8 ‘ 1 | 2 | 4 | 6 ‘ ]
:RISE:TIME
:FALL:TIME
[ 8 ‘ 1 | 2 ‘ ]
[ 8 ‘ 1 | 2 ‘ ]
:VOLT:MAXimum
:VOLT:MINimum
:VOLT:PTPeak
[ 8 ‘ 1 | 2 ‘ ]
[ 8 ‘ 1 | 2 ‘ ]
[ 8 ‘ 1 | 2 ‘ ]
:TOTalize:GATed
:TOTalize:TIMed
:TOTalize:ACCumulated
:TOTalize:SSTop
[ 8 ‘ 1 | 2 | 4 | 6, 1 | 2 | 4 | 6 ‘ ]
[ 8 ‘ 1 | 2 | 4 | 6, 1 | 2 | 4 | 6 ‘ ]
[ 8 ‘ 1 | 2 | 4 | 6, 1 | 2 | 4 | 6 ‘ ]
[ 8 ‘ 1 | 2 | 4 | 6 , 1 | 2 | 4 | 6 ‘ ]
n Input channels PM6680B and PM6681
1
2
3
4
5
6
7
means input A
means input B
means input C (HF-input option)
means input E (Rear panel arming input)
means input A prescaled by 2
means the internal reference
means input A with the variable hysteresis mode
9-94 Command Reference
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PM6680B/81/85
:INTernal :FORMat
«REAL|PACKed»
Internal Format
This command selects the internal data format of the measurement result from the
SENSe block. The purpose of the command is to increase the measurement
speed.
Parameters:
REAL means that the result is calculated in real-time after each measurement.
PACKed means that the raw measurement data is stored internally and the result is not calcu-
lated in real-time between measurements. The results are calculated later when they are
sent to the controller. Since the result is not calculated, other blocks cannot use this
data. That means that you cannot have the DISPlay, OUTPut, and CALCulate blocks
switched on when using PACKed format.
The following measuring functions in PM6680B/81 cannot be used with PACKed
format: Phase, Duty Cycle and Volt.
PM6685 cannot used PACKed format with Duty Cycle.
The internal format affects the number measuring results that the measurement re-
sult buffer can hold.
Number of Results in
Buffer
Format
Real:
Packed:
Measuring Function
All functions
PM6680B/85
2048
PM6681
7019
6143
4466
N.A.
Frequency, Period, Ratio Totalize
Pulse Width, Time-Interval, Rise/Fall time
Phase, Duty Cycle, Volt
2166
764
N.A.
Low resolution Frequency and Period
Low Res. Time-Interval and Pulse Width
N.A.
8191
4095
N.A.
You must consider this when fetching results with the :FETCh:ARRay query.
*RST condition: REAL
Command Reference 9-95
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:ROSCillator :SOURce
PM6680B/81/85
8 «INT|EXT»
Select Reference Oscillator
Selects the signal from the external reference input as timebase instead of the in-
ternal timebase oscillator.
Returned format: <INT|EXT>¿
*RST condition: INT
Complies to standards:
SCPI 1991.0, confirmed.
:SDELay
PM6685
8 «<Numeric value>|MIN|MAX»
BURST/PRF Synchronization Delay
Sets the synchronization delay time used in FREQuency:BURSt | PRF measure-
ments.
Parameter range: 200 ns to 1.6777215 s
*RST condition: 10 ms
9-96 Command Reference
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PM6680B/81/85
:TOTalize :GATE
8 <Boolean>
Gate On/Off
Open/closes the gate for :TOTalize[:CONTinuous].
Before opening the gate with this command, the counter must be in the ‘contin-
uously initiated’ state , (:INIT:CONT 8 ON)or else the totalizing will not start.
+
Parameters: <Boolean> = (1 / ON | 0 / OFF)
Returned format: <Boolean>¿
Example:
Send ® :FUNC 8 ‘TOT 8 1’
on input A
Selects totalizing
Send ® :INIT:CONT 8 ON;TOT:GATE 8 ON
This will initiate totalizing, reset the totalizing value to zero, and start totalizing.
Send ® TOT:GATE 8 OFF
Read ¬ :FETCh:ARRay? 8 -1
Stop totalizing
Read the final result
*RST condition: OFF
PM6680B PM6681
:VOLTage:GATed:STATe
8 <Boolean>
Gated Voltage Measurement
Selects the gated mode for the :VOLTage:MAX|MIN|PTPeak measuring func-
tions and for the Autotrigger function.
The gated mode is useful for removing overshoot and undershoot. The gate signal
is controlled by the :ARM:STOP:SLOPe and :ARM:STOP:SOURce commands. If
channel 2 (B) is the source for the gating signal, all other characteristics of that
channel can be used. When Gated Voltage is selected, the Stop Arming function is
disabled from its normal stop arming usage. When gated voltage mode is selected,
high enables measurement and low disables measurements. Use the slope if you
want it the other way around.
Parameters:
<Boolean> = 1/ON|0/OFF
Returned format:
1|0 ¿
*RST condition: OFF
Command Reference 9-97
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Status Subsystem
:STATus
:DREGister0
:ENABle
[:EVENt]?
8
8
8
<bit mask>
<bit mask>
<bit mask>
:OPERation
:CONDition?
:ENABle
[:EVENt]?
:QUEStionable
:CONDition?
:ENABle
[:EVENt]?
:PRESet
n Related Common Commands:
*CLS
*ESE
*ESR?
8
<bit mask>
*PSC
*SRE
*STB?
8
8
<bit mask>
<bit mask>
Command Reference 9-99
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:STATus :DREGister0?
80B/81/85
Read Device Status Event Register
This query reads out the contents of the Device Event Register. Reading the De-
vice Event Register clears the register. See Figure 6-14.
Returned format:
<dec.data> = the sum (between 0 and 6) of all bits that are true. See table below:
Bit No.
Weight
Condition
2
1
4
2
Last measurement below low limit.
Last measurement above high limit.
:STATus :DREGister0 :ENABle
80B/81/85
8 <bit mask>
Enable Device Status Reporting
This command sets the enable bit of the Device Register 0.
Parameters:
<dec.data> = the sum (between 0 and 6) of all bits that are true. See table below:
Bit No.
Weight
Condition
2
1
4
2
Enable monitoring of low limit
Enable monitoring of high limit
Returned format: <bit mask>¿
9-100 Command Reference
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:STATus :OPERation :CONDition?
80B/81/85
Read Operation Status Condition Register
Reads out the contents of the operation status condition register. This register re-
flects the state of the measurement process. See figure below. Note that bits 0 to
3, 7, and 9 to 15 are not used.
Returned Format:
<Decimal data> = the sum (between 0 and 368) of all bits that are true. See table below:
Bit No.
Weight
256
64
Condition
Not Measurement
8
6
5
4
Waiting for bus arming
Waiting for triggering and/ or external arming
Measurement
32
16
Complies to standards:
SCPI 1991.0, confirmed
Command Reference 9-101
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:STATus :OPERation :ENABle
80B/81/85
8 <Decimal data>
Enable Operation Status Reporting
Sets the enable bits of the operation status enable register. This enable register
contains a mask value for the bits to be enabled in the operation status event reg-
ister. A bit that is set true in the enable register enables the corresponding bit in
the status register. See figure on page 9-101.
An enabled bit will set bit #7, OPR (Operation Status Bit), in the Status Byte Regis-
ter if the enabled event occurs. See also status reporting on page 3-14.
Power-on will clear this register if power-on clearing is enabled via *PSC.
Parameters: <dec.data> = the sum (between 0 and 368) of all bits that are true. See ta-
ble below:
Bit No.
Weight
256
64
Condition
No measurement
8
6
5
4
Waiting for bus arming
Waiting for triggering and/or external arming
Measurement
32
16
Returned Format: <Decimal data>¿
Example:
SEND® :STAT:OPER:ENAB 8 288
In this example, waiting for triggering, bit 5, and Measurement stopped, bit 8, will
set the OPR-bit of the Status Byte. (This method is faster than using *OPC if you
want to know when the measurement is ready.)
Complies to standards:
SCPI 1991.0, confirmed.
9-102 Command Reference
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:STATus:OPERation?
80B/81/85
Read Operation Status, Event
Reads out the contents of the operation event status register. Reading the Opera-
tion Event Register clears the register. See figure on page 9-101.
Returned Format: <Decimal data>¿
<dec.data> = the sum (between 0 and 368) of all bits that are true. See table on page 9-102.
Complies to standards:
SCPI 1991.0, confirmed.
PM6680B/81/85
:STATus :PRESet
Enable Device Status Reporting
This command has an SCPI standardized effect on the status data structures. The
purpose is to precondition these toward reporting only device-dependent status
data.
– It only affects enable registers. It does not change event and condition registers.
– The IEEE-488.2 enable registers, which are handled with the common commands *SRE and
*ESE remain unchanged.
– The command sets or clears all other enable registers. Those relevant for this counter are as
follows:
– It sets all bits of the Device status Enable Registers to 1.
– It sets all bits of the Questionable Data Status Enable Registers and the Operation Status En-
able Registers to 0.
– The following registers never change in the counter, but they do conform to the standard
:STATus:PRESet values.
– All bits in the positive transition filters of Questionable Data and Operation status registers
are 1.
– All bits in the negative transition filters of Questionable Data and Operation status registers
are 0.
Complies to standards:
SCPI 1991.0, confirmed.
Command Reference 9-103
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:STATus :QUEStionable :CONDition?
PM6680B/81/85
Read Questionable Data/Signal Condition Register
Reads out the contents of the status questionable condition register.
Returned Format:
<dec.data> = the sum (between 0 and 17920) of all bits that are true. See table below:
Bit No.
14
Weight
Condition
16384
Unexpected parameter
10
9
1024
512
Timeout or no signal detected
Overflow
Complies to standards:
SCPI 1991.0, confirmed.
9-104 Command Reference
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:STATus :QUEStionable :ENABle
PM6680B/81/85
8 <Decimal data>
Enable Questionable Data/Signal Status Reporting
Sets the enable bits of the status questionable enable register. This enable register
contains a mask value for the bits to be enabled in the status questionable event
register. A bit that is set true in the enable register enables the corresponding bit in
the status register. See figure on page 9-104.
An enabled bit will set bit #3, QUE (Questionable Status Bit), in the Status Byte
Register if the enabled event occurs. See also status reporting on page 3-14.
Power-on will clear this register if power-on clearing is enabled via *PSC.
Parameters:
<dec.data> = the sum (between 0 and 17920) of all bits that are true. See the table on page
Returned Format: <Decimal data> ¿
Example:
:STAT:QUES:ENAB 8 16896
Send ®
In this example, both ‘unexpected parameter’ bit 14, and ‘overflow’ bit 8, will set
the QUE-bit of the Status Byte when a questionable status occurs.
Complies to standards:
SCPI 1991.0, confirmed.
:STATus :QUEStionable?
PM6680B/81/85
Read Questionable Data/Signal Event Register
Reads out the contents of the status questionable event register. Reading the
Status Questionable Event Register clears the register. See figure on page 9-104.
Returned Format:
<dec.data> = the sum (between 0 and 17920) of all bits that are true. See the table on page
Complies to standards:
SCPI 1991.0, confirmed.
Command Reference 9-105
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System Subsystem
:SYSTem
:COMMunicate
:GPIB
:ADDRess
8
8
<Numeric value> | MIN | MAX
ON | OFF
:ERRor?
:PRESet
:SYSTem:SDETect[:ENABle]
:SET
:TIME
(Only PM6685)
8
<Block data>
:ELAPsed?
:TOUT
[:STATe]
8
ON | OFF
8
:TIME
:UNPRotect
<timeout value>
:VERSion?
n Related common command:
*IDN?
*OPT?
*PUD 8 <arbitrary block program data>
*RST
Command Reference 9-107
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:SYSTem :COMMunicate: GPIB: ADDRess
80B/81/85
8 «<Numeric value>|MAX|MIN» [,«<Numeric value>|MAX|MIN»]
Set GPIB Address
This command sets the GPIB address. This selection overrides the switches on
the rear panel of the counter. The set address is valid until a new address is set,
either by bus command, switch setting, or via the front panel AUX-MENU.
Parameters:
<Numeric value> is a number between 0 and 30.
MIN sets address 0.
MAX sets address 30.
[,<Numeric value>|MAX|MIN] sets a secondary address. This is accepted but not
used in PM6681 and PM6685. PM6680B does not accept a secondary address.
[:SELF] 8 This optional parameter is accepted by PM6681 and PM6685.
PM6680B does not accept [:SELF].
Returned format:> <Numeric value>¿
Example:
SEND® :SYST:COMM:GPIB:ADDR 8 12
This example sets the bus address to 12.
Complies to standards:
SCPI 1991.0, confirmed.
:SYSTem :ERRor?
PM6680B/81/85
Queries for an ASCii text description of an error that occurred. The error mes-
sages are placed in an error queue, with a FIFO (First In-First Out) structure. This
queue is summarized in the Error AVailable (EAV) bit in the status byte.
Returned format:
<error number>,"<Error Description String>"¿
Where:
<Error Description String> = an error description as ASCii text.
Complies to standards:
SCPI 1991.0, confirmed.
9-108 Command Reference
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PM6680B/81/85
:SYSTem :PRESet
Preset
This command sets the counter to the same default settings as when the front
panel key LOCAL/PRESET is pressed in local mode.
These are not exactly the same settings as after *RST,
SYST:PRES gives 200 ms Measurement Time and signal detection ON, while
*RST gives 10-ms Measurement Time and signal detection OFF.
+
See also: Default settings on page -.
Complies to standards:
SCPI 1991.0, confirmed.
PM6685
:SYSTem :SDETect
8 <Boolean>
Signal Detection
This command switches on or off the signal detection, that is, the ability to show
NO SIGNAL, NO TRIG on the display.
When signal detection is enabled, the measurement attempt will be abandoned
when the no signal is detected. A zero result will be sent to the controller instead of
a measurement result, and the timeout bit in the STATus QUEStionable register
will be set.
Returned format: «0|1»¿
Where:
0 means no signal detection
1 means signal detection ON.
*RST condition:
0
Command Reference 9-109
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:SYSTem :SET
PM6680B/81/85
8 <Block data>
Read or Send Settings
Transmits in binary form the complete current state of the instrument. This data
can be sent to the instrument to later restore this setting. This command has the
same function as the *LRN? common command with the exception that it returns
the data only as response to :SYST:SET?. The query form of this command re-
turns a definite block data element.
Parameters:
<Block data> is the instrument setting previously retrieved via the :SYSTem:SET? query.
Returned format: <Block data>¿
Where:
<Block data> is #292<92 data bytes> for PM6680B
<Block data> is #3104<104 data bytes> for PM6681
<Block data> is #276<76 data bytes> for PM6685
SEND® :SYST:SET?
READ¬ #2764...-8 .8 .Çä......d...8
+.................-.c-..............8 8 ?..............d
Complies to standards:
SCPI 1991.0, confirmed.
:SYSTem :TIME :ELAPsed?
PM6680B/81/85
Read On-time
Use this command if you want to know (in seconds) how long the counter has
been on.
Returned format:
<String>=Power-on time.
For PM6680B and PM6685, this is the time elapsed since the last power-on.
For PM6681, this is the total elapsed time since the counter was new.
9-110 Command Reference
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PM6680B/81/85
:SYSTem :TOUT
8 <Boolean>
Timeout On/Off
This command switches on or off the timeout. When timeout is enabled, the mea-
surement attempt will be abandoned when the time set with :SYST:TOUT:TIME
has elapsed. A zero result will be sent to the controller instead of a measurement
result and the timeout bit in the STATus QUEStionable register will be set.
Returned format: 0 means no timeout; 1 means that the timeout set by :SYS-
Tem:TOUT:TIME is used.
Example:
SEND® :SYST:TOUT 8 1;TOUT:TIME 8 0.5;:STAT:QUES:ENAB 8
1024;:*SRE 8 8
This example turns on timeout, sets the timeout to 0.5 s, enables status reporting of
questionable data at timeout, and enables service request on questionable data.
SEND® *STB?
questionable data status.
SEND® :STAT:QUES:EVEN?
tionable data status.
If bit 3 in the status byte is set, read the
This query reads the ques-
READ¬ «1024|0»
means no timeout.
1024 means timeout has occurred, and 0
*RST condition:
0
PM6680B/81/85
:SYSTem :TOUT :TIME
8 «<Numeric value>|MIN|MAX»
Timeout, Set
This command sets the timeout in seconds.
The timeout starts when a measurement starts and, if no result is obtained when
the set timeout has elapsed the measurement is terminated.
Note that you must enable timeout using :SYST:TOUT_ON for this setting to take
effect.
Parameters:
<Numeric value> is the timeout in seconds. The range is 0.1 to 25.5 s for PM6680B and
PM6685. The range is 64 ms to 400 s for PM6681
MIN gives 0.1 s (64 ms for PM6681)
MAX gives 25.5 s (400 s for PM6681)
Returned format: <Numeric value>¿
*RST condition: 0.1 (6.4E-2 for PM6681)
Complies to standards:
SCPI 1991.0, confirmed.
Command Reference 9-111
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:SYSTem :UNPRotect
PM6680B/81/85
Unprotect
This command will unprotect the user data (set/read by *PUD) and front setting
memories 10-19 until the next PMT (Program message terminator) or Device clear
or Reset (*RST). This makes it necessary to send an unprotect command in the
same message as for instance *PUD.
Example
Send ® :SYST:UNPR; *PUD 8 #240Calibrated 8 1992-11-17, 8 inven-
tory No.1234
Where:
# means that <arbitrary block program data> will follow.
2 means that the two following digits will specify the length of the data block
40 is the number of characters in this example
:SYSTem :VERSion?
PM6680B/81/85
System Version
This query returns the SCPI system version that this instrument complies to.
Returned format:
<year>.<revision>¿
Where <year> is the year of publication of the complied standard and <revision> is
the number of the SCPI standard.
Example
Send ® :SYST:VER?
Read¬ 1991.0
Complies to standards:
SCPI 1991.0, confirmed.
9-112 Command Reference
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:TEST:CHECk
PM6680B/81/85
8 <Boolean>
Select Check signal
This command connects the internal reference signal to the measuring logic, in-
stead of an external measuring signal. This makes it possible to test all functions.
The frequency of the reference is 10 MHz for PM6680B and PM6685, and
100 MHz for PM6681.
Parameters:
<Boolean> = 1 / ON | 0 / OFF
1 and ON means test signal connected
0 and OFF means test signal disconnected.
Selecting channel 6 when entering measuring channel for :CONFigure :MEA-
Sure, etc., also selects the reference.
+
*RST condition:
Returned format: 1|0¿
0
:TEST :SELect
PM6680B/81/85
8 «RAM | ROM | LOGic | DISPlay | ALL»
Select Self-tests
Selects which internal self-tests shall be used when self-test is requested by the
*TST command.
Returned format:
«RAM | ROM | LOGic | DISPlay | ALL»¿
*RST condition: ALL
9-114 Command Reference
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:TRIGger:COUNt
PM6680B/81/85
8 «<Numeric value> | MIN | MAX»
No. of Triggerings on each Ext Arm start
Sets how many measurements the instrument should make for each ARM:STARt
condition, (block arming).
These measurements are done without any additional arming conditions before
the measurement. This also means that stop arming is disabled for the measure-
ments inside a block.
The actual number of measurements made on each INIT equals to:
(:ARM:START:COUN)*(:TRIG:START:COUNT)
+
<Numeric value> is a number between 1 and 65535.
Parameters:
MAX gives 65535
MIN gives 1
Example:
SEND® :TRIG:COUN 8 50
Returned format: <Numeric value>¿
*RST condition:
1
Complies to standards:
SCPI 1991.0, confirmed.
9-116 Command Reference
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Common Commands
*CLS
*DMC
*EMC
*ESE
8
8
8
<Macro label> , <Program messages>
<Decimal data>
<Decimal data>
*ESR?
*GMC?
*IDN?
8
<Macro label>
*LMC?
*LRN?
*OPC
*OPC?
*OPT?
*PMC
*PSC
*PUD
*RCL
*RMC
*RST
8
8
8
8
<Decimal data>
<Arbitrary block program data>
<Decimal data>
<Macro name>
*SAV
*SRE
*STB?
8
8
<Decimal data>
<Decimal data>
*TRG
*TST?
*WAI
Command Reference 9-117
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*CLS
PM6680B/81/85
Clear Status Command
The *CLS common command clears the status data structures by clearing all event
registers and the error queue. It does not clear enable registers and transition fil-
ters. It clears any pending *WAI, *OPC, and *OPC?.
Example:
*CLS
Send ®
Complies to standards:
IEEE 488.2 1987.
9-118 Command Reference
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PM6680B/81/85
*DMC
8 <Macro label> , <Program messages>
Define Macro
Allows you to assign a sequence of one or more program message units to a
macro label. The sequence is executed when the macro label is received as a
command or query. Twenty five macros can be defined at the same time, and each
macro can contain an average of 40 characters.
If a macro has the same name as a command, it masks out the real command with
the same name when macros are enabled. If macros are disabled, the original
command will be executed.
If you define macros when macro execution is disabled, the counter executes the
*DMC command fast, but if macros are enabled, the execution time for this com-
mand is longer.
Parameters:
<Macro label> = 1 to 12-character macro label. (String data must be surrounded by “ ” or ‘ ‘
as in the example below.)
<Program messages> = the commands to be executed when the macro label is received, both
block data and string data formats can be used.
Example 1:
SEND® *DMC ‘AMPLITUDE?’,":FUNC 8 ‘FREQ 8 1’;:INP:HYST:AUTO ONCE
8 ;:INP:HYST?;:INP:LEV?"
This example defines a macro called amplitude?.
SEND® AMPLITUDE?
The macro makes an AUTO ONCE and reads out the hysteresis and trigger level
that auto selects. (Macros must be enabled; otherwise, the :AMPLITUDE? query
will not execute, see *EMC)).
READ¬ +3.46125461E-001;+3.64852399E-001
Auto selects 33% of Vpp as hysteresis, so multiplying the first part of this reading
by 3 will give you the signal amplitude (0.346*3=1.04 V in this example). You can
Hysteresis * 3
also calculate positive peak voltage:
+Trigger Level and negative
2
Hysteresis * 3
peak voltage: Vp
- Trigger Level
2
Example 2:
SEND® *DMC 8 ‘AUTOFILT’,":INP:HYST:AUTO 8 $1;:INP:FILT 8 $1
This example defines a macro AUTO which takes one argument, i.e., auto
«ON|OFF|ONCE» ($1) .
SEND® AUTOFILT 8 OFF
Turns off both the auto function and the filter.
Complies to standards:
IEEE 488.2 1987.
Command Reference 9-119
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*EMC
PM6680B/81/85
8 <Decimal data>
Enable Macros
This command enables and disables expansion and execution of macros. If mac-
ros are disabled, the instrument will not recognize a macro although it is defined in
the instrument. (The Enable Macro command takes a long time to execute.)
Parameters:
<Decimal data> = is 0 or 1. A value which rounds to 0 turns off macro execution. Any other
value turns macro execution on.
Note that 1 or 0 is <Decimal data>, not <Boolean>!
ON|OFF is not allowed here!
+
Returned format: «0|1» ¿
1 indicates that macro expansion is enabled.
0 indicates that macro expansion is disabled.
Example:
*EMC 8 1
SEND®
Enables macro expansion and execution.
Complies to standards:
IEEE 488.2 1987.
9-120 Command Reference
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*ESE
PM6680B/81/85
8 <Decimal data>
Standard Event Status Enable
Sets the enable bits of the standard event enable register. This enable register
contains a mask value for the bits to be enabled in the standard event status regis-
ter. A bit that is set true in the enable register enables the corresponding bit in the
status register. An enabled bit will set the ESB (Event Status Bit) in the Status Byte
Register if the enabled event occurs. See also status reporting on page 3-14.
Parameters: <dec.data> = the sum (between 0 and 255) of all bits that are true.
Event Status Enable Register (1 = enable)
Bit
7
Weight
Enables
128
64
32
16
8
PON, Power-on occurred
URQ, User Request
CME, Command Error
EXE, Execution Error
DDE, Device Dependent Error
QYE, Query Error
6
5
4
3
2
4
1
2
RQC, Request Control (not used)
Operation Complete
0
1
Returned Format: <Decimal data> ¿
Example:
SEND® *ESE 8 36
In this example, command error, bit 5, and query error, bit 2, will set the ESB-bit of
the Status Byte if these errors occur.
Figure 9-3
Bits in the standard event status register.
Complies to standards:
IEEE 488.2 1987.
Command Reference 9-121
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∗ESR?
PM6680B/81/85
Event Status Register
Reads out the contents of the standard event status register. Reading the Stan-
dard Event Status Register clears the register.
Returned Format:
<dec.data> = the sum (between 0 and 255) of all bits that are true. See table on page 9-121.
Complies to standards:
IEEE 488.2 1987.
*GMC?
PM6680B/81/85
8 < macro label>
Get Macro Definition
This command makes the counter respond with the current definition of the given
macro label.
Parameters:
<Macro label> = the label of the macro for which you want to see the definition. (String data
must be surrounded by “ ” or ‘ ‘ as in the example below.)
Returned Format: <Block data>¿
Example:
SEND® *GMC? 8 ‘AMPLITUDE?’
Gives a block data response, for instance:
READ¬
#255:FUNC ‘FREQ 1’;:INP:HYST:AUTO ONCE;:INP:HYST?;INP:LEV?
Complies to standards:
IEEE 488.2 1987.
9-122 Command Reference
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PM6680B/81/85
*IDN?
Identification query
Reads out the manufacturer, model, serial number, Firmware level for main and
GPIB program in an ASCii response data element. The query must be the last
query in a program message.
Response is <Manufacturer> , <Model> , <Serial Number>, <Firmware Level>.
<Serial number> is not implemented in PM6680B and PM6685 and will always re-
turn a zero. Please look at the type plate at the rear panel of the counter if you are
interested in the serial number. PM6681 returns the correct serial number.
Example
SEND ®*IDN?
READ¬ Fluke, 8 8 8 8 PM6685, 8 0, 8 MAIN 8 V1.01 8 19 Nov 8
1992 8 / 8 GPIB 8 V1.12 8 8 28 8 Oct 8 1992
Complies to standards:
IEEE 488.2 1987.
PM6680B/81/85
*LMC?
Learn Macro
Makes the instrument send a list of string data elements, containing all macro la-
bels defined in the instrument.
Returned Format:
<String> { ,<String> }¿
<String> = a Macro label. (String data will be surrounded by “ ” as in the example below.)
Example:
SEND® *LMC?
May give the following response:
“AUTOFILT”,"AMPLITUDE?"
READ¬
Complies to standards:
IEEE 488.2 1987.
Command Reference 9-123
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*LRN?
PM6680B/81/85
Learn Device Setup
Learn Device Setup Query. Causes a response message that can be sent to the
instrument to return it to the state it was in when the *LRN? query was made.
Returned Format:
:SYST:SET_<Block data>¿
Where:
<Block data> is #292<92 data bytes> for PM6680B
<Block data> is #3104<104 data bytes> for PM6681
<Block data> is #276<76 data bytes> for PM6685
Example
SEND® *LRN?
Complies to standards:
IEEE 488.2 1987.
*OPC
PM6680B/81/85
Operation Complete
The Operation Complete command causes the device to set the operation com-
plete bit in the Standard Event Status Register when all pending selected device
operations have been finished. See also Example 4 in Chapter 4.
Example:
Enable OPC-bit
SEND® *ESE 8 1
Start measurement (INIT). *OPC will set the operation complete bit in the status register when the
measurement is done.
SEND® :INIT;*OPC
Wait 1s for the measurement to stop. Read serial poll register, will reset service request
SPOLL
Check the Operation complete bit (0) in the serial poll byte. If it is true the measurement is
completed and you can fetch the result.
SEND® FETCh?
Then read the event status register to reset it:
SEND® *ESR?
If bit 0 is false, abort the measurement.
SEND® :ABORt
Complies to standards:
IEEE 488.2 1987.
9-124 Command Reference
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PM6680B/81/85
*OPC?
Operation Complete Query
Operation Complete query. The Operation Complete query places an ASCii char-
acter 1 into the device’s Output Queue when all pending selected device opera-
tions have been finished.
Returned Format: 1¿
See also:
Example 6 is Chapter 4.
Complies to standards:
IEEE 488.2 1987.
PM6680B/81/85
*OPT?
Option Identification
Response is a list of all detectable options present in the instrument, with absent
options represented with an ASCii ‘0’.
Returned format:
<Bus option>,<Prescaler option>¿
Where:
<Bus option> = GPIB
<Prescaler option> = 0|10|20
0 for prescaler option means that no prescaler is installed.
Oscillator type are not detectable and can therefore, not be reported.
+
Complies to standards:
IEEE 488.2 1987.
Command Reference 9-125
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*PMC
PM6680B/81/85
Purge Macros
Removes all macro definitions.
Example: *PMC
See also:
:MEMory:DELete:MACRo 8 ‘<Macro-name>’ if you want to remove a single
macro.
Complies to standards:
IEEE 488.2 1987.
*PSC
PM6680B/81/85
8 <Decimal data>
Power-on Status Clear
Enables/disables automatic power-on clearing. The status registers listed below
are cleared when the power-on status clear flag is 1. Power-on does not affect the
registers when the flag is 0.
– Service request enable register (*SRE)
– Event status enable register (*ESE)
– Operation status enable register (:STAT:OPER:ENAB)
– Questionable data/signal enable register (:STAT:QUES:ENAB)
– Device enable registers (:STAT:DREG0:ENAB)
– *RST does not affect this power-on status clear flag.
Parameters: <Decimal data> = a number that rounds to 0 turns off automatic power-on
clearing. Any other value turns it on.
Returned Format: «1 | 0» ¿
1 is enabled and 0 is disabled.
Example: *PSC 8 1
This example enables automatic power-on clearing.
Complies to standards:
IEEE 488.2 1987.
9-126 Command Reference
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PM6680B/81/85
*PUD
8 <Arbitrary block program data>
Protected User Data
Protected user data. This is a data area in which the user may write any data up to
64 characters. The data can always be read, but you can only write data after un-
protecting the data area. A typical use would be to hold calibration information, us-
age time, inventory control numbers, etc.
The content at delivery is: #234 FACTORY CALIBRATED ON: 19YY-MM-DD
– YY = year, MM = month, DD = day
Returned format: <Arbitrary block response data>¿
– Where:
<arbitrary block program data> is the data last programmed with *PUD.
Example
Send ® :SYST:UNPR; *PUD 8 #240Calibrated 8 1993-07-16, 8 inven-
tory 8 No.1234
# means that <arbitrary block program data> will follow.
2 means that the two following digits will specify the length of the data block.
40 is the number of characters in this example.
Complies to standards:
IEEE 488.2 1987.
PM6680B/81/85
*RCL
8 <Decimal data>
Recall
Recalls one of the up to 20 previously stored complete instrument settings from the
internal nonvolatile memory of the instrument.
Memory number 0 contains the power-off settings for PM6685. For PM6681 mem-
ory number 0 contains the power-off settings until PRESET is pressed. After pre-
set, memory 0 contains the pre-preset settings.
Parameters:
<Decimal data> = a number between 0 and 19.
Example:
SEND® *RCL 8 10¿
Complies to standards:
IEEE 488.2 1987.
Command Reference 9-127
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PM6680B/81/85
∗RMC
8 ‘<Macro name>’
Delete one Macro
This command removes an individual MACRo.
Parameters:
‘<Macro name>’ is the name of the macro you want to delete.
<Macro name> is String data that must be surrounded by quotation marks.
+
See also:
*PMC, if you want to delete all macros.
*RST
PM6680B/81/85
Reset
The Reset command resets the counter. It is the third level of reset in a 3-level re-
set strategy, and it primarily affects the counter functions, not the IEEE 488 bus.
The counter settings will be set to the default settings listed on page -. All previous
commands are discarded, macros are disabled, and the counter is prepared to
start new operations.
Example: *RST
See also:
Default settings on page -.
Complies to standards:
IEEE 488.2 1987.
9-128 Command Reference
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PM6680B/81/85
*SAV
_ <Decimal data>
Save
Saves the current settings of the instrument in an internal nonvolatile memory.
Nineteen memory locations are available. Switching the power off and on does not
change the settings stored in the registers.
Note that memory positions 10 to 19 can be protected from the front panel auxiliary
menu. If this has been done, use the :SYSTem:UNPRotect command, then you
can alter these memory positions.
Parameters
<Decimal data> = a number between 1 and 19.
Example:
SEND® *SAV 8 10¿
Complies to standards:
IEEE 488.2 1987
Command Reference 9-129
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*SRE
PM6680B/81/85
8 <Decimal data>
Service Request Enable
The Service Request Enable command sets the service request enable register
bits. This enable register contains a mask value for the bits to be enabled in the
status byte register. A bit that is set true in the enable register enables the corre-
sponding bit in the status byte register to generate a Service Request.
Parameters: <dec.data> = the sum (between 0 and 255) of all bits that are true.
See table below:
Service Request Enable Register (1 = enable)
Bit
Weight
Enables
7
6
5
4
3
2
1
0
128
64
32
16
8
OPR, Operation Status
RQS, Request Service
ESB, Event Status Bit
MAV, Message Available
QUE, Questionable Data/Signal Status
EAV, Error Available
Not used
4
2
1
Device Status
Returned Format: <Integer>¿
Where:
<Integer> = the sum of all bits that are set.
Example: *SRE 8 16
In this example, the counter generates a service request when a message is avail-
able in the output queue.
Complies to standards:
IEEE 488.2 1987.
9-130 Command Reference
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PM6680B/81/85
*STB?
Status Byte Query
Reads out the value of the Status Byte. Bit 6 reports the Master Summary Status
bit (MSS), not the Request Service (RQS). The MSS is set if the instrument has
one or more reasons for requesting service.
Returned Format:
<Integer> = the sum (between 0 and 255) of all bits that are true. See table below:
Status Byte Register (1 = true)
Bit
Weight
Name
Condition
7
6
5
4
3
2
1
0
128
64
32
16
8
OPR
MSS
ESB
MAV
QUE
EAV
Enabled operation status has occurred.
Reason for requesting service
Enabled status event condition has occurred
An output message is ready
The quality of the output signal is questionable
Error available
4
2
Not used
1
DREG0
Enabled status device event conditions have
occurred
See also: If you want to read the status byte with the RQS bit, use serial poll.
Complies to standards:
IEEE 488.2 1987.
PM6680B/81/85
*TRG
Trigger
The trigger command *TRG starts the measurement and places the result in the
output queue.
It is the same as:
:ARM:STARt:LAYer2:IMM; *WAI;:FETCh?
The Trigger command is the device-specific equivalent of the IEEE 488.1 defined
Group Execute Trigger, GET. It has exactly the same effect as a GET after it has
been received, and parsed by the counter.
However, GET is much faster than *TRG, since GET is a hardware signal that does
not have to be parsed by the counter.
Example:
SEND® :ARM:START:LAY2:SOURCE 8 BUS
SEND® :INIT:CONT 8 ON
SEND® *TRG
READ¬ +3.2770536E+004
Type of Command:
Aborts all previous measurement commands if not *WAI is used.
Complies to standards:
IEEE 488.2 1987.
Command Reference 9-131
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*TST?
PM6680B/81/85
Self Test
The self-test query causes an internal self-test and generates a response indicat-
ing whether or not the device completed the self-test without any detected errors.
Returned Format: <Integer>¿
Where:
<Integer> = a number indicating errors according to the table below.
PM6680B Error
PM6681, PM6685 Er-
ror
<Integer> =
0
1
2
4
8
No error
RAM Failure
ROM 1 Failure
Logic Failure
Display Failure
Not used
Display Failure
Logic Failure
RAM Failure
Bus ROM Failure
ROM Bank 1 Failure
ROM Bank 2 Failure
16
32
Not used
Complies to standards:
IEEE 488.2 1987
*WAI
PM6680B/81/85
Wait-to-continue
The Wait-to-Continue command prevents the device from executing any further
commands or queries until execution of all previous commands or queries has
been completed.
Example:
:MEAS:FREQ?; *WAI;:MEAS:PDUT?
SEND®
In this example, *WAI makes the instrument perform both the frequency and the
Duty Cycle measurement. Without *WAI, only the Duty Cycle measurement would
be performed.
READ¬ +5.1204004E+002;+1.250030E-001
Complies to standards:
IEEE 488.2 1987.
9-132 Command Reference
Download from Www.Somanuals.com. All Manuals Search And Download.
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