National Instruments Car Stereo System 320571 01 User Manual
™
NI-DSP  
Software Reference Manual  
®
for LabVIEW for Windows  
Digital Signal Processing Software for the PC  
December 1993 Edition  
Part Number 320571-01  
© Copyright 1993 National Instruments Corporation.  
All Rights Reserved.  
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Contents  
About This Manual  
....................................................................................................................xi  
Assumption of Previous Knowledge ........................................................................................................xi  
Organization of This Manual ....................................................................................................................xi  
Conventions Used in This Manual............................................................................................................xii  
Related Documentation ............................................................................................................................xiv  
Additional Software ..................................................................................................................................xiv  
NI-DAQ for DOS/Windows/LabWindows ................................................................................xiv  
Developer Toolkit ......................................................................................................................xv  
Compatible Hardware............................................................................................................................... xv  
Customer Communication ........................................................................................................................xv  
Part 1  
Getting Started with NI-DSP  
........................................................................................1-1  
Product Overview ..................................................................................................................................... 1-1  
The NI-DSP Software............................................................................................................................... 1-1  
What Your Distribution Diskettes Should Contain ....................................................................1-2  
Installing NI-DSP for LabVIEW for Windows ........................................................................................1-2  
Board Configuration ................................................................................................................................. 1-3  
Installation on an ISA (or AT) Bus Computer ........................................................................... 1-3  
Installation on an EISA Bus Computer ......................................................................................1-3  
Part 2  
Introduction to the NI-DSP Analysis VIs  
....................................................1-1  
Using the NI-DSP VIs in LabVIEW ........................................................................................................1-1  
AT-DSP2200 Software Overview ............................................................................................................1-1  
Memory Management and Data Transfer................................................................................................. 1-2  
Special Features of the NI-DSP Analysis VIs ..........................................................................................1-5  
Hints for Improving the Execution Speed on the DSP Board ....................................................1-7  
An Example of Using NI-DSP Analysis VIs............................................................................................1-8  
Part 3  
NI-DSP Function Reference  
Chapter 1  
NI-DSP Analysis VI Reference Overview............................................................................... 1-1  
The NI-DSP Analysis VI Overview ......................................................................................................... 1-1  
Analysis VI Organization ......................................................................................................................... 1-3  
Accessing the NI-DSP Analysis VIs ........................................................................................................1-3  
About the Fast Fourier Transform (FFT)..................................................................................................1-4  
About Filtering..........................................................................................................................................1-5  
About Windowing ....................................................................................................................................1-6  
Chapter 2  
NI-DSP Analysis VI Reference........................................................................................................2-1  
Copy Mem(DSP to DSP) ..........................................................................................................................2-1  
Copy Mem(DSP to LV) ............................................................................................................................2-2  
Copy Mem(LV to DSP) ............................................................................................................................2-3  
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Contents  
DSP Absolute............................................................................................................................................2-4  
DSP Add ................................................................................................................................................... 2-5  
DSP Allocate Memory..............................................................................................................................2-6  
DSP Blackman Window ........................................................................................................................... 2-7  
DSP Blackman Harris Window ................................................................................................................2-8  
DSP Butterworth Coefficients ..................................................................................................................2-9  
DSP Chebyshev Coefficients....................................................................................................................2-10  
DSP Clip ................................................................................................................................................... 2-11  
DSP Complex FFT....................................................................................................................................2-12  
DSP Convolution ......................................................................................................................................2-13  
DSP Correlation ........................................................................................................................................2-14  
DSP Cross Power......................................................................................................................................2-15  
DSP Custom..............................................................................................................................................2-16  
DSP Decimate........................................................................................................................................... 2-17  
DSP Deconvolution ..................................................................................................................................2-18  
DSP Derivative ......................................................................................................................................... 2-19  
DSP Divide ............................................................................................................................................... 2-20  
DSP Elliptic Coefficients..........................................................................................................................2-21  
DSP Equi-Ripple Bandpass ......................................................................................................................2-23  
DSP Equi-Ripple Bandstop ......................................................................................................................2-25  
DSP Equi-Ripple HighPass ......................................................................................................................2-27  
DSP Equi-Ripple LowPass ....................................................................................................................... 2-29  
DSP Exact Blackman Window................................................................................................................. 2-30  
DSP Exponential Window ........................................................................................................................2-31  
DSP FHT ..................................................................................................................................................2-32  
DSP Flat Top Window..............................................................................................................................2-33  
DSP Force Window ..................................................................................................................................2-34  
DSP Free Memory ....................................................................................................................................2-34  
DSP Gaussian White Noise ......................................................................................................................2-35  
DSP General Cosine Window ..................................................................................................................2-36  
DSP Hamming Window ........................................................................................................................... 2-37  
DSP Handle to Address ............................................................................................................................2-38  
DSP Hanning Window..............................................................................................................................2-39  
DSP IIR Filter ........................................................................................................................................... 2-40  
DSP Impulse Pattern................................................................................................................................. 2-42  
DSP Impulse Train Pattern ....................................................................................................................... 2-43  
DSP Index Memory ..................................................................................................................................2-44  
DSP Init Memory......................................................................................................................................2-45  
DSP Integral..............................................................................................................................................2-46  
DSP Inv Chebyshev Coeff ........................................................................................................................2-47  
DSP Inverse FFT ......................................................................................................................................2-48  
DSP Inverse FHT......................................................................................................................................2-49  
DSP Kaiser-Bessel Window ..................................................................................................................... 2-50  
DSP Linear Evaluation ............................................................................................................................. 2-51  
DSP Load ..................................................................................................................................................2-51  
DSP Log....................................................................................................................................................2-52  
DSP Max & Min....................................................................................................................................... 2-53  
DSP Median Filter ....................................................................................................................................2-54  
DSP Multiply ............................................................................................................................................2-55  
DSP Parks-McClellan............................................................................................................................... 2-56  
DSP Polar to Rectangular ......................................................................................................................... 2-59  
DSP Polynomial Evaluation ..................................................................................................................... 2-60  
DSP Power Spectrum................................................................................................................................2-61  
DSP Product..............................................................................................................................................2-61  
DSP Pulse Pattern ..................................................................................................................................... 2-62  
DSP Ramp Pattern ....................................................................................................................................2-63  
DSP Random Pattern ................................................................................................................................2-64  
DSP Rectangular to Polar ......................................................................................................................... 2-65  
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DSP ReFFT............................................................................................................................................... 2-66  
DSP Reset ................................................................................................................................................. 2-66  
DSP Reverse ............................................................................................................................................. 2-67  
DSP Sawtooth Pattern............................................................................................................................... 2-68  
DSP Set..................................................................................................................................................... 2-69  
DSP Shift ..................................................................................................................................................2-69  
DSP Sinc Pattern....................................................................................................................................... 2-70  
DSP Sine Pattern....................................................................................................................................... 2-71  
DSP Square Pattern................................................................................................................................... 2-72  
DSP Square Root ......................................................................................................................................2-73  
DSP Sort ................................................................................................................................................... 2-74  
DSP Start ..................................................................................................................................................2-75  
DSP Subset ............................................................................................................................................... 2-75  
DSP Subtract............................................................................................................................................. 2-76  
DSP Sum................................................................................................................................................... 2-76  
DSP TimeOut............................................................................................................................................2-77  
DSP Triangle Pattern ................................................................................................................................2-78  
DSP Triangular Train................................................................................................................................2-80  
DSP Triangular Window ..........................................................................................................................2-81  
DSP Uniform White Noise ....................................................................................................................... 2-82  
DSP Unwrap Phase................................................................................................................................... 2-83  
DSP Zero Padder ......................................................................................................................................2-84  
Part 4  
NI-DSP Interface Utilities  
Chapter 1  
Introduction to the NI-DSP Interface Utilities ....................................................................1-1  
Overview of the NI-DSP Interface Utilities..............................................................................................1-1  
Installing the NI-DSP Interface Utilities ..................................................................................................1-2  
Using the NI-DSP Interface Utilities ........................................................................................................1-2  
Chapter 2  
Getting Started with the NI-DSP Interface Utilities ....................................................... 2-1  
Creating Your Custom NI-DSP Library ................................................................................................... 2-1  
1. Create Your Source Code of C Functions ............................................................................. 2-1  
GMaxMin.c Example..................................................................................................2-1  
Guidelines for the Custom Functions ..........................................................................2-2  
DSP Board Memory Management............................................................................... 2-3  
2. Compile and/or Assemble Source Code................................................................................2-4  
3. Add Your Object Filenames to a Linker File (ifile) ..............................................................2-4  
4. Add Your New Function Names to a Library Function List File..........................................2-4  
Customizing the DSP Library by Deleting Functions ................................................. 2-5  
5. Run the Build Dispatch Application to Generate an Assembly Dispatch File......................2-6  
6. Compile, Assemble, and Link Your Custom Library............................................................2-7  
Creating Your LabVIEW Interface ..........................................................................................................2-8  
1. Bundle All of the Input Parameters to Arrays....................................................................... 2-8  
2. Call the Custom VI................................................................................................................2-10  
3. Index the Output Arrays to Obtain the Results ..................................................................... 2-10  
Executing the Custom Function from LabVIEW ..................................................................................... 2-12  
Chapter 3  
DSP Board Function Overview ......................................................................................................3-1  
Data Acquisition Functions ......................................................................................................................3-3  
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Contents  
Chapter 4  
Using the DMA VIs..................................................................................................................................4-1  
DSP DMA Copy(DSP to LV)................................................................................................................... 4-3  
DSP DMA Copy(LV to DSP)................................................................................................................... 4-4  
Appendix A  
Error Codes  
..........................................................................................................................................A-1  
Error Conditions........................................................................................................................................A-1  
Appendix B  
Customer Communication  
............................................................................................... B-1  
Glossary........................................................................................................................................... Glossary-1  
..........................................................................................................................................................Index-1  
Index  
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Contents  
Figures  
Part 1  
Figure 1-1.  
Part 2  
Development Paths with the NI-DSP Software ............................................................................. 1-1  
Figure 1-1.  
Figure 1-2.  
Figure 1-3.  
Figure 1-4.  
Figure 1-5.  
Figure 1-6.  
Figure 1-7.  
Figure 1-8.  
Figure 1-9.  
Communication between the PC and the DSP Board ....................................................................1-1  
DSP Handle Cluster ....................................................................................................................... 1-3  
The Hexadecimal Encoding of a Typical DSP Handle..................................................................1-3  
Front Panel–An Example of How to Allocate a DSP Handle Cluster........................................... 1-4  
Block Diagram–An Example of How to Allocate a DSP Handle Cluster..................................... 1-4  
DSP Add VI ................................................................................................................................... 1-5  
The error in/error out Cluster......................................................................................................1-5  
An Example That Does Not Use error in/error out for Sequencing VIs ....................................1-6  
An Example of Using the error in/error out Cluster for Sequential VI Execution..................... 1-7  
Figure 1-10. Front Panel–An Example of Using NI-DSP Analysis VIs ............................................................1-8  
Figure 1-11. Block Diagram–An Example of Using NI-DSP Analysis VIs ......................................................1-8  
Part 3  
Figure 1-1.  
Figure 1-2.  
Choosing DSP2200 from the Functions Menu ..............................................................................1-4  
Spectral Leakage Demonstrated Using Convolution..................................................................... 1-7  
Part 4  
Figure 1-1.  
Figure 1-2.  
NI-DSP for DOS Directory Structure ............................................................................................1-1  
Interface Layers to Onboard Functions..........................................................................................1-2  
Figure 2-1.  
Figure 2-2.  
Figure 2-3.  
Figure 2-4.  
Figure 2-5.  
Figure 2-6.  
Figure 2-7.  
Figure 2-8.  
Figure 2-9.  
Linker File NIDSPLNK................................................................................................................. 2-4  
Library Function List File NIDSP.fnc ........................................................................................... 2-4  
Typical Section of NIDSP.fnc ....................................................................................................... 2-5  
Signals Group Section in dspfncs.h ............................................................................................... 2-6  
Signals Group Section in dispatch.s............................................................................................... 2-6  
How to Bundle Parameters in LabVIEW to Call gmaxmin.c ........................................................2-9  
How to Connect to Custom VI to Call gmaxmin.c ........................................................................2-10  
Block Diagram–How to Index the Output Arrays of the Custom VI ............................................2-11  
Block Diagram–Using the Custom VI to Call gmaxmin.c on theDSP Board from LabVIEW..... 2-11  
Figure 2-10. Front Panel–Using the Custom VI to Call gmaxmin.c on theDSP Board from LabVIEW........... 2-12  
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Contents  
Tables  
Part 1  
Table 1-1.  
Part 3  
Table 1-1.  
Part 4  
Table 2-1.  
Subdirectories Created by SETUP................................................................................................. 1-2  
The NI-DSP Analysis VI Groups ..................................................................................................1-1  
Files Required to Build the Custom DSP Library Example ..........................................................2-7  
Appendix A  
Table A-1.  
NI-DSP Analysis Library Error Codes ..........................................................................................A-1  
NI-DSP SRM for LabVIEW for Windows  
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About This Manual  
The NI-DSP Software Reference Manual for LabVIEW for Windows explains how to use the NI-DSP software  
package for the LabVIEW for Windows environment. The NI-DSP software package contains the NI-DSP Analysis  
VIs, which are high-level digital signal processing (DSP) VIs that call the functions that execute on the  
AT-DSP2200 plug-in board for IBM AT bus and compatible computers. This manual describes how to use the  
NI-DSP Analysis VIs to develop applications in LabVIEW using the AT-DSP2200 board.  
The NI-DSP software package also contains the NI-DSP Interface Utilities. The NI-DSP Interface Utilities are a set  
of tools and examples that help you customize your NI-DSP Analysis VIs and the DSP Library, which is resident on  
the board. This manual contains step-by-step instructions and useful examples to help the LabVIEW developer add  
custom algorithms to the NI-DSP Analysis VIs using the NI-DSP Interface Utilities.  
Assumption of Previous Knowledge  
The material in this manual is for users who are familiar with LabVIEW and the IBM family of computers and  
compatible computers.  
Organization of This Manual  
This manual is divided into four parts.  
•
•
Part 1, Getting Started with NI-DSP, contains a brief product overview, information about the NI-DSP for  
LabVIEW for Windows package, and the procedure for installing the software.  
Part 2, Introduction to the NI-DSP Analysis VIs, describes how to use the NI-DSP Analysis VIs in your  
LabVIEW applications. This part also describes how to manage memory on the DSP board from your  
LabVIEW application, and how to transfer data between your LabVIEW application and the NI-DSP functions  
on the board. This part contains general guidelines for developing NI-DSP applications within LabVIEW.  
•
Part 3, NI-DSP Function Reference, is intended as a reference for users familiar with Part 2. Part 3 is organized  
as follows:  
-
Chapter 1, NI-DSP Analysis VI Reference Overview, contains an overview of the NI-DSP Analysis VIs and  
includes a list of the VIs. This chapter describes how the NI-DSP Analysis VIs are organized, and how to  
access them.  
-
Chapter 2, NI-DSP Analysis VI Reference, contains a brief explanation of each NI-DSP Analysis VI. The  
VIs are arranged alphabetically.  
•
Part 4, NI-DSP Interface Utilities, explains how to customize the NI-DSP Analysis Library on the board and to  
create and run interfaces in LabVIEW to your custom library functions. Part 4 is organized as follows:  
-
Chapter 1, Introduction to the NI-DSP Interface Utilities, contains an overview of the NI-DSP Interface  
Utilities, installation instructions, and explains how to use the NI-DSP Interface Utilities.  
-
Chapter 2, Getting Started with the NI-DSP Interface Utilities, contains a step-by-step example for building  
a custom DSP Library, creating a LabVIEW interface to a custom function, and executing the custom  
function from the LabVIEW environment. The chapter demonstrates this concept with an example of how  
to add a custom function.  
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-
-
Chapter 3, DSP Board Function Overview, contains an overview of the prototypes of the C-callable  
NI-DSP Analysis functions on the DSP board that you can use in your custom programs.  
Chapter 4, Using the DMA VIs, describes two special VIs that transfer data between the host computer and  
the DSP board without interfering with the DSP board.  
•
•
•
•
Appendix A, Error Codes, contains a list of the error codes returned by the NI-DSP Analysis VIs and the  
corresponding error messages.  
Appendix B, Customer Communication, contains forms you can use to request help from National Instruments  
or to comment on our products and manuals.  
The Glossary contains an alphabetical list and description of terms used in this manual, including abbreviations,  
acronyms, metric prefixes, mnemonics, and symbols.  
The Index alphabetically lists topics covered in this manual, including the page where the topic can be found.  
Conventions Used in This Manual  
The following conventions are used in this manual:  
<>  
Angle brackets enclose the name of a key on the keyboard–for example, <enter>.  
bold  
Bold text denotes menus, command names, parameters, function panel items, error  
messages, and warnings.  
DSP board  
DSP board refers to the AT-DSP2200.  
DSP Handle  
DSP Handle refers to a 32-bit long integer code that constitutes an indirect reference to a  
buffer of memory in the memory space of an AT-DSP2200 board. The code contains  
information about the slot number of the board on which that buffer is allocated.  
DSP Handle Cluster  
DSP Library  
DSP Handle Cluster refers to a cluster that constitutes two fields–a DSP Handle and a  
32-bit size that indicates the number of elements the DSP Handle holds.  
DSP Library refers to a common object file format (COFF) that constitutes NI-DSP  
software that resides and runs on the AT-DSP2200 board. The DSP Library consists of  
the Kernel, memory management routines, execution control routines, data  
communication routines, interrupt handling routines, data acquisition routines and a set of  
analysis functions.  
<enter>  
Key names are in lowercase letters.  
Interface Library  
Interface Library refers to the part of the NI-DSP software that resides on the PC and is  
linked with your application in order to communicate data to and from the DSP board.  
The Interface Library communicates with the DSP board using the driver.  
italic  
Italic text denotes emphasis, a cross reference, or an introduction to a key concept.  
italic monospace Italic text in this font denotes that you must supply the appropriate words or values in the  
place of these items.  
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LabVIEW Data Types  
Each VI description includes a data type picture for each control and indicator, as  
illustrated in the following table:  
Control  
Indicator  
Data Type  
Boolean  
String  
Signed 16-bit integer  
Array of signed 16-bit integers  
Signed 32-bit integer  
Array of signed 32-bit integers  
32-bit floating-point number; by default,  
floating-point numbers are double precision  
Array of 32-bit floating-point numbers  
Path  
DSP Handle Cluster  
Array of DSP Handle Clusters  
Error Cluster  
monospace  
Text in this font denotes text or characters that are to be literally input from the keyboard,  
sections of code, programming examples, and syntax examples. This font is also used for  
the proper names of disk drives, paths, directories, programs, subprograms, subroutines,  
device names, array names, structures, variables, filenames, and extensions, and for  
statements and comments taken from program code.  
NI-DAQ  
NI-DSP  
NI-DAQ is used throughout this manual to refer to the NI-DAQ software for  
DOS/Windows/LabWindows unless otherwise noted.  
NI-DSP is used throughout this manual to refer to the NI-DSP software for LabVIEW for  
Windows unless otherwise noted.  
PC  
PC refers to the IBM PC AT and compatible computers, and to EISA personal computers.  
WE DSP32C tools  
WE DSP32C tools is used throughout this manual to refer to the AT&T WE DSP32C  
Developer Toolkit.  
Abbreviations, acronyms, metric prefixes, mnemonics, symbols, and terms are listed in the Glossary.  
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Related Documentation  
The following documentation available from National Instruments contains information that you may find helpful as  
you read this manual.  
•
•
•
•
•
•
•
•
AT-DSP2200 User Manual, part number 320435-01  
LabVIEW Data Acquisition VI Reference Manual, part number 320536-01  
LabVIEW Getting Started Manual for Windows, part number 320533-01  
LabVIEW User Manual, part number 320534-01  
LabVIEW Utility VI Reference Manual, part number 320543-01  
NI-DAQ Function Reference Manual for DOS/Windows/LabWindows, part number 320499-01  
NI-DAQ Software Reference Manual for DOS/Windows/LabWindows, part number 320498-01  
NI-DSP Software Reference Manual for DOS/LabWindows, part number 320436-01  
The following documentation also contains information that you may find helpful as you read this manual:  
•
"A Computer Program for Designing Optimum FIR Linear Phase Digital Filters," McClellan, Parks, and  
Rabiner, IEEE Transactions on Audio and Electroacoustics, Vol. AU-21, No. 6, pp. 506-525, December 1973  
•
•
•
Digital Filter Design, Parks and Burrus, Wiley-Interscience  
Discrete-Time Signal Processing, Oppenheim and Schafer, Prentice Hall  
Numerical Recipes, Cambridge University Press  
Additional Software  
Additional DSP board software includes NI-DAQ for DOS/Windows/LabWindows and the Developer Toolkit.  
NI-DAQ for DOS/Windows/LabWindows  
Your AT-DSP2200 is shipped with the NI-DAQ for DOS/Windows/LabWindows software. NI-DAQ has a library  
of functions that can be called from your application programming environment. These functions include routines  
for analog input (A/D conversion), buffered data acquisition (high-speed A/D conversion), analog output (D/A  
conversion), waveform generation, digital I/O, counter/timer, SCXI, RTSI, and self-calibration. NI-DAQ maintains  
a consistent software interface among its different versions so you can switch between platforms with minimal  
modifications to your code. NI-DAQ comes with language interfaces for Professional BASIC, Turbo Pascal,  
Turbo C, Turbo C++, Borland C++, Microsoft C for DOS; and Visual Basic, Pascal, Microsoft C with SDK, and  
Borland C++ for Windows. NI-DAQ for DOS/Windows/LabWindows software is on high-density 5.25 in. and  
3.5 in. diskettes. You can use the DSP board in conjunction with the National Instruments AT Series data  
acquisition boards and software to create a complete solution for integrated data acquisition and data analysis  
applications.  
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Developer Toolkit  
The Developer Toolkit, an optional software package that you can purchase separately from National Instruments, is  
required for building custom libraries with the NI-DSP Interface Utilities. The Developer Toolkit contains an  
AT&T C compiler, assembler, linker, and documentation. With these tools, you can program AT Series DSP boards  
directly, using theboard flexibility to custom tailor the DSP Library. The C compiler optimizes WE DSP32C code  
and generates assembly language code that can be assembled and linked into a run-time module. When a run-time  
module is completed, use the download tools and the debugger to load, debug, and execute the code, set parameters,  
and report results. The Developer Toolkit also includes the WE DSP32C Support Software Library User Manual  
and the WE DSP32 and WE DSP32C Language Compiler Library Reference Manual.  
Compatible Hardware  
You can use DSP boards in conjunction with the National Instruments AT Series data acquisition boards. In  
particular, the National Instruments AT-DSP2200 is a high-performance, DSP board with high-accuracy audio  
frequency (DC to 51.2 kHz) analog input/output for the PC. The AT-DSP2200 gives the PC a dedicated  
high-speed numerical computation engine that can perform scientific calculations faster than the general-purpose  
80x86 microprocessor on the PC.  
Customer Communication  
National Instruments wants to receive your comments on our products and manuals. We are interested in the  
applications you develop with our products, and we want to help if you have problems with them. To make it easy  
for you to contact us, this manual contains comment and configuration forms for you to complete. These forms are  
in Appendix B, Customer Communication, at the end of this manual.  
© National Instruments Corporation  
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Getting Started with NI-DSP  
This part contains a brief product overview, information about the NI-DSP for LabVIEW for Windows package, and  
the procedure for installing the software.  
Product Overview  
The NI-DSP software package comes with a set of LabVIEW VIs that invoke the digital signal processing (DSP)  
board-resident high-performance functions that efficiently process large blocks of numerical data and perform  
numerically intensive computations. The NI-DSP Analysis VIs include numerical analysis, signal generation, DSP,  
windowing, digital filtering, and memory management that are suitable for simulation, modeling, and sophisticated  
data processing.  
You can use NI-DSP to develop programs in the LabVIEW for Windows environment. This software comes with  
the NI-DSP Interface Utilities so you can customize the DSP Library by adding functions to or deleting functions  
from the Analysis Library on the DSP board and/or add interfaces to these custom functions in LabVIEW.  
Figure 1-1 shows the development path for NI-DSP in the LabVIEW environment.  
NI-DSP for  
LabVIEW  
for Windows  
The LabVIEW  
for Windows  
Development  
Environment  
Interface  
Utilities  
User  
Application  
AT&T  
Development  
Environment  
and Tools  
(Optional)  
Figure 1-1. Development Paths with the NI-DSP Software  
The NI-DSP Software  
The NI-DSP software consists of the NI-DSP for LabVIEW for Windows diskettes.  
The NI-DSP software contains a Warranty Registration Form. Please fill out this form and return it to National  
Instruments. The Warranty Registration Form entitles you to receive product upgrades and technical support.  
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What Your Distribution Diskettes Should Contain  
The NI-DSP software package contains the NI-DSP for LabVIEW for Windows Disks (for licensed LabVIEW for  
Windows users). If your kit is missing any of these components, contact National Instruments.  
Installing NI-DSP for LabVIEW for Windows  
Note: NI-DSP for LabVIEW for Windows is intended for use with the standard LabVIEW for Windows software.  
You must install LabVIEW for Windows before installing NI-DSP. You must install the Data Acquisition  
Library of LabVIEW to run the NI-DSP software.  
Before beginning the software installation, make backup copies of the NI-DSP for LabVIEW for Windows  
distribution disks. Copy each disk onto a correctly labeled backup disk and store the original distribution disks in a  
safe place.  
You can install NI-DSP for LabVIEW for Windows from the DOS prompt, the Windows File Manager, or with the  
Run... command from the File menu of the Program Manager.  
1. Insert Disk 1 into the disk drive and run the SETUP.EXEprogram on Disk 1 using one of the following three  
methods.  
•
•
From the DOS prompt, type X: \SETUP(where X is the proper drive designation).  
From Windows, select Run... from the File menu of the Program Manager. A dialog box appears. Type  
X: \SETUP(where X is the proper drive designation).  
•
From Windows, launch the File Manager. Click on the drive icon that contains Disk 1. Find SETUP.EXE  
in the list of files on that disk and double-click on it.  
2. The installer gives you the option of performing a full installation or a custom installation. Unless you do not  
have sufficient disk space (approximately 4 megabytes), National Instruments recommends that you perform a  
full installation. After you choose an installation, follow the instructions that appear on the screen.  
After calling SETUP, the appropriate directories are created and the needed files are copied to your hard drive.  
SETUPcan also install the NI-DSP Interface Utilities, discussed in Part 4, NI-DSP Interface Utilities, of this manual.  
If you choose Full Installation, SETUPdoes the following things:  
1. SETUPcreates a subdirectory called DSP2200of the vi.libsubdirectory of the LabVIEWdirectory.  
SETUPdecompresses the NI-DSP Analysis VIs (as LabVIEW .LLBfiles) in the DSP2200directory.  
2. SETUPcopies DSP.DLLto your windowsdirectory.  
3. SETUPcreates the subdirectories shown in Table 1-1 under the directory you specified during setup. These  
subdirectories make up the NI-DSP Interface Utilities.  
4. SETUPcreates a subdirectory called DSP2200of the EXAMPLESsubdirectory of the LabVIEWdirectory.  
SETUPcopies all of the NI-DSP VI examples there.  
Table 1-1. Subdirectories Created by SETUP  
Subdirectory Name  
C:\NIDSP\LIB  
C:\NIDSP\DISPATCH  
C:\NIDSP\EXAMPLES  
Description  
Library files for linking with stand-alone programs  
The Dispatch utility and related files  
Contains source code for the examples  
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NIDSPis the name you specify during setup.  
The SETUPprogram prompts you for information including the drive letter and directory in which you have  
installed the standard LabVIEW package. The program also verifies that your hard disk has enough space to hold  
the NI-DSP for LabVIEW for Windows files.  
If you choose Custom Installation, SETUPinstalls only the files you specify.  
Board Configuration  
There are several board configuration parameters that must be established before an NI-DSP application can execute  
properly. These parameters are the board ID number, the board subtype, the base address, the interrupt level, the  
DMA channel, and the pathname of the DSP Library files. These parameters are established differently depending  
on whether you are installing the AT-DSP2200 in an ISA (or AT) bus computer or an EISA bus computer.  
Installation on an ISA (or AT) Bus Computer  
A configuration utility is supplied with the LabVIEW data acquisition software for establishing all the configuration  
parameters on ISA bus computers. This utility, called WDAQCONF.EXE, saves the configuration parameters in a file  
named WDAQCONF.CFG. Use the WDAQCONFutility to assign a board ID number to your AT-DSP2200, to choose  
the memory subtype (either 64 Kwords or ≥128 Kwords), to set the base address, interrupt level, and DMA channel,  
and to specify the pathname of the DSP Library file.  
Two DSP Library files are supplied with your NI-DSP software–LV2200S.OUTand LV2200.OUT.  
LV2200S.OUTis intended for use with the 64 Kword version of the AT-DSP2200. LV2200.OUTis intended for  
use with any other version of the board. With the WDAQCONFutility, you can enter a complete path that will include  
the DSP Library file name. If you enter complete pathnames, you can configure the NI-DSP software to  
automatically load custom versions of the DSP Library files.  
If you installed the Data Acquisition Library of LabVIEW, you can find WDAQCONF.EXEof your LabVIEW  
directory. From Windows, you run WDAQCONF.EXEby double-clicking on its icon.  
Installation on an EISA Bus Computer  
Installing the AT-DSP2200 board on an EISA bus computer involves two different configuration utilities.  
•
A system configuration utility is supplied with your computer by your computer vendor. This utility, along with  
the !NIC1100.CFGEISA configuration file installed by the LabVIEW SETUPprogram, is used to assign a  
slot number to the AT-DSP2200, to choose the memory subtype (either 64 Kwords or ≥128 Kwords), and to set  
the base address, interrupt level, and DMA channel.  
There are typically two methods for running your EISA system configuration utility.  
1. Boot from the diskette containing the utility and place a copy of the !NIC1100.CFGfile on this diskette.  
2. Run the utility from a directory on your hard disk and place a copy of the !NIC1100.CFGfile in this  
directory. The EISA system configuration utility is typically named CF.EXE.  
•
You must use the WDAQCONFutility to enter the DSP Library file pathname. You can only do this after  
completing the EISA system configuration. Refer to the information concerning the establishment of this  
pathname in the previous section titled, Installation on an ISA (or AT) Bus Computer.  
Before using NI-DSP, you must run WDAQCONF.EXEto configure your DSP board.  
For more information about board configuration, refer to Chapter 1, Introduction and Configuration, of the  
LabVIEW Data Acquisition VI Reference Manual.  
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Introduction to the NI-DSP Analysis VIs  
This part describes how to use the NI-DSP Analysis VIs in your LabVIEW applications. This part also describes  
how to manage memory on the DSP board from your LabVIEW application, and how to transfer data between your  
LabVIEW application and the NI-DSP functions on the board. This part contains general guidelines for developing  
NI-DSP applications within LabVIEW.  
Using the NI-DSP VIs in LabVIEW  
LabVIEW users use the NI-DSP Analysis VIs as if they were any other standard VIs, as described in the LabVIEW  
User Manual. Notice, however, that the NI-DSP Analysis VIs run analysis code on the DSP board rather than on the  
host CPU. One of the major features includes the memory management and data transfer VIs, which are discussed  
in detail in the section titled Memory Management and Data Transfer later in this chapter.  
AT-DSP2200 Software Overview  
The AT-DSP2200 board, working in conjunction with your personal computer, is a powerful numeric processor for  
high-speed analysis of data arrays. The NI-DSP for LabVIEW for Windows software includes a number of utilities  
and low-level memory management and data transfer VIs that facilitate communication between the DSP board and  
the host computer. Figure 1-1 is a block diagram of the software utilities and libraries that control the  
AT-DSP2200. The DSP Library and the low-level memory management and data transfer functions reside and  
execute on the board. You can customize the DSP Library to optimize performance, as described in Part 4,  
Chapter 2, Getting Started with the NI-DSP Interface Utilities, of this manual. Your application programs and the  
Interface Library, however, reside on the host PC.  
PC  
AT-DSP2200  
AT or EISABus  
DSP Hardware  
DSP Software  
User  
Application  
in LabVIEW  
Onboard Kernel,  
DSP Board  
Memory  
CPU  
Management,  
Data Transfer  
Functions  
VI  
Interface  
(CIN)  
Onboard Memory  
DSP Library  
Interface  
Library  
(DSP.DLL)  
Figure 1-1. Communication between the PC and the DSP Board  
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The AT-DSP2200 can process large amounts of data, separately and distinctly from the host PC processor. The  
board consists not only of a signal processing chip, but also memory where data that the board processes must  
reside. The AT-DSP2200 does not have access to memory locations on the host PC. Therefore, you must download  
all data from your application programs to DSP board memory before processing it.  
The Interface Library, DSP.DLL, and the Code Interface Node (CIN) interface, which reside on the PC, serve as a  
bridge between your application programs in LabVIEW and the DSP software running on the board. When you call  
an NI-DSP Analysis VI, the VI passes the parameters to the CIN first, which then passes the parameters to the  
Interface Library, DSP.DLL. The Interface Library determines what type of parameters are being passed, decides  
how to set up the data in DSP board memory, and then calls the actual functions that will run on the board.  
When a function on the DSP board processes data, it assumes the data is resident in DSP board memory. Because  
transferring data between the PC and the DSP board slows down processing, none of the NI-DSP Analysis VIs  
transfer data back and forth internally except the data transferring VIs. The NI-DSP Analysis VIs process the data  
buffers that are already on the board and leave the results on the board.  
If the data buffer you want to process using the DSP board is in PC memory, you must copy the data to the DSP  
board before you call a function on the DSP board to process the data. To see the results, you must then copy the  
data back to the PC. Several special NI-DSP Analysis VIs perform these transfers. For scalars, the NI-DSP  
Analysis VIs automatically perform the transfer for you.  
The representation of data buffers in the NI-DSP Analysis VIs is not the normal LabVIEW data array representation  
because the data buffers indicate the data location on the DSP board instead of the PC address. A special structure,  
called a DSP Handle Cluster, represents the data buffer on the DSP board from LabVIEW. The DSP Handle Cluster  
is a coded DSP board memory address that indicates where the data buffer is on the DSP board. You must call the  
DSP Allocate Memory VI to obtain a valid DSP Handle Cluster. Several VIs can manage the memory on the DSP  
board. You can allocate and deallocate memory on the DSP board using these VIs. The next section, Memory  
Management and Data Transfer, discusses the VIs used to allocate memory and transfer data buffers to and from the  
DSP board.  
Memory Management and Data Transfer  
This section describes how to manage memory on the DSP board from your LabVIEW application and how to  
transfer data between your LabVIEW application and the DSP board.  
The NI-DSP for LabVIEW package contains a set of VIs that manage memory space on the DSP board and help  
improve data transfers between the DSP board and your application. There are VIs for allocating memory buffers on  
the DSP board, for indexing into previously allocated buffers, for deallocating buffers and for copying data between  
DSP and LabVIEW. The following VIs, described in greater detail in Part 3 of Chapter 2, NI-DSP Analysis VI  
Reference, handle memory management on the DSP board and data transfers between the DSP board and your  
LabVIEW application:  
•
•
•
•
•
•
•
Copy Mem[DSP to DSP]  
Copy Mem[DSP to LV]  
Copy Mem[LV to DSP]  
DSP Allocate Memory  
DSP Free Memory  
DSP Index Memory  
DSP Init Memory  
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The DSP Allocate Memory VI allocates memory buffers on the DSP board and returns a DSP Handle Cluster, which  
has two fields that uniquely describe this buffer–a DSP Handle and a size.  
Figure 1-2. DSP Handle Cluster  
DSP Handle is a 32-bit integer containing information that indicates the board on which the allocated buffer resides,  
and an index into an onboard Memory Look Up Table (MLUT) that holds the actual DSP address of the buffer that  
this handle represents. Figure 1-3 shows how a DSP Handle is encoded. The size field holds the number of  
elements in this buffer. An element can be 4 bytes (for 32-bit floating-point data or long integer data) or 2 bytes (for  
16-bit integer data) depending on the bytes per element selector used in the DSP Allocate Memory VI.  
X
X
X
X
3
0
0
4
Index into the  
MLUT of the  
Owner DSP Board  
Board Number of  
Owner DSP Board  
Special Code  
Figure 1-3. The Hexadecimal Encoding of a Typical DSP Handle  
The first four hexadecimal numbers (upper 16 bits) of the DSP Handle, shown in Figure 1-3, are a special value.  
The interface code for a particular function that your application calls decodes these four hexadecimal numbers to  
determine if the argument is a valid DSP Handle.  
Notes: Do not change the value of a DSP Handle Cluster. Keep in mind that a DSP Handle Cluster is just an entry  
of a table that indicates where the data buffer is on the DSP board. If you want to operate on part of the  
data in that buffer, use the DSP Index Memory VI or the DSP Subset VI to obtain a new DSP Handle  
Cluster to hold the part of the data. Then operate on the new DSP Handle Cluster.  
The Memory Look-Up Table (MLUT) has only 128 entries. You can allocate only a total of 128 different  
DSP Handle Clusters. Although you might have physical memory on the DSP board, you will get an error  
message for not having enough memory if you already have 128 DSP Handle Clusters in use. Free the DSP  
Handle Clusters that are not in use. The DSP Init Memory VI will free all DSP Handle Clusters on the  
specified DSP board.  
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Figures 1-4 and 1-5 show how to allocate a DSP Handle Cluster of 2,048 4-byte-long elements on board 3. The  
board number on which the buffer is allocated is important for determining the ownership of the buffer. When  
making a VI call, the same DSP board on which the function is to execute must own all of the DSP Handle Clusters  
or an error code is returned. Only the DSP Allocate Memory VI and few other VIs that do not have DSP Handle  
Clusters as input parameters have a board slot parameter. VIs that have DSP Handle Clusters as input parameters  
obtain the board slot information from their own DSP Handle Clusters. All of the DSP Handle Clusters should have  
the same slot information, because the DSP VIs assume that all are executing on the same DSP board.  
Figure 1-4. Front Panel–An Example of How to Allocate a DSP Handle Cluster  
Figure 1-5. Block Diagram–An Example of How to Allocate a DSP Handle Cluster  
For all of the NI-DSP Analysis VIs, the array data type is DSP Handle Cluster. Before you call any of these VIs,  
call the DSP Allocate Memory VI to obtain a valid DSP Handle Cluster, which you then use as a reference to your  
data buffer. The Analysis VIs assume that the data is already on the board and stores the results on the board. If you  
want to copy data between the PC and the DSP board, use either the Copy Mem(LV to DSP) VI or the Copy  
Mem(DSP to LV) VI to copy data back and forth.  
If you use the DSP Allocate Memory VI in your program, use the DSP Free Memory VI to free buffers allocated  
when you do not need them any more. The board holds these allocations in memory even after your application has  
completed or you exit LabVIEW unless you execute the DSP Init Memory VI or reload the DSP Library. Thus, it is  
important to free all buffers your application allocated before you exit the application or you may run out of memory  
on the board.  
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Special Features of the NI-DSP Analysis VIs  
This section describes the special features of the NI-DSP Analysis VIs that make them different from other  
LabVIEW VIs.  
•
DSP Handle Cluster in/out. The way you specify the output data buffers for NI-DSP Analysis VIs is different  
from the way you would specify output data buffers for other LabVIEW VIs. DSP Handle Clusters also  
represent all the output data buffers in the NI-DSP Analysis VIs. To use valid DSP Handle Clusters for the  
NI-DSP VI output data buffers, you must use the DSP Allocate Memory VI to obtain the DSP Handle Clusters  
before you use them. Supply all of the output DSP Handle Clusters as inputs to tell the DSP board where the  
output buffers are. Every output DSP Handle Cluster is identical to the corresponding input DSP Handle  
Cluster. The two DSP Handle Clusters are internally connected. The output is an indicator. The input is a  
control. For example, in the DSP Add VI, shown in Figure 1-6, Z is the DSP Handle Cluster that indicates  
where to store the results. You use Z in to connect to a valid DSP Handle Cluster that you previously allocated.  
Z in tells the DSP board where the results will be stored. Z out is the location where the results have already  
been stored. Because Z in and Z out are the same DSP Handle Cluster, you need to free only one of them when  
you want to deallocate their DSP board buffer.  
Figure 1-6. DSP Add VI  
All of the controls and indicators in the NI-DSP Analysis VIs follow the Z in, Z out naming convention and  
work in the same way as previously described in the example, except for the error in/error out cluster.  
•
Error Handling. All of the NI-DSP Analysis VIs have an error input and an error output for managing and  
reporting errors. The error in/error out cluster used by the NI-DSP VIs and many other high-level I/O  
operations is a cluster containing a Boolean indicating whether the data should be treated as an error, a 32-bit  
error code, and a descriptive string that usually contains the name of the source of the error. The error in/error  
out cluster is shown in Figure 1-7.  
Figure 1-7. The error in/error out Cluster  
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The error in/error out cluster contains the following elements:  
The boolean value is true if an error occurred, false if no error occurred.  
code is the error code.  
source is the source of the error. If an error occurs during execution, the VI sets source to the name  
of the VI that produced the error.  
Every VI checks error in first. If there is an error, the VI does not execute any DSP code but simply passes the  
contents of error in to the error out cluster. If there is no error, the VI executes. One advantage of this error  
in/error out design is that you can connect several I/O operations together so that, if an error occurs, subsequent VIs  
do not perform undesired actions. DSP Free Memory will execute even if an error occurs. This ensures that  
allocated buffers are freed even if an error occurred.  
Another advantage of this error in/error out design is that you can establish the order of a set of operations, even if  
there is no other data flow between the operations. Connecting the error out of the first VI to the error in of the  
second VI establishes data flow and therefore execution order. You could do the same thing with a Sequence  
structure, but with the error in/error out design, you can establish the order with all of the operations at the top level  
of the block diagram. For example, in Figure 1-8, you allocate DSP Handle Clusters X and Y as inputs, and you want  
to free X and Y after the DSP Add VI has been executed. If you simply connect X to the DSP Free Memory VI as  
shown in Figure 1-8, there is no sequential order between the DSP Add VI and the DSP Free Memory VI. If the DSP  
Free Memory VI executes first, the DSP Add VI will receive an invalid handle because that DSP Handle Cluster was  
deallocated.  
Figure 1-8. An Example That Does Not Use error in/error out  
for Sequencing VIs  
If you connect the VIs as shown Figure 1-9 instead, you ensure that the DSP Add VI executes before the DSP Free  
Memory VI.  
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error out of the Copy Mem(LV to DSP) VI is  
connected to the error in of the DSP Free  
Memory VI  
error out of the DSP Add VI is  
connected to the error in of the  
Copy Mem(LV to DSP) VI  
Figure 1-9. An Example of Using the error in/error out Cluster for Sequential VI Execution  
For more information about the error in/error out cluster, refer to Chapter 2, Error Handler VIs, in the LabVIEW  
Utility VI Reference Manual.  
Hints for Improving the Execution Speed on the DSP Board  
Check each of the following things to maximize your DSP board performance:  
•
Allocate as many of the DSP Handle Clusters as you can before you operate on the data. Keep all data on the  
DSP board until you finish all of the processing. Reduce the number of data transfers between the DSP board  
and the PC as much as possible. The functions that run on the DSP board are very fast, but transferring data  
between the DSP board and the PC and memory allocation slows the total processing performance.  
•
Use the error in/error out cluster for sequencing VI execution. Be sure all of your VIs run in the correct  
sequence. Use the error in/error out cluster to propagate the errors. If an error occurs, you can tell where the  
error happens. You can use the LabVIEW error handler VIs in the Utility option of the Functions menu to  
obtain pop-up error messages. Refer to the LabVIEW Utility VI Reference Manual for more information about  
these VIs.  
•
•
Many analysis routines on the DSP board can be performed in place; that is, the input and output array can be  
the same array. This is very important to remember when you are processing large amounts of data. Large  
32-bit floating-point arrays consume a lot of memory. If the results you want do not require that you keep the  
original array or an intermediate array of data, perform analysis operations in place whenever possible. For  
example, use the same DSP Handle Cluster for the input and output data buffers in your diagram in LabVIEW.  
This will save your DSP board memory.  
Several intermediate-level data acquisition VIs work with DSP Handle Clusters. These VIs can acquire data  
and leave it on the board. You can use the NI-DSP Analysis VIs to operate on this data and then copy the  
processed results back to the PC. In this way, you dramatically reduce the data transfer overhead between the  
PC and the DSP board, and improve the overall performance. For more information about these data  
acquisition VIs, refer to the LabVIEW Data Acquisition VI Reference Manual. An example that shows you how  
to use a DSP Handle Cluster to acquire data and process this data on the DSP board can be found in the  
DSP2200subdirectory of the EXAMPLESsubdirectory of your LabVIEWdirectory.  
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An Example of Using NI-DSP Analysis VIs  
Figures 1-10 and 1-11 show the front panel and block diagram, respectively, of an example using NI-DSP Analysis  
VIs.  
Figure 1-10. Front Panel–An Example of Using NI-DSP Analysis VIs  
Figure 1-11. Block Diagram–An Example of Using NI-DSP Analysis VIs  
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This example shows you how to obtain the power spectrum of a sine wave signal. First, generate a sine wave that  
you want to analyze using the LabVIEW Analysis VIs, then use the Copy Mem(LV to DSP) VI to copy the data of  
this sine signal to the DSP board. Before you copy the data, you must call the DSP Allocate Memory VI to allocate  
a DSP Handle Cluster that reserves a data buffer on the DSP board. Connect this DSP Handle Cluster to the  
destination in terminal of the Copy Mem(LV to DSP) VI to indicate where the data will be stored on the DSP  
board. After the data is copied to the DSP board, call the DSP Power Spectrum VI to perform a power spectrum on  
the data. After you finish the analysis, the results are stored in the data buffer indicated by the DSP Handle Cluster  
you previously allocated. If you want to see the results, call the Copy Mem(DSP to LV) VI to copy data back to  
LabVIEW. Figure 1-10 shows the power spectrum of a sine wave. The last step is to call the DSP Free Memory VI  
to free the DSP Handle Cluster that you allocated. This example connects all of the error out clusters of the  
previous VIs to the error in clusters of the subsequent VIs to establish the proper sequence and to pass through an  
error, should it occur, without executing the rest of the VIs.  
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NI-DSP Analysis VI Reference Overview  
This chapter contains an overview of the NI-DSP Analysis VIs and includes a list of the VIs. This chapter describes  
how the NI-DSP Analysis VIs are organized and how to access them.  
The NI-DSP Analysis VI Overview  
The NI-DSP Analysis VIs are a set of high-performance VIs that efficiently process large blocks of numerical data  
and perform numerically intensive computations. The NI-DSP Analysis VIs include numerical analysis, signal  
generation, digital signal processing, digital filtering, and windowing operations that are suitable for simulation,  
modeling, and sophisticated data processing.  
The NI-DSP Analysis VIs are presented in alphabetical order in Chapter 2, NI-DSP Analysis VI Reference.  
Table 1-1 lists these VIs by group.  
Table 1-1. The NI-DSP Analysis VI Groups  
Signal Generation  
DSP Sine Pattern  
DSP Pulse Pattern  
DSP Impulse Pattern  
DSP Impulse Train Pattern  
DSP Ramp Pattern  
DSP Sinc Pattern  
DSP Square Pattern  
DSP Triangle Pattern  
DSP Triangular Train  
DSP Sawtooth Pattern  
DSP Uniform White Noise  
DSP Random Pattern  
DSP Gaussian White Noise  
Frequency Domain  
DSP ReFFT  
DSP Complex FFT  
DSP Inverse FFT  
DSP Power Spectrum  
DSP Cross Power  
DSP FHT  
DSP Inverse FHT  
DSP Zero Padder  
Time Domain  
DSP Convolution  
DSP Deconvolution  
DSP Correlation  
DSP Decimate  
DSP Derivative  
DSP Integral  
(continues)  
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Table 1-1. The NI-DSP Analysis VI Groups (Continued)  
Filters  
DSP Butterworth Coefficients  
DSP Chebyshev Coefficients  
DSP Inverse Chebyshev Coeff  
DSP Elliptic Coefficients  
DSP IIR Filter  
DSP Equi-Ripple LowPass  
DSP Equi-Ripple HighPass  
DSP Equi-Ripple BandPass  
DSP Equi-Ripple BandStop  
DSP Parks-McClellan  
DSP Median Filter  
Windows  
DSP Blackman Window  
DSP Exact Blackman Window  
DSP Blackman Harris Window  
DSP Hanning Window  
DSP Hamming Window  
DSP Flat Top Window  
DSP General Cosine Window  
DSP Exponential Window  
DSP Force Window  
DSP Kaiser-Bessel Window  
DSP Triangular Window  
Array Functions  
DSP Add  
DSP Subtract  
DSP Multiply  
DSP Divide  
DSP Absolute  
DSP Square Root  
DSP Product  
DSP Sum  
DSP Log  
DSP Clip  
DSP Reverse  
DSP Shift  
DSP Sort  
DSP Linear Evaluation  
DSP Max & Min  
DSP Polynomial Evaluation  
DSP Subset  
DSP Set  
DSP Unwrap  
DSP Polar to Rectangular  
DSP Rectangular to Polar  
Memory Management  
DSP Allocate Memory  
Copy Mem(LV to DSP)  
Copy Mem(DSP to LV)  
Copy Mem(DSP to DSP)  
DSP Free Memory  
DSP Index Memory  
DSP Init Memory  
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Table 1-1. The NI-DSP Analysis VI Groups (Continued)  
Utility Functions  
DSP Reset  
DSP Load  
DSP Start  
DSP Timeout  
DSP Custom  
DSP DMA Copy(DSP to LV)  
DSP DMA Copy(LV to DSP)  
DSP Handle to Address  
Analysis VI Organization  
After installation, the NI-DSP Analysis VIs reside in the following VI library files (LabVIEW .LLBfiles) within  
the DSP2200 option:  
•
•
Signal Generation contains VIs that generate digital patterns.  
Frequency Domain contains VIs that perform frequency domain transformations, frequency domain analysis,  
and other transforms such as the Hartley transform.  
•
•
•
•
•
Time Domain contains VIs that perform direct time series analysis of signals.  
Filters contains VIs that perform IIR and FIR filtering functions.  
Windows contains VIs that perform smoothing windowing.  
Array contains VIs that perform arithmetic operations on arrays.  
Memory Management contains VIs to perform allocating, indexing, copying, and freeing memory on the  
AT-DSP2200 board.  
•
Utility contains VIs for controlling the operation of the AT-DSP2200 board.  
After installation, the eight analysis VI libraries appear in the Functions menu in the order shown in the preceding  
list under the DSP2200 option. You can reorganize the folders and the VIs to suit your needs and applications.  
Accessing the NI-DSP Analysis VIs  
To access the analysis VIs from the block diagram window, choose DSP2200 from the Functions menu as shown in  
Figure 1-1, proceed through the hierarchical menus, and select the VI you want. The icon corresponding to that VI  
appears in the block diagram and is ready to be wired.  
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Figure 1-1. Choosing DSP2200 from the Functions Menu  
About the Fast Fourier Transform (FFT)  
The VIs in the Frequency Domain group are based upon the discrete implementation and optimization of the Fourier  
Transform integral. The Discrete Fourier Transform (DFT) of a complex sequence X containing n elements is  
obtained using the following formula:  
n-1  
Y[i] = ∑ X[k] * exp (-j2π ik / n), for i = 0, 1, …, n-1  
k=0  
where Y[i] is the ith element of the DFT of X and j = √-1.  
The DFT of X also results in a complex sequence Y of n elements. Similarly, the Inverse Discrete Fourier  
Transform (IDFT) of a complex sequence Y containing n elements is obtained using the following formula:  
n-1  
X[i] = (1/n) ∑ Y[k] * exp (j2π ik / n), for i = 0, 1, …, n-1  
k=0  
where X[i] is the ith element of the IDFT of Y and j = √-1.  
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The discrete implementation of the DFT is a numerically intense process. However, it is possible to implement a  
fast algorithm when the size of the sequence is a power of two. These algorithms are known as FFTs, and can be  
found in many introductory digital signal processing (DSP) texts.  
The resulting complex FFT sequence has the conventional DSP format as described in this section.  
If there are n number of elements in the complex sequence and k = n/2, then the output of the FFT is organized as  
follows:  
Y[0]  
Y[1]  
Y[2]  
:
Y[k-1]  
Y[k]  
Y[k+1]  
:
DC component  
Positive first harmonic  
Positive second harmonic  
:
Positive k-1 harmonic  
Nyquist frequency  
Negative k-1 harmonic  
:
Y[n-2]  
Y[n-1]  
Negative second harmonic  
Negative first harmonic  
The following conventions and restrictions apply to the VIs in the Frequency Domain folder:  
m
•
•
All arrays must be a power of two: n = 2 , m = 1, 2, 3, …, 24 (limited by onboard memory).  
Complex sequences are manipulated using two arrays. One array represents the real elements. The other array  
represents the imaginary elements.  
The following notation is used to describe the FFT operations performed in the Frequency Domain class:  
•
•
Y = FFT {X}, the sequence Y is the FFT of the sequence X.  
-1  
Y = FFT {X}, the sequence Y is the inverse FFT of the sequence X.  
X is usually a complex array but can be treated as a real array.  
About Filtering  
All of the VIs in the Filters group are digital filters that can be represented by the computational algorithm that best  
describes the relationship between the input and output discrete time sequences. This computational algorithm is  
referred to as the Linear Constant Coefficient Difference Equation. This equation relates the input and output by the  
basic operations of addition, delay and multiplication. The following equation relates the input and output  
sequences x and y, respectively at the discrete time instant n:  
i = N-1  
i = M-1  
a(0)*y(n) = ∑ (x[n-i]*b(i)) - ∑ (y[n-i]*a(i))  
(a)  
i = 0  
i = 1  
where :  
x
y
a
is the discrete time input signal to the system represented by the filter  
is the discrete time output signal of the system represented by the filter  
is the set of coefficients applied to the input in the linear difference equation and represent the  
multiplication factors for delays. The equation suggests that there are N such coefficients.  
is the set of coefficients applied to the output in the linear difference equation and represent the  
multiplication factors for delays. The equation suggests that there are M such coefficients.  
b
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The set of coefficients a and b are often referred to as the numerator and denominator coefficients, respectively.  
Another common way to refer to them is as the feedforward and feedback coefficients. This is due to the  
mathematical derivation that led to equation a. Refer to Discrete-Time Signal Processing by Oppenheim and  
Schafer for more information. Another frequent assumption is that a(0)=1.0. For example, let us assume M = 4,  
N = 4 and n = 2. Using the filtering equation produces:  
a(0)*y(2) = b(0)*x(2) + b(1)*x(1) + b(2)* x(0) + b(3)* x(-1) - a(1)*y(1) - a(2)*y(0) - a(3)*y(-1)  
(b)  
The filtering equation suggests that in order to compute the value of the output at n = 2, you not only need the  
coefficients that represent the filter that is producing this output sequence, but also the value of the current input and  
output, the values of the input and output one time unit ago, the values of the input and output two time units ago,  
and the values of the input and output three time units ago. You need some “history” about the previous outputs of  
the filter as well as the previous inputs to the filter. The amount of history (number of previous output and input  
samples) depends on the lengths of the arrays a and b (filter coefficients arrays).  
At time n = 0, it is important to note that the filtering equation becomes:  
a(0)*y(0) = b(0)*x(0) + b(1)*x(-1) + b(2)* x(-2) + b(3)* x(-3) - a(1)*y(-1) - a(2)*y(-2) - a(3)*y(-3)  
(c)  
Thus, for the function filter to properly operate as of time n = 0, you need to supply some history about previous  
behavior. The filter function then updates the history as time goes on, keeping track of previous input values and  
corresponding outputs. This history, at time n = 0, is referred to as the initial conditions on the input and output of  
the filter.  
Digital filters fall into two classes–Infinite Impulse Response filters (IIR filters) and Finite Impulse Response filters  
(FIR filters). Notice that IIR filters are represented by equation (a) while the FIR filters can be represented by the  
same equation provided all a's are zero except for a(0) as shown in the following equation:  
i = N  
a(0)*y(n) = ∑ (x[n-i]*b(i))  
(d)  
i = 0  
The NI-DSP Analysis VIs have a set of VIs that implement IIR and FIR filters. Because all digital filters are  
approximations of their analog design counterparts, there are several techniques for designing a digital filter.  
For the IIR filter design, the NI-DSP Analysis VIs have four approaches representing four different techniques of  
obtaining digital filter specifications (coefficients to equation (a))–Butterworth, Chebyshev, inverse Chebyshev, and  
elliptic techniques. With each design technique, you can obtain the coefficients for lowpass, highpass, bandpass,  
and bandstop filters from the respective NI-DSP Analysis VIs.  
For the FIR filters, the NI-DSP Analysis VIs allow the design of a multiband FIR linear phase filter using the Parks-  
McClellan algorithm. The frequency response in each band has equal ripples that can be adjusted by a weighting  
factor. For more information, please refer to Digital Filter Design by Parks and Burrus, or "A Computer Program  
for Designing Optimum FIR Linear Phase Digital Filters," by McClellan, Parks, and Rabiner.  
The IIR VIs generate filter coefficients that represent the a's and b's in the equations a and b. No filtering is actually  
performed. The IIR filter design coefficients all have a(0) = 1.0. You can use the general-purpose VI that accepts  
filter coefficients, initial conditions on the input and output sequences, and an input sequence to filter any of the  
filter specifications. This VI filters the input sequence and provides the final conditions on the output and input of  
the filter.  
About Windowing  
Almost every application requires you to use finite length signals. This requires that continuous signals be  
truncated, using a process called windowing.  
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The simplest window is a rectangular window. Because this window requires no special effort it is commonly  
referred to as the no window option. Remember, however, that a discrete signal and its spectrum is always affected  
by a window. Let x[n] be a digitized time-domain waveform that has a finite length of n. w[n] is a window  
sequence of n points. The windowed output is calculated as follows:  
y[i] = x[i] * w[i]  
(1)  
If X, Y, and W are the spectra of x, y, and w, respectively, the time-domain multiplication in formula 1 is equivalent  
to the convolution shown as follows:  
Y[k] = X[k] Θ W[k].  
(2)  
Convolving with the window spectrum always distorts the original signal spectrum in some way. A window  
spectrum consists of a big mainlobe and several sidelobes.  
The mainlobe is the primary cause of lost frequency resolution. When two signal spectrum lines are too close to  
each other, they may fall in the width of the mainlobe, causing the output of the windowed signal spectrum to have  
only one spectrum line. Use a window with a narrower mainlobe to reduce the loss of frequency resolution. It has  
been shown that a rectangular window has the narrowest mainlobe, so that it provides the best frequency resolution.  
The sidelobes of a window function affect frequency leakage. A signal spectrum line will leak into the adjacent  
spectrum if the sidelobes are large. Once again, the leakage results from the convolution process. Select a window  
with relatively smaller sidelobes to reduce spectral leakage. Unfortunately, a narrower mainlobe and smaller  
sidelobes are mutually exclusive. For this reason, selecting a window function is application dependent. An  
example of a windowed spectrum in the continuous case is shown in Figure 1-2.  
*
Signal Spectrum  
Window Spectrum  
Windowed Signal Spectrum  
Figure 1-2. Spectral Leakage Demonstrated Using Convolution  
The original signal spectrum is convolved with the window spectrum and the output is a smeared version of the  
original signal spectrum. In this example, you can still see four distinctive peaks from the original signal, but each  
peak is smeared and the frequency leakage effect is clear.  
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Window definitions used in National Instruments analysis libraries are designed in such a way that the window  
operations in the time domain are exactly equivalent to the operations of the same window in the frequency domain.  
To meet this requirement, the windows are not symmetrical in the time domain, that is:  
w[0] ≠ w[N-1]  
(3)  
where N is the window length. They are usually symmetrical in the frequency domain, however. For example, the  
Hamming window definition uses the formula:  
w[i] = 0.54 - 0.46 cos(2πi/N)  
(4)  
Other manufacturers may use a slightly different definition, such as:  
w[i] = 0.54 - 0.46 cos(2πi/N-1)  
(5)  
The difference is small if N is large.  
Formula 4 is not symmetrical in the time domain, but it ensures that the time domain windowing is equivalent to the  
frequency domain windowing. If you want to have a perfectly symmetrical sequence in the time domain, you must  
write your own windowing function using formula 5.  
The choice of a window depends on the application. For most applications, the Hamming or Hanning windows  
deliver good performance.  
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This chapter contains a brief explanation of each NI-DSP Analysis VI . The VIs are arranged alphabetically.  
Copy Mem(DSP to DSP)  
Copies a buffer of data from the Source  
buffer on the DSP board that is referred to  
by a DSP Handle Cluster to the destination  
buffer on the DSP board, which is referred  
to by another DSP Handle Cluster. Source  
and destination buffers should be on the  
same DSP board.  
To copy data correctly from one DSP  
buffer to another DSP buffer, you must set the data type to the appropriate type to indicate what kind of data is on  
the DSP board. The VI has three data types–32-bit floating-point data, 16-bit short integer data, and 32-bit long  
integer data.  
Source is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the  
data that you want to copy to the destination.  
data type indicates the type of data that Source contains. The VI has three data types:  
0: 32-bit floating-point data.  
1: 16-bit short integer data.  
2: 32-bit long integer data.  
data type defaults to 32-bit floating-point data.  
Destination in is a DSP Handle Cluster that indicates the destination memory buffer on the DSP board  
that will contain the data copied from source buffer.  
Destination out is a DSP Handle Cluster that is identical to the Destination in, but with the source  
buffer data already copied to the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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Copy Mem(DSP to LV)  
Copies an entire or partial buffer  
of data according to the  
entire/partial copy selector from  
the Source buffer on the DSP  
board that is referred to by a DSP  
Handle Cluster to the destination  
buffer in LabVIEW.  
To copy data correctly from the  
DSP board to LabVIEW, you  
must indicate what type of data is  
stored in the Source buffer on the DSP board. You must set the destination type to the appropriate type and wire to  
the corresponding destination terminal. The VI has three destination types–float (32-bit), short (16-bit), and long  
(32-bit). To copy different types of data, you must wire to the appropriate destination terminal that corresponds to  
the destination type you choose. Remember, you must wire only one kind of destination terminal.  
If you set the entire/partial copy selector to entire copy, all the data in the Source buffer will be copied back to the  
destination without considering the values of offset and size. Otherwise, only the number of size the data in the  
Source buffer, starting from the offset, will be copied back to the destination.  
entire/partial copy selector has two types: entire copy and partial copy. It defaults to entire copy.  
0: entire copy.  
1: partial copy.  
Source is a DSP Handle Cluster that indicates the memory buffer on the DSP board which contains the  
data that you want copy to the destination in LabVIEW.  
destination type indicates the type of the destination data on the DSP board. It has three options:  
0: 32-bit floating-point.  
1: 16-bit short integer.  
2: 32-bit long integer.  
destination type defaults to 32-bit floating point.  
offset indicates where to start to copy data from the Source buffer on the DSP board to the destination  
buffer in the LabVIEW. offset defaults to 0. This parameter is ignored when entire/partial copy  
selector is set to entire copy.  
size indicates how much data to copy from the Source buffer on the DSP board to the destination buffer  
in LabVIEW. size defaults to 0. If offset plus size is greater than the number of elements in the Source  
buffer, the VI returns an error. This parameter is ignored when entire/partial copy selector is set to  
entire copy.  
destination(float) is the terminal to which you should wire the destination buffer if the data you want to  
copy is 32-bit floating-point data array.  
destination(long) is the terminal to which you should wire the destination buffer if the data you want to  
copy is 32-bit long data array.  
destination(short) is the terminal to which you should wire the destination buffer if the data you want to  
copy is 16-bit short data array.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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Copy Mem(LV to DSP)  
Copies a buffer of data from the source  
buffer in LabVIEW to the destination  
buffer on the DSP board, which is referred  
to by a DSP Handle Cluster.  
The source buffer can contain one of three  
kinds of data–float (32-bit), short  
(16-bit), and long (32-bit). To copy  
different types of data, you must wire to the  
appropriate source terminal. You must  
wire only one kind of source terminal. The  
destination buffer must be large enough to contain all of the data from the source buffer.  
source(float) is the terminal to which you should wire the source buffer if the data you want to copy is  
32-bit floating point data array.  
source(long) is the terminal to which you should wire the source buffer if the data you want to copy is  
32-bit long data array.  
source(short) is the terminal to which you should wire the source buffer if the data you want to copy is  
16-bit short data array.  
Destination in is a DSP Handle Cluster that indicates the destination memory buffer on the DSP board  
that will contain the data copied from the LabVIEW source buffer.  
Destination out is a DSP Handle Cluster that is identical to Destination in, but with the source buffer  
data already copied to the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Absolute  
th  
Find the absolute value of input array X. The i  
element of the output array Y is obtained using  
the following formula:  
Y(i) = |X(i) |.  
for i = 0, 1, 2, … , n-1  
where n is the number of elements in X.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array X.  
Y in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will contain the  
absolute results of X(i).  
Y out is a DSP Handle Cluster that is identical to Y in, but with the absolute results already stored in the  
memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
The operation can be performed in place; that is, the input and output arrays can be the same DSP Handle Cluster.  
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DSP Add  
th  
Add array X to array Y. The i element of the  
output array Z is obtained using the following  
formula:  
Z(i) = X(i) + Y(i).  
for i = 0, 1, 2, … , n-1  
where n is the smaller number of elements in X and Y.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array X.  
Y is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array Y.  
Z in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will contain the  
results of X(i) + Y(i).  
Z out is a DSP Handle Cluster that is identical to Z in, but with the added results already stored in the  
memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
The operation can be performed in place; that is, the input and output arrays can be the same DSP Handle Cluster.  
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DSP Allocate Memory  
Allocates a block of memory buffer on  
the DSP board specified by slot and  
returns a DSP Handle Cluster that  
contains the coded DSP board memory  
and the number of elements in this  
buffer.  
The number of bytes allocated for this  
buffer depends on size and  
bytes/element selector. If bytes/element selector selects 4 bytes, then the number of bytes = size*4. If  
bytes/element selector selects 2 bytes, then the number of bytes = size*2.  
The allocation routines on the board assure alignment to the nearest 4-byte boundary ≥ number of bytes to guarantee  
memory alignment on 4-byte addresses. For example, if you request to allocate a buffer of size 1,022 or 1,024 bytes,  
the allocation routines allocate 1,024 bytes in both cases.  
slot is the board ID number. slot defaults to 3.  
size is the number of elements to allocate for this buffer. size defaults to 0.  
bytes/element selector specifies the number of bytes per element. It has two options:  
0: 4 bytes.  
1: 2 bytes.  
bytes/element selector defaults to 4 bytes.  
DSP Handle Cluster indicates the allocated memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Blackman Window  
Applies a Blackman window to the input  
sequence X. If Y represents the output  
sequence Blackman{X}, the elements of Y  
are obtained from the following formula:  
yi = xi [0.42 - 0.50 cos(w)  
+ 0.08 cos(2w)]  
for i = 0, 1, 2, … , n-1 ,  
2πi  
w =  
,
n
where n is the number of elements in X.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array.  
Note: The operation is performed in place and the input array X is overwritten by the output  
Blackman {X}.  
Blackman {X} is a DSP Handle Cluster that is identical to X, but with the results of Blackman {X}  
already stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Blackman Harris Window  
Applies a Blackman Harris window to  
the input sequence X. If Y represents  
the output sequence Blackman  
Harris{X}, the elements of Y are  
obtained using the following formula:  
yi = xi [0.42323 - 0.49755 cos(w)  
+0.07922 cos(2w)]  
for i = 0, 1, 2, … , n-1  
2πi  
w =  
,
n
where n is the number of elements in X.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array.  
Note: The operation is performed in place and the input array X is overwritten by the output  
Blackman Harris {X}.  
Blackman Harris {X} is a DSP Handle Cluster that is identical to X, but with the results of Blackman  
Harris {X} already stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Butterworth Coefficients  
Generates the set of filter  
coefficients to implement an  
IIR filter as specified by the  
Butterworth filter model.  
You can then pass these  
coefficients to the DSP IIR  
Filter VI to filter a sequence  
of data.  
filter type specifies the passband of the filter. It has four options:  
0: lowpass.  
1: highpass.  
2: bandpass.  
3: bandstop.  
filter type defaults to lowpass.  
sampling freq : fs is the sampling frequency and must be greater than 0. If it is less than or equal to  
zero, the VI returns an error. sampling freq : fs defaults to 1.0.  
high cutoff freq: fh is the high cutoff frequency. The VI ignores this parameter when filter type is  
lowpass. high cutoff freq: fh defaults to 0.45.  
low cutoff freq: fl is the low cutoff frequency. The VI ignores this parameter when filter type is  
highpass. low cutoff freq: fl defaults to 0.125.  
Note: fh and fl must observe the Nyquist criterion: 0 ≤ fl ≤ fh ≤ fs /2.  
Forward Coefficients in is a DSP Handle Cluster that indicates the memory buffer on the DSP board  
that will contain the forward coefficients.  
Feedback Coefficients in is a DSP Handle Cluster that indicates the memory buffer on the DSP board  
that will contain the feedback coefficients.  
Forward Coefficients out is a DSP Handle Cluster that is identical to the Forward Coefficients in, but  
with the forward coefficients already stored in the memory buffer on the DSP board.  
Feedback coefficients out is aDSP Handle Cluster that is identical to the Feedback Coefficients in, but  
with the feedback coefficients already stored in the memory buffer on the DSP board.  
order must be greater than zero. If order is less than or equal to zero, the VI returns an error. order  
defaults to 2.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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Parameter Discussion  
The arrays Forward Coefficients in/out and Feedback Coefficients in/out must have a size of at least (order + 1)  
for lowpass and highpass filters. The arrays Forward Coefficients in/out and Feedback Coefficients in/out must  
have a size of at least (2*order + 1) for bandpass and bandstop filters.  
DSP Chebyshev Coefficients  
Generates the set of filter  
coefficients to implement an  
IIR filter as specified by the  
Chebyshev filter model.  
You can then pass  
coefficients to the DSP IIR  
Filter VI to filter a sequence  
of data.  
filter type specifies the passband of the filter. It has four options:  
0: lowpass.  
1: highpass.  
2: bandpass.  
3: bandstop.  
filter type defaults to lowpass.  
sampling freq : fs is the sampling frequency and must be greater than 0. If it is less than or equal to  
zero, the VI returns an error. sampling Freq : fs defaults to 1.0.  
high cutoff freq: fh is the high cutoff frequency. The VI ignores this parameter when filter type is  
lowpass. high cutoff freq: fh defaults to 0.45.  
low cutoff freq: fl is the low cutoff frequency. The VI ignores this parameter when filter type is  
highpass. low cutoff freq: fl defaults to 0.125.  
Note: fh and fl must observe the Nyquist criterion: 0 ≤ fl ≤ fh ≤ fs /2.  
ripple must be greater than 0. If ripple is less than or equal to zero, the VI returns an error. ripple  
defaults to 0.1.  
order must be greater than zero. If order is less than or equal to zero, the VI returns an error. order  
defaults to 2.  
Forward Coefficients in is a DSP Handle Cluster that indicates the memory buffer on the DSP board  
that will contain the forward coefficients.  
Feedback Coefficients in is a DSP Handle Cluster that indicates the memory buffer on the DSP board  
that will contain the feedback coefficients.  
Forward Coefficients out is a DSP Handle Cluster that is identical to the Forward Coefficients in, but  
with the forward coefficients already stored in the memory buffer on the DSP board.  
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Feedback Coefficients out is a DSP Handle Cluster that is identical to the Feedback Coefficients in,  
but with the feedback coefficients already stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
Parameter Discussion  
The arrays Forward Coefficients in/out and Feedback Coefficients in/out have to have a size of at least (order +  
1) for lowpass and highpass filters.The arrays Forward Coefficients in/out and Feedback Coefficients in/out have  
to have a size of at least (2*order + 1) for bandpass and bandstop filters.  
DSP Clip  
Clips the input array values. The range of  
the resulting output array is [lower:upper].  
th  
Let Y represent the output array. The i  
element of the resulting array is obtained by  
using the following formulas:  
upper if X(i) > upper  
lower if X(i) < lower  
Y(i) =  
X(i) otherwise  
for i = 0, 1, 2, …, size-1 ,  
where n is the number of elements in X.  
The operation can be performed in place; that is, the input and output arrays can be the same DSP Handle Cluster.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array X.  
upper limit. upper limit ≥ lower limit. upper limit defaults to 1.0.  
lower limit. lower limit defaults to 0.0.  
Clipped{X} in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will  
contain the output array of Clipped{X}.  
Clipped{X} out is a DSP Handle Cluster that is identical to Clipped {X} in, but with the Clipped{X}  
already stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Complex FFT  
Computes the Fast Fourier transform of  
the complex input sequence X. If Y  
represents the complex output sequence,  
then:  
Y = F{X}.  
Re{X} is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the real  
part of the input signal array X.  
Im{X} is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the  
imaginary part of input signal array X.  
Notes: The number of elements for the input array must be a power of 2.  
If the size of Re{X} is different from the size of Im{X}, the VI uses the smaller number as the  
size of the Complex FFT.  
The operation is performed in place and the input array Re{X} and Im{X} is overwritten by the  
Re FFT{X} and Im FFT{X}.  
The largest complex FFT that can be computed depends upon the amount of memory on your  
board.  
Re FFT{X} is a DSP Handle Cluster that is identical to Re{X}, but with the real part of FFT{X}already  
stored in the memory buffer on the DSP board.  
Im FFT{X} is a DSP Handle Cluster that is identical to Im{X}, but with the imaginary part of  
FFT{X}already stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Convolution  
Computes the convolution of the input  
sequences X and Y. The convolution Cxy(t), of  
the signals x(t) and y(t), is defined as follows:  
∞
Cxy(t) = x(t) y(t) = ∫ x(τ) y(t-τ) dτ,  
*
-∞  
where the symbol denotes convolution.  
*
For the discrete implementation of the convolution, let Cxy represent the output sequence X * Y, n be the number of  
elements in the input sequence X, and m be the number of elements in the input sequence Y. Assuming that indexed  
elements of X and Y that lie outside their range are zero,  
xi = 0,  
yj = 0,  
i < 0 or i ≥ n  
and  
j < 0 or j ≥ m,  
then you obtain the elements of Cxy using:  
n-1  
Cxy =  
x y  
for i = 0, 1, 2, …, size-1 ,  
∑
i
k i-k  
k = 0  
size = n + m - 1,  
where size is the total number of elements in the output sequence X * Y.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array X.  
Y is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array Y.  
Cxy in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will contain the  
convolution of X with Y.  
Note: The size of Cxy in must be (n+m-1) elements long. n is the size of X, m is the size of Y. You  
cannot perform the operation in place.  
Cxy out is a DSP Handle Cluster that is identical to the Cxy in but with the convolution of X and Y  
already stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Correlation  
Computes the cross correlation of the input  
sequences X and Y. The cross correlation Rxy(t)  
of the signals x(t) and y(t) is defined as follows:  
∞
Rxy(t) = x(t) ⊗ y(t) = x(t) y(t+t) dt ,  
∫
-∞  
where the symbol ⊗ denotes correlation.  
For the discrete implementation of the correlation, let Rxy represent the output sequence X ⊗ Y, n be the number of  
elements in the input sequence X, and m be the number of elements in the input sequence Y. You then obtain the  
elements of Rxy using the following formula:  
n-1  
R
=
x[k] y[k+m-1]  
for i = 0, 1, 2, …, m+n-1 ,  
∑
xy i  
k=0  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array X.  
Y is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array Y.  
Rxy in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will contain the  
correlation results.  
Note: The size of Rxy in must be at least (n+m-1) elements long. n is the size of X, m is the size  
of Y.  
Rxy out is a DSP Handle Cluster that is identical to the Rxy in, but with the correlation of X and Y  
already stored in the memory buffer on the DSP board.  
Note: If X and Y are the same array, an auto correlation is performed, otherwise, a cross correlation is  
performed. You cannot perform the operation in place.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Cross Power  
Computes the cross power spectrum of the input  
sequences X and Y. The cross power, Sxy(f), of  
the signals x(t) and y(t) is defined as follows:  
Sxy(f) = X*(f)Y(f)  
*
where X (f) is the complex conjugate of X(f),  
X(f) = F{x(t)}, and  
Y(f) = F{y(t)}.  
This VI uses the FFT routine to compute the cross power spectrum, that is given by the following formula:  
1
n
*
S
=
F {X} F{Y} ,  
xy  
2
k
n = 2  
for k = 1, 2, 3, …, 23,  
where S represents the complex output sequence Sxy, and  
xy  
n is the number of samples that can accommodate both input sequences X and Y.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array X.  
Y is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array Y.  
Notes: If the size of X is different than Y, the VI uses the smaller number as the size of input arrays X  
and Y. The number of elements for the input arrays must be a power of two.  
The operation is performed in place and the input arrays X and Y are overwritten by the  
outputs Re{Sxy} and Im{Sxy}.  
The largest Cross Power Spectrum that can be computed depends upon the amount of memory  
in your DSP board.  
This VI allocates a temporary workspace on the DSP board equal to the size of the input signal  
array.  
Re{Sxy} is a DSP Handle Cluster that is identical to X, but with the real part of Sxy already stored in the  
memory buffer on the DSP board.  
Im{Sxy} is a DSP Handle Cluster that is identical to Y, but with the imaginary part of Sxy already  
stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Custom  
Use this VI as the interface to  
call your own custom functions  
written on the DSP board from  
LabVIEW. For more details  
about how to use this VI, refer  
to Part 4, NI-DSP Interface  
Utilities, of this manual.  
slot is the board ID number. slot defaults to 3.  
function code indicates which function on the DSP board LabVIEW is calling. function code defaults  
to 0.  
Array of Handles in is an array of DSP Handle Clusters that hold all of the references to the input and  
output data buffers used in your custom functions on the DSP board.  
Array of SGL Scalars in is an array of 32-bit floating-point scalars that hold all of the input 32-bit  
floating-point scalars used in your custom functions on the DSP board.  
Array of I32 Scalars in is an array of 32-bit long integer scalars that hold all of the input 32-bit long  
integer scalars used in your custom functions on the DSP board.  
Array of Handles out is an array of DSP Handle Clusters that is identical to Array of Handles in, but  
with the output results already stored in the memory buffers on the DSP board.  
Array of SGL Scalars out is an array of 32-bit floating-point scalars that is identical to Array of SGL  
Scalars in, but with the output results already stored in the array.  
Array of I32 Scalars out is an array of 32-bit long integer scalars that is identical to Array of I32  
Scalars in, but with the output results already stored in the array.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Decimate  
Decimates the input sequence X by the  
decimating factor and the averaging control.  
If Y represents the output sequence Decimated  
Array, the elements of the sequence Y are  
obtained using:  
Xim  
if ave = no averaging  
m−1  
Yi =  
1
X
if ave = averaging  
∑
i(m+k)  
m k=0  
for i = 0, 1, 2, …, size -1  
n
size = trunc  
,
(m)  
where n is the number of elements in X,  
m is the decimating factor,  
ave is the averaging option, and  
size is the number of elements in the output sequence Y.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array.  
Y in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will contain the  
decimated output array.  
Y out is a DSP Handle Cluster that is identical to Y in, but with the results of the decimated array  
already stored in the memory buffer on the DSP board.  
decimating factor must be greater than zero:  
0 < decimating factor ≤ n.  
If decimating factor is greater than the number of samples in X or less than or equal to zero, the VI  
returns an error. decimating factor defaults to 1.  
averaging has two options:  
0: averaging.  
1: no averaging.  
averaging defaults to no averaging.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
The operation can be performed in place; that is, the input X and the output Y can be the same DSP Handle Cluster.  
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DSP Deconvolution  
Computes the deconvolution of the input  
sequences X and Y. The convolution operation  
can be realized using Fourier identities because  
x(t) y(t) ⇔ X(f) Y(f)  
*
is a Fourier transform pair, where the symbol  
denotes convolution, and the deconvolution is  
*
the inverse of the convolution operation. If h(t) is the signal resulting from the deconvolution of the signals x(t) and  
y(t), the VI obtains h(t) using the equation  
X(f)  
{Y(f)}  
-1  
h(t) = F  
,
where X(f) is the Fourier transform of x(t), and  
Y(f) is the Fourier transform of y(t).  
The VI performs the discrete implementation of the deconvolution using the following steps.  
1. Compute the Fourier transform of the input sequence X * Y.  
2. Compute the Fourier transform of the input sequence Y.  
3. Divide the Fourier transform of X * Y by the Fourier transform of Y. Call the new sequence H.  
4. Compute the inverse Fourier transform of H to obtain the deconvoluted sequence X.  
Cxy is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array Cxy. The number of elements in Cxy must be greater than or equal to the number of  
elements in Y.  
Y is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array Y.  
X in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will contain the  
deconvolution results.  
Note: The size of X in must be n elements long, although only (n-m+1) elements are valid. n is the  
size of Cxy, m is the size of Y.  
X out is a DSP Handle Cluster that is identical to X in, but with the deconvolution results already stored  
in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
Note: The deconvolution operation is a numerically unstable operation, and it is not always possible to solve the  
system numerically. Computing the deconvolution via FFTs is perhaps the most stable generic algorithm  
that does not require sophisticated DSP techniques. However, it is not free of errors (for example, when  
there are zeros in the Fourier transform of the input sequence Y).  
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DSP Derivative  
Performs a discrete differentiation of the  
sampled signal X. The differentiation f(t) of a  
function F(t) is defined as follows:  
d
dt  
f(t) =  
F(t).  
Let Y represent the sampled output sequence  
d/dt X. The discrete implementation is given  
by the following formula:  
1
2dt  
yi =  
(xi+1 - xi-1)  
for i = 0, 1, 2, …, n-1.  
where n is the number of samples in x(t)  
x-1 is specified by initial condition when i = 0, and  
xn is specified by final condition when i = n-1.  
initial condition and final condition minimize the error at the boundaries.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array.  
initial condition defaults to 0.0.  
final condition defaults to 0.0.  
dt is the sampling interval and must be greater than zero. If dt is less than or equal to zero, the VI  
returns an error. dt defaults to 1.0.  
Y in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will contain the  
results of the differentiation of X.  
Y out is a DSP Handle Cluster that is identical to Y in, but with the results of differentiation already  
stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
The operation can be performed in place; that is, the input X and the output Y can be the same DSP Handle Cluster.  
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DSP Divide  
th  
Divide array X by array Y. The i element of  
the output array Z is obtained using the  
following formula:  
Z(i) = X(i) / Y(i).  
for i = 0, 1, 2, …, n-1.  
where n is the smaller number of elements in  
X and Y.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array X.  
Y is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array Y.  
Z in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will contain the  
results of X(i) / Y(i).  
Z out is a DSP Handle Cluster that is identical to Z in, but with the divided results already stored in the  
memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
The operation can be performed in place; that is, the input and the output arrays can be the same DSP Handle  
Cluster.  
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DSP Elliptic Coefficients  
Generates the set of filter  
coefficients to implement a  
digital elliptic IIR filter. You  
can then pass these  
coefficients to the DSP IIR  
Filter VI.  
filter type specifies the passband of the filter. filter type has four options:  
0: lowpass.  
1: highpass.  
2: bandpass.  
3: bandstop.  
filter type defaults to lowpass.  
sampling freq : fs is the sampling frequency and must be greater than 0. If it is less than or equal to  
zero, the VI returns an error. sampling freq : fs defaults to 1.0.  
high cutoff freq: fh is the high cutoff frequency. The VI ignores this parameter when filter type is  
lowpass. high cutoff freq: fh defaults to 0.45.  
low cutoff freq: fl is the low cutoff frequency. The VI ignores this parameter when filter type is  
highpass. high cutoff freq: fh defaults to 0.125.  
Note: fh and fl must observe the Nyquist criterion: 0 ≤ fl ≤ fh ≤ fs /2.  
passband ripple must be greater than 0, and you must express it in decibels. If passband ripple is less  
than or equal to zero, the VI returns an error. passband ripple defaults to 1.0.  
order must be greater than zero. If order is less than or equal to zero, the VI returns an error. order  
defaults to 2.  
stopband attenuation must be greater than 0, and you must express it in decibels. If stopband  
attenuation is less than or equal to zero, the VI returns an error. stopband attenuation defaults to 60.0.  
Forward Coefficients in is a DSP Handle Cluster that indicates the memory buffer on the DSP board  
that will contain the forward coefficients.  
Feedback Coefficients in is a DSP Handle Cluster that indicates the memory buffer on the DSP board  
that will contain the feedback coefficients.  
Forward Coefficients out is a DSP Handle Cluster that is identical to Forward Coefficients in, but  
with the forward coefficients already stored in the memory buffer on the DSP board.  
Feedback Coefficients out is a DSP Handle Cluster that is identical to Feedback Coefficients in, but  
with the feedback coefficients already stored in the memory buffer on the DSP board.  
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error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
Parameter Discussion  
The arrays Forward Coefficients in/out and Feedback Coefficients in/out must have a size of at least (order + 1)  
for lowpass and highpass filters. The arrays Forward Coefficients in/out and Feedback Coefficients in/out must  
have a size of at least (2*order + 1) for bandpass and bandstop filters.  
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DSP Equi-Ripple BandPass  
Generates a bandpass FIR filter  
with equi-ripple characteristics  
using the Parks-McClellan  
algorithm and the number of taps,  
lower stop frequency, higher stop  
frequency, lower pass frequency,  
higher pass frequency, and  
sampling frequency. The VI then  
filters the input sequence X to  
obtain the bandpass filtered linear-  
phase sequence Filtered Data.  
The first stopband of the filter  
region goes from zero (DC) to the  
lower stop frequency. The passband region goes from the lower pass frequency to the higher pass frequency, and  
the second stopband region goes from the higher stop frequency to the Nyquist frequency.  
higher pass freq must be greater than lower pass freq frequency. If higher pass freq is less than or  
equal to lower pass freq, the VI returns an error. higher pass freq defaults to 0.3.  
lower pass freq must be greater than the lower stop freq. If lower pass freq is less than or equal to  
lower stop freq, the VI returns an error. lower pass freq defaults to 0.2.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
data array.  
# of taps must be greater than 0. If the number of taps is less than or equal to zero, the VI returns an  
error. # of taps defaults to 32.  
lower stop freq must be greater than zero. If lower stop freq is less than or equal to zero, the VI  
returns an error. lower stop freq defaults to 0.1.  
higher stop freq must be greater than higher pass freq and must observe the Nyquist criterion:  
0 < f0 < f1 < f2 < f3 ≤ 0.5fs ,  
where f0 is lower stop freq, f1 is lower pass freq, f2 is higher pass freq, f3 is the higher stop freq, and  
fs is the sampling frequency. If any of these conditions is violated, the VI returns an error. higher stop  
freq defaults to 0.4.  
sampling freq: fs defaults to 1.0.  
Filtered Data in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will  
contain the filtered data output.  
Filtered Data out is a DSP Handle Cluster that is identical to Filtered Data in, but with the filtered  
data already stored in the memory buffer on the DSP board. Because the VI filters via convolution, the  
number of elements, k, in Filtered Data is as follows:  
k = n + m - 1,  
where n is the number of elements in X, and m is the number of taps.  
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A delay is also associated with the output sequence  
m-1  
2
delay =  
.
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
The operation cannot be performed in place; that is, the input X and the output Filtered Data cannot be the same  
DSP Handle Cluster.  
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DSP Equi-Ripple BandStop  
Generates a bandstop FIR digital filter  
with equi-ripple characteristics using the  
Parks-McClellan algorithm and number  
of taps, lower pass frequency, higher  
pass frequency, lower stop frequency,  
higher stop frequency, and sampling  
frequency. The VI then filters the input  
sequence X to obtain the bandstop  
filtered linear-phase sequence Filtered  
Data.  
The first passband region of the filter  
goes from zero (DC) to the lower pass  
frequency. The stopband region goes  
from the lower stop frequency to the higher stop frequency, and the second passband region goes from the higher  
pass frequency to the Nyquist frequency.  
higher pass freq must be greater than higher stop freq and observe the Nyquist criterion:  
0 < f0 < f1 < f2 < f3 ≤ 0.5fs,  
where f0 is the lower pass freq, f1 is the lower stop freq, f2 is the higher stop freq, f3 is the higher pass  
freq, and fs is the sampling freq. If any of these conditions is violated, the VI returns an error. higher  
pass freq defaults to 0.4.  
lower pass freq must be greater than zero. If lower pass freq is less than or equal to 0, the VI returns  
an error. lower pass freq defaults to 0.1.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
data array.  
# of taps must be odd and must be greater than 0. If the number of taps is an even number or is less  
than or equal to zero, the VI returns an error. # of taps defaults to 31.  
lower stop freq must be greater than lower pass freq. If lower stop freq is less than or equal to lower  
pass freq, the VI returns an error. lower stop freq defaults to 0.2.  
higher stop freq must be greater than lower stop freq. If higher stop freq is less than or equal to  
lower stop freq, the VI returns an error. higher stop freq defaults to 0.3.  
sampling freq: fs defaults to 1.0.  
Filtered Data in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will  
contain the filtered data output.  
Filtered Data out is a DSP Handle Cluster that is identical to Filtered Data in, but with the filtered  
data already stored in the memory buffer on the DSP board. Because the VI filters via convolution, the  
number of elements, k, in Filtered Data is as follows:  
k = n + m - 1,  
where n is the number of elements in X, and m is the number of taps.  
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A delay is also associated with the output sequence:  
m-1  
2
delay =  
.
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
The operation cannot be performed in place; that is, the input X and the output Filtered Data cannot be the same  
DSP Handle Cluster.  
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DSP Equi-Ripple HighPass  
Generates a highpass FIR filter with  
equi-ripple characteristics using the  
Parks-McClellan algorithm and the  
number of taps, high frequency, stop  
frequency, and sampling frequency. The  
VI then filters the input sequence X to  
obtain the highpass filtered linear-phase  
sequence Filtered Data.  
The stopband of the filter goes from zero  
(DC) to the stop frequency. The  
transition band goes from the stop  
frequency to the high frequency, and  
the passband goes from the high frequency to the Nyquist frequency.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
data array.  
# of taps must be greater than 0 and must be an odd number. If the number of taps is an even number or  
is less than or equal to zero, the VI returns an error. # of taps defaults to 31.  
stop freq must be greater than zero. If stop freq is less than or equal to 0, the VI returns an error. stop  
freq defaults to 0.2.  
high freq must be greater than stop freq and observe the Nyquist criterion:  
0 < f0 < f1 ≤ 0.5fs,  
where f0 is the stop freq, f1 is the high freq, and fs is the sampling frequency. If any of these conditions  
is violated, the VI returns an error. high freq defaults to 0.3.  
sampling freq: fs defaults to 1.0.  
Filtered Data in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will  
contain the filtered data output.  
Filtered Data out is a DSP Handle Cluster that is identical to Filtered Data in, but with the filtered  
data already stored in the memory buffer on the DSP board. Because the VI filters via convolution, the  
number of elements, k, in Filtered Data is:  
k = n + m - 1,  
where n is the number of elements in X, and m is the number of taps.  
A delay is also associated with the output sequence:  
m-1  
2
delay =  
.
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error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
The operation cannot be performed in place; that is, the input X and the output Filtered Data out cannot be the  
same DSP Handle Cluster.  
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DSP Equi-Ripple LowPass  
Generates a lowpass FIR filter with equi-  
ripple characteristics using the Parks-  
McClellan algorithm and the number of  
taps, pass frequency, stop frequency, and  
sampling frequency. The VI then filters  
the input sequence X to obtain the  
lowpass filtered linear-phase sequence  
Filtered Data.  
The passband of the filter goes from zero  
(DC) to pass freq. The transition band  
goes from pass freq to stop freq, and  
the stopband goes from stop freq to the  
Nyquist frequency.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
data array.  
# of Taps must be greater than 0. If the number of taps is less than or equal to zero, the VI returns an  
error. # of Taps defaults to 31.  
pass freq must be greater than 0. If pass freq is less than or equal to zero, the VI returns an error. pass  
freq defaults to 0.2.  
stop freq must be greater than the pass freq and observe the Nyquist criterion:  
0 < f0 < f1 ≤ 0.5fs,  
where f0 is the pass freq, f1 is the stop freq, and fs is the sampling frequency. If any of these conditions  
is violated, the VI returns an error. stop freq defaults to 0.3.  
sampling freq: fs defaults to 1.0.  
Filtered Data in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will  
contain the filtered data output.  
Filtered Data out is a DSP Handle Cluster that is identical to Filtered Data in, but with the filtered  
data already stored in the memory buffer on the DSP board. Because the VI filters via convolution, the  
number of elements, k, in Filtered Data out is:  
k = n + m - 1,  
where n is the number of elements in X, and  
m is the number of taps.  
m-1  
2
A delay equal to  
is also associated with the output sequence.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
The operation cannot be performed in place; that is, the input X and the output Filtered Data cannot be the same  
DSP Handle Cluster.  
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DSP Exact Blackman Window  
Applies an Exact Blackman window to  
the input sequence X. If Y represents  
the output sequence Exact  
Blackman{X}, the elements of Y are  
obtained using the formula:  
yi = xi [0.42659071  
- 0.49656062 cos(w)  
+ 0.07684867 cos(2w)]  
for i = 0, 1, 2, … , n-1  
2πi  
w =  
,
n
where n is the number of elements in X.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array.  
Note: The operation is performed in place and the input array X is overwritten by the output Exact  
Blackman {X}.  
Exact Blackman {X} is a DSP Handle Cluster that is identical to X, but with the results of Exact  
Blackman {X} already stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Exponential Window  
Applies an exponential window to the input  
sequence X. If Y represents the output  
sequence Exponential{X}, the elements of  
Y are obtained using the formula:  
yi = xi exp(a * i)  
for i = 0, 1, 2, … , n-1,  
ln |f|  
a =  
,
n - 1  
where f is the final value, and  
n is the number of elements in X.  
You can use the Exponential Window VI to analyze transients.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array.  
Note: The operation is performed in place and the input array X is overwritten by the output  
Exponential {X}.  
final value defaults to 0.10.  
Exponential {X} is a DSP Handle Cluster that is identical to X, but with the results of Exponential {X}  
already stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP FHT  
Computes the fast Hartley transform (FHT) of  
the input sequence X. The Hartley transform  
of a function x(t) is defined as follows:  
∞
X(f) = ∫ x(t) cas(2πft) dt  
-∞  
where cas(x) = cos(x) + sin(x).  
If Y represents the output sequence FHT {X} obtained via the FHT, then Y is obtained through the discrete  
implementation of the Hartley integral:  
n-1  
2π ik  
( n )  
Yk =  
Xi cas  
,
for k = 0, 1, 2, … , n-1 .  
∑
i=0  
where n is the number of elements in X.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array.  
Notes: The number of elements for the input array must be a power of two.  
The operation is performed in place and the input array X is overwritten by the output  
FHT{X}.  
The largest FHT that can be computed depends upon the amount of memory on your DSP  
board.  
FHT{X} is a DSP Handle Cluster that is identical to X, but with the results of FHT{X} already stored in  
the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
The Hartley transform maps real-valued sequences into real-valued frequency domain sequences. You can use it  
instead of the Fourier transform to convolve signals, deconvolve signals, correlate signals, and find the power  
spectrum. Furthermore, you can derive the Fourier transform from the Hartley transform.  
When the sequences to be processed are real-valued sequences, the Fourier transform produces complex-valued  
sequences in which half of the information is redundant. The advantage of using the Hartley transform instead of  
the Fourier transform is that the Hartley transform uses half the memory to produce the same information the FFT  
produces. Further, the FHT is calculated in place and is as efficient as the Fourier transform.  
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DSP Flat Top Window  
Applies a flat top window to the input sequence  
X. If Y represents the output sequence  
Flattop{X}, the elements of Y are obtained  
using the formula:  
yi = xi [0.2810639 - 0.5208972 cos(w)  
+ 0.1980399 cos(2w)]  
for i = 0, 1, 2, … , n-1  
2πi  
n
w =  
,
where n is the number of elements in X.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array.  
Note: The operation is performed in place and the input array X is overwritten by the output  
Flattop {X}.  
Flattop {X} is a DSP Handle Cluster that is identical to X, but with the results of Flattop {X} already  
stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Force Window  
Applies a force window to the input sequence X  
If Y represents the output sequence Force{X},  
the elements of Y are obtained using the  
formula:  
x i if 0 ≤ i ≤ d  
yi =  
0
elsewhere  
for i = 0, 1, 2, …, n-1 ,  
d = (0.01)(n)(duty)  
where n is the number of elements in X.  
You can use the Force Window VI to analyze transients.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array.  
Note: The operation is performed in place and the input array X is overwritten by the output  
Force {X}.  
duty. 0.0 ≤ duty ≤ 100.0. duty defaults to 50.0.  
Force {X} is a DSP Handle Cluster that is identical to X, but with the results of Force {X} already  
stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
DSP Free Memory  
Frees the memory space referred by DSP  
Handle Cluster on the specified DSP board.  
DSP Handle Cluster is a DSP Handle Cluster that indicates the memory buffer to free.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and the VI also frees the DSP Handle Cluster.  
error out contains the error information for this call.  
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DSP Gaussian White Noise  
Generates a Gaussian distributed  
pseudorandom pattern whose  
statistical profile is as follows:  
(µ, σ) = (0, s) ,  
where s is the absolute value of the  
specified standard deviation.  
standard deviation defaults to 1.0.  
seed < 65536.0. If seed > 0.0, the generated noise will be the same in repeated invocations if the seed  
value does not change. If seed ≤ 0.0, the VI generates a random value to use as the seed, and the noise  
will differ in repeated invocations although the value in seed does not change. seed defaults to 0.0.  
Gaussian Pattern in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that  
will contain the output Gaussian pattern.  
Gaussian Pattern out is a DSP Handle Cluster that is identical to Gaussian Pattern in, but with the  
generated pattern already stored in the memory buffer on the DSP board. The largest Gaussian pattern  
that can be generated depends upon the amount of memory on your DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP General Cosine Window  
Applies a general cosine window to the input  
sequence X. If A represents the Cosine  
Coefficients input sequence and Y represents  
the output sequence GenCos{X}, the elements  
of Y are obtained using the formula:  
yi = xi m-1 (-1)k a cos (kw)  
∑
k
k=0  
for i = 0, 1, 2, … , n-1  
2πi  
n
w =  
,
where n is the number of elements in X, and  
m is the number of elements in Cosine Coefficients.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array.  
Note: The operation is performed in place and the input array X is overwritten by the output  
GenCos {X}.  
Cosine Coefficients is a DSP Handle Cluster that indicates the memory buffer on the DSP board that  
contains the cosine coefficients.  
GenCos {X} is a DSP Handle Cluster that is identical to X, but with the results of GenCos {X} already  
stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Hamming Window  
Applies a Hamming window to the input  
sequence X. If Y represents the output  
sequence Hamming {X}, the elements of Y  
are obtained from the formula:  
y = x [0.54 - 0.46 cos(w)]  
i
i
for i = 0, 1, 2, …, n-1 ,  
2πi  
n
w =  
,
where n is the number of elements in the input sequence X.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
data array.  
Note: The operation is performed in place and the input array X is overwritten by the output  
Hamming {X}.  
Hamming {X} is a DSP Handle Cluster that is identical to X, but with the results of Hamming {X}  
already stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Handle To Address  
Finds the actual DSP address value of  
DSP Handle Cluster that indicates a  
memory buffer on the DSP board.  
You can use the output DSP Address as  
the input of the DSP Address terminal in  
the DSP DMA Copy(DSP to LV) VI or  
the DSP DMA Copy(LV to DSP) VI.  
DSP Handle Cluster indicates a memory buffer on the DSP board.  
DSP Address is the actual DSP address of the memory buffer on the DSP board referred to by DSP  
Handle Cluster.  
error in(no error) contains the error information from a previous VI. If an error occurs, it is passed  
out error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Hanning Window  
Applies a Hanning window to the input  
sequence X. If Y represents the output  
sequence Hanning {X}, the elements of Y are  
obtained using the formula:  
yi = 0.5 xi [1 - cos(w)]  
for i = 0, 1, 2, …, n-1 ,  
2πi  
n
w =  
,
where n is the number of elements in the input sequence X.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
data array.  
Note: The operation is performed in place and the input array X is overwritten by the output  
Hanning {X}.  
Hanning {X} is a DSP Handle Cluster that is identical to X, but with the results of Hanning {X} already  
stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP IIR Filter  
Performs IIR filtering on the  
X input array and reports the  
result in Y. It uses the arrays  
a and b of sizes sza and szb  
respectively in implementing  
the linear difference equation  
that describes IIR filtering:  
k = sza - 1  
k = szb-1  
y[i] = ∑ a(k) * x(i-k) - ∑ b(k) * y(i-k)  
i = 0,1 ..... ,n-1  
k = 0  
k = 1  
where:  
a is the array of forward coefficients describing an IIR filter (obtained from DSP Butterworth Coefficients  
VI for example)  
b is the array of feedback coefficients describing an IIR filter (obtained from the same filter design VI)  
Notes: b(0) = 1.0in the above equation.  
This VI may be called in a loop to perform filtering on data frames that are part of the same data stream.  
At time i = 0, the initial conditions on X (for example, X(1-sza)through X(-1)) are obtained from the array  
Initial Conditions on input. At exit (the end of the VI execution), this array holds the final conditions on  
X that could be used as the initial conditions for the next DSP IIR Filter VI call if you were to call it in a  
loop.  
At time i = 0, the initial conditions on Y (for example, Y(1-szb) through Y(-1)) are obtained from the array  
Initial Conditions on output. At exit (the end of the VI execution), this array holds the final conditions on  
Y that could be used as the initial conditions for the next DSP IIR Filter VI call if you were to call it in a  
loop.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array.  
Y in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will contain the  
output array of filtered data.  
Initial Conditions on input is a DSP Handle Cluster that indicates the memory buffer on the DSP board  
that contains the initial conditions on input at time zero.  
Initial Conditions on output is a DSP Handle Cluster that indicates the memory buffer on the DSP  
board that contains the initial conditions on output at time zero.  
Forward Coefficients is a DSP Handle Cluster that indicates the memory buffer on the DSP board that  
contains the forward coefficients of the IIR filter.  
Feedback Coefficients is a DSP Handle Cluster that indicates the memory buffer on the DSP board that  
contains the feedback coefficients of the IIR filter.  
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Y out is a DSP Handle Cluster that is identical to Y in, but with the filtered data already stored in the  
memory buffer on the DSP board.  
Final Conditions on input is a DSP Handle Cluster that is identical to Initial Conditions on input, but  
contains the final conditions on input.  
Final Conditions on output is a DSP Handle Cluster that is identical to Initial Conditions on output,  
but contains the final conditions on output.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
The operation can be performed in place; that is, the input X and the output Y can be the same DSP Handle Cluster.  
Parameter Discussion  
The arrays X and Y should be the same size. The arrays Forward Coefficients and Initial/Final Conditions on  
input should be the same size. The arrays Feedback Coefficients and Initial/Final Conditions on output should  
be the same size. In successive calls to this VI, while performing filtering on large data streams, one buffer at a  
time, the final conditions of the filter are stored in Final Condition on input and in Final Condition on output, and  
are used as the initial conditions of the filter in the subsequent call. For example, if you designed a filter with all of  
the initial conditions set to zero, and you then wanted to filter a stream of 8,192 data points, 1,024 points at a time,  
after the first call, the final conditions of the filter are stored in Final Condition on input and in Final Condition  
on output. These can be used as the initial conditions to the filter in the filtering of the next 1,024 points, and so on.  
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DSP Impulse Pattern  
Generates an array containing an  
impulse pattern. If the Impulse  
Pattern is represented by the  
sequence X, the VI generates the  
pattern according to the following  
formula:  
a
if i = d  
xi =  
0
elsewhere  
for i = 0, 1, 2, … , n-1 ,  
where a is the amplitude,  
d is the delay, and  
n is the number of elements in Impulse Pattern.  
amplitude defaults to 1.0.  
delay must be greater than or equal to 0. If delay is less than zero or greater than or equal to the size of  
Impulse Pattern, the VI returns an error. delay defaults to 0.  
Impulse Pattern in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that  
will contain the output impulse pattern.  
Impulse Pattern out is a DSP Handle Cluster that is identical to Impulse Pattern in, but with the  
generated pattern already stored in the memory buffer on the DSP board. The largest impulse pattern  
that can be generated depends upon the amount of memory on your DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Impulse Train Pattern  
Generates a train of impulses of value  
amplitude at sample delay.  
If the impulse train pattern is represented  
by the sequence X, the VI generates the  
pattern according to the following  
formula:  
amplitude if i modulo P = d  
xi =  
0.0 elsewhere  
for i = 0, 1, 2, … , n-1 ,  
where P is the period,  
d is the delay, and  
n is the number of elements in the impulse train.  
amplitude defaults to 1.0.  
delay defaults to 0.  
period defaults to 1.  
Impulse Train in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will  
contain the output impulse train.  
Impulse Train out is a DSP Handle Cluster that is identical to Impulse Train in, but with the generated  
pattern already stored in the memory buffer on the DSP board. The largest impulse train that can be  
generated depends upon the amount of memory on your DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Index Memory  
Indexes into a DSP buffer  
allocated in the memory  
space of the specified DSP  
board. The return value is  
another DSP Handle Cluster.  
This VI does not allocate  
memory.  
In order to index into a buffer  
correctly, you need to indicate  
what type of data is in the DSP  
buffer. You must set data type to the appropriate type. data type has two options–4 bytes (for 32-bit long and  
floating-point data) and 2 bytes (for 16-bit short data).  
DSP Handle Cluster is a DSP Handle Cluster into which you want to index.  
data type indicates the type of data in the buffer on the DSP board that is referred to by DSP Handle  
Cluster. data type has two options:  
0: 4 bytes (for 32-bit long and floating-point data).  
1: 2 bytes (for 16-bit short data).  
data type defaults to 4 bytes.  
offset is the index where to start to index into the array referenced by DSP Handle Cluster. offset  
defaults to 0.  
Indexed DSP Handle Cluster is a DSP Handle Cluster that contains the number of size data in DSP  
Handle Cluster starting from offset.  
Notes: If you free a DSP Handle Cluster using the DSP Free Memory VI, then all other DSP Handle  
Clusters obtained by using DSP Index Memory VI will no longer be valid.  
This VI returns a new DSP Handle Cluster. If you no longer need this DSP Handle Cluster,  
remember to free it.  
size indicates how many elements you want to index starting from the offset. size defaults to 0.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Init Memory  
Initializes the memory heaps and frees all  
allocations of memory on the specified DSP  
board.  
slot is the board ID number. slot defaults to 3.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Integral  
Performs the discrete integration of the  
sampled signal X. The integral F(t) of a  
function f(t) is defined as follows:  
F(t) = ∫ f(t) dt .  
Let Y represent the sampled output sequence Integral X. The VI obtains the elements of Y using the following  
formula:  
i
1
6
yi =  
(xj-1 + 4xj + xj+1) dt  
for i = 0, 1, 2, …, n-1 ,  
∑
j=0  
where n is the number of elements in X,  
x-1 is specified by initial condition when i = 0, and  
xn is specified by final condition when i = n-1.  
The initial condition and final condition minimize the overall error by increasing the accuracy at the boundaries,  
especially when the number of samples is small. Determining boundary conditions before the fact enhances  
accuracy.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array.  
initial condition defaults to 0.0.  
final condition defaults to 0.0.  
dt is the sampling interval and must be greater than zero. If dt is less than or equal to zero, the VI  
returns an error. dt defaults to 1.0.  
Y in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will contain the  
results of the integration of X.  
Y out is a DSP Handle Cluster that is identical to Y in, but with the results of integration already stored  
in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
The operation can be performed in place; that is, the input X and the output Y can be the same DSP Handle Cluster.  
Note: You can also use the DSP Integral x(t) VI to numerically evaluate the finite integral:  
b
∫ f(t) dt = F(b) - F(a) ≈ yn-1  
,
a
by extracting the last element of the output sequence Y.  
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DSP Inv Chebyshev Coeff  
Generates the set of filter  
coefficients to implement an  
inverse IIR filter as specified  
by the Chebyshev II Filter  
mode. You can then pass  
these coefficients to the DSP  
IIR Filter VI to filter a  
sequence of data.  
filter type specifies the passband of the filter. filter type has four options:  
0: lowpass.  
1: highpass.  
2: bandpass.  
3: bandstop.  
filter type defaults to lowpass.  
sampling Freq : fs is the sampling frequency and must be greater than 0. If it is less than or equal to  
zero, the VI returns an error. sampling Freq : fs defaults to 1.0.  
high cutoff freq: fh is the high cutoff frequency. The VI ignores this parameter when filter type is  
lowpass. high cutoff freq: fh defaults to 0.45.  
low cutoff freq: fl is the low cutoff frequency. The VI ignores this parameter when filter type is  
highpass. low cutoff freq: fl defaults to 0.125.  
Note: fh and fl must observe the Nyquist criterion: 0 ≤ fl ≤ fh ≤ fs /2.  
attenuation must be greater than 0.0. If attenuation is less than or equal to zero, the VI returns an  
error. attenuation defaults to 60.0.  
order must be greater than zero. If the filter order is less than or equal to zero, the VI returns an error.  
order defaults to 2.  
Forward Coefficients in is a DSP Handle Cluster that indicates the memory buffer on the DSP board  
that will contain the forward coefficients.  
Feedback Coefficients in is a DSP Handle Cluster that indicates the memory buffer on the DSP board  
that will contain the feedback coefficients.  
Forward Coefficients out is a DSP Handle Cluster that is identical to Forward Coefficients in, but  
with the forward coefficients already stored in the memory buffer on the DSP board.  
Feedback Coefficients out is a DSP Handle Cluster that is identical to Feedback Coefficients in, but  
with the feedback coefficients already stored in the memory buffer on the DSP board.  
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error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
Parameter Discussion  
The arrays Forward Coefficients in/out and Feedback Coefficients in/out must have a size of at least (order + 1)  
for lowpass and highpass filters. The arrays Forward Coefficients in/out and Feedback Coefficients in/out must  
have a size of at least (2*order + 1) for bandpass and bandstop filters.  
DSP Inverse FFT  
Computes the inverse Fourier transform of the  
complex input sequence FFT {X}. If Y  
represents the output sequence, then:  
-1  
Y = F {X}.  
Re FFT{X} is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains  
the real part of input signal array FFT {X}.  
Im FFT{X} is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains  
the imaginary part of input signal array FFT {X}.  
Notes: The number of elements for the input array must be the power of two. If the size of Re  
FFT{X} is different from the size of Im FFT{X}, the VI uses the smaller number as the size of  
the inverse FFT.  
The operation is performed in place and the input array Re FFT{X } and Im FFT{X} is  
overwritten by Re {X} and Im {X}.  
The largest inverse FFT that can be computed depends upon the amount of memory on your  
DSP board.  
Re {X} is a DSP Handle Cluster that is identical to Re FFT{X }, but with the real part of X already  
stored in the memory buffer on the DSP board.  
Im {X} is a DSP Handle Cluster that is identical to the Im FFT{X} but with the imaginary part of X  
already stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Inverse FHT  
Computes the inverse fast Hartley transform of  
the input sequence FHT {X}. The inverse  
Hartley transform of a function X(f) is defined  
as  
∞
x(t) = ∫ X(f) cas(2πft) df  
-∞  
where cas(x) = cos(x) + sin(x).  
If Y represents the output sequence X, the VI calculates Y through the discrete implementation of the inverse  
Hartley integral:  
n-1  
1
n
2π ik  
( n )  
Yk =  
Xi cas  
for k = 0, 1, 2, … , n-1  
∑
i=0  
where n is the number of elements in X.  
The inverse Hartley transform maps real-valued frequency sequences into real-valued sequences. You can use it  
instead of the inverse Fourier transform to convolve, deconvolve, and correlate signals. Furthermore, you can derive  
the Fourier transform from the Hartley transform.  
See the description of the DSP FHT VI for a comparison of the Fourier and Hartley transforms.  
FHT {X} is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the  
input signal array.  
Notes: The number of elements for the input array must be a power of 2.  
The operation is performed in place and the input array FHT {X} is overwritten by  
the output array X.  
The largest inverse FHT that can be computed depends upon the amount of memory in your  
DSP board.  
X is a DSP Handle Cluster that is identical to FHT {X}, but with the results of inverse FHT {X } already  
stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Kaiser-Bessel Window  
Applies a Kaiser-Bessel window to the  
input sequence X. If Y represents the  
output sequence Kaiser-Bessel{X}, the  
elements of Y are obtained using the  
formula:  
Io β 1. 0 - a 2  
Io  
β
( )  
yi = xi  
for i = 0, 1, 2, … n - 1  
i - k  
a =  
k
n-1  
2
k =  
,
where n is the number of elements in X, and  
I ( ) is the zeroth-order modified Bessel function.  
•
o
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array.  
Note: The operation is performed in place and the input array X is overwritten by the output  
Kaiser-Bessel {X}.  
beta is proportional to the sidelobe attenuation–that is, the larger beta is, the greater the sidelobe  
attenuation is. beta defaults to 0.0.  
Kaiser-Bessel {X} is a DSP Handle Cluster that is identical to X, but with the results of  
Kaiser-Bessel {X} already stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Linear Evaluation  
Performs a linear evaluation of the input array  
th  
X. The i element of the output array Y is  
obtained using the following formula:  
Y(i) = a* X(i) + b for i = 0, 1, 2, …, n-1,  
where n is the number of elements in X.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array X.  
a is the multiplicative constant. a defaults to 1.0.  
b is the additive constant. b defaults to 0.0.  
Y in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will contain the  
results of output array.  
Y out is a DSP Handle Cluster that is identical to Y in, but with the results already stored in the memory  
buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
The operation can be performed in place; that is, the input and output arrays can be the same DSP Handle Cluster.  
DSP Load  
Downloads a library specified by path name to  
the DSP board in slot. path name must contain  
the full path name of a valid COFF file (.out  
file).  
slot is the board ID number. slot defaults to 3.  
path name is the path name of the .outfile.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Log  
Computes the logarithm base 10 of the X input  
array. The ith element of resulting array is  
obtained by using the following formula:  
y(i) = log10 (X(i)) * mult  
for i = 0, 1, 2, …, n-1,  
where n is the number of elements in X.  
This VI is useful for converting values that represent power to decibels. This VI returns the most negative number  
for any input less than or equal to zero.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array.  
mult defaults to 1.0.  
Y in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will contain the  
results of logarithm X.  
Y out is a DSP Handle Cluster that is identical to Y in, but with the results of logarithm X already stored  
in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Max & Min  
Finds the maximum and minimum values in the  
input array, as well as the respective indices of  
the occurrence of the maximum and minimum  
values.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array X.  
max value is the maximum value of the input array.  
max index is the index into the input array where maximum occurred.  
min value is the minimum value of the input array.  
min index is the index into the input array where minimum occurred.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Median Filter  
Applies a median filter of rank to the  
input sequence X. The median filter is a  
nonlinear filter that combines lowpass  
filters characteristics (to remove high-  
frequency noise) and high-frequency  
characteristics (to detect edges).  
If Y represents the output sequence  
Filtered Data, if Ji represents a subset  
of the input sequence X centered about the i element of x:  
th  
Ji = {xi-r, xi-r+1, …, xi-1, xi, xi+1, …, xi+r-1, xi+r},  
and if the indexed elements outside the range of X equal zero, the VI obtains the elements of Y using:  
yi = Median(Ji)  
for i = 0, 1, 2, …, n-1,  
where n is the number of elements in the input sequence X, and  
r is the filter rank.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
data array. The number of elements in X must be greater than the rank:  
n>r≥0.  
If the number of elements in X is less than or equal to rank, the VI returns an error.  
rank must be greater than or equal to zero. If rank is less than zero, the VI returns an error. rank  
defaults to 2.  
Filtered Data in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will  
contain the filtered data output.  
Filtered Data out is a DSP Handle Cluster that is identical to Filtered Data in, but with the filtered data  
already stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
The operation cannot be performed in place; that is, the input X and the output Filtered Data cannot be the same  
DSP Handle Cluster.  
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DSP Multiply  
th  
Multiply array X by array Y. The i element  
of the output array Z is obtained using the  
following formula:  
Z(i) = X(i) * Y(i) for i = 0, 1, 2, …, n-1,  
where n is the smaller number of elements in X  
and Y.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array X.  
Y is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array Y.  
Z in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will contain the  
results of X(i) * Y(i).  
Z out is a DSP Handle Cluster that is identical to Z in, but with the multiplied results already stored in  
the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
The operation can be performed in place; that is, the input and output arrays can be the same DSP Handle Cluster.  
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DSP Parks-McClellan  
Generates a set of linear-phase finite impulse  
response multiband digital filter coefficients  
using the number of taps, sampling  
frequency, filter type, and Band Parameters.  
# of taps is the total number of coefficients in H. A tap corresponds to a multiplication and an addition.  
If there are n taps, every filtered sample requires n multiplications and n additions. # of taps must be  
greater than 0. If # of taps is less than or equal to zero, the VI returns an error. # of taps defaults to 32.  
sampling freq : fs defaults to 1.0.  
Band Parameters is a cluster. Each cluster element contains the necessary information associated with  
each band for the FIR design. Each cluster contains four elements, as shown in the following figure:  
The Band Parameters cluster must contain at least one element, that is, one band.  
amplitude is a DSP Handle Cluster that indicates the memory buffer on the DSP board that  
contains the desired amplitude for each band.  
lower freq is a DSP Handle Cluster that indicates the memory buffer on the DSP board that  
contains the lower frequency bands.  
higher freq is a DSP Handle Cluster that indicates the memory buffer on the DSP board  
that contains the upper frequency bands.  
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weighted ripple is a DSP Handle Cluster that indicates the memory buffer on the DSP  
board that contains the weighting factor for each band.  
For each band, higher freq must be greater than lower freq, and for adjacent bands, lower  
freq in the higher band must be greater than higher freq in the lower band,  
fhi > fli ,  
for i = 0, 1, 2, …, m-1,  
fli+1 > fhi , for i = 0, 1, 2, …, m-2,  
th  
th  
where flirepresents the lower freq in the i band, and fhi represents the higher freq in the i  
band.  
The higher freq in the last band must observe the Nyquist criterion:  
fhm-1 ≤ 0.5f ,  
s
where fs is the sampling frequency.  
If Band Parameters does not contain any elements, or if any of the preceding frequency  
conditions is violated, the VI returns an error.  
filter type has three options:  
0: multiband.  
1: differentiator.  
2: Hilbert.  
filter type defaults to multiband.  
ripple is the optimal ripple the VI computes and is a measure of deviation from the ideal filter  
specifications.  
H in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will contain the  
FIR coefficients.  
H out is a DSP Handle Cluster that is identical to H in, but with the coefficients already stored in the  
memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
Note: The DSP Parks-McClellan VI finds the coefficients using iterative techniques based upon an error criterion.  
Although you specify valid filter parameters, the algorithm may fail to converge.  
The DSP Parks-McClellan VI generates only the filter coefficients. It does not perform the filtering  
function. To filter a sequence X using the set of FIR filter coefficients H, use the DSP Convolution VI with  
X and H as the input sequences.  
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The equi-ripple filters use a similar technique to filter the data.  
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Parameter Discussion  
The weights are usually the same for every band and inversely proportional to frequency f for a differentiate. The  
amplitudes of the bands are usually the same for every band and form a slope for a differentiation. The designed  
filter is unconstrained, that is the frequency response in transitional period specifications is not guaranteed. Adjust  
the parameters if there are discrepancies between specifications and results.  
Generally, when type = multiband and bands ≥ 2, the DSP Parks-McClellan VI designs a multiband filter. When  
filter type = differentiator and bands = 1, the DSP Parks-McClellan VI designs a differentiation. When  
filter type = Hilbert and bands = 1, the DSP Parks-McClellan VI designs a Hilbert transform. The following tables  
contain the brief requirements you must meet when you design different types of filters. For more information,  
please refer to Digital Filter Design by Parks and Burrus, or "A Computer Program for Designing Optimum FIR  
Linear Phase Digital Filters," by McClellan, Parks, and Rabiner.  
When filter type = Multiband:  
Filter Band Type  
# of Bands (n)  
# of taps  
LowPass  
HighPass  
BandPass  
BandStop  
2
2
≥3  
odd/even  
≥3  
odd  
odd/even  
0.0  
odd  
0.0  
fl[0]  
0.0  
0.5fs  
≥0.0  
0.0  
0.5fs  
>0.0  
fh[n-1]  
0.5fs  
0.5fs  
amp[0]  
>0.0  
≥0.0  
amp[n-1]  
0.0(for even taps) >0.0  
≥0.0(for odd taps)  
0.0(for even taps) >0.0  
≥0.0(for odd taps)  
fl[0] represents the first value in the array of Lower Freq.  
fh[n-1] represents the last value in the array of Higher Freq.  
amp[0] represents the first value in the array of Amplitude.  
amp[n-1] represents the last value in the array of Amplitude.  
fs is the sample frequency.  
When filter type = Differentiator or Hilbert:  
Filter Type  
bands(n)  
fl[0]  
Diff(odd)  
Diff(even)  
Hilbert(odd)  
Hilbert(even)  
≥1  
0.0  
0.5fs-∆  
≥1  
0.0  
0.5fs  
≥1  
0.0+∆  
0.5fs-∆  
≥1  
0.0+∆  
0.5fs  
fh[n-1]  
odd or even in the table refers to the value of the # of taps.  
fl[0] represents the first value in the array of Lower Freq.  
fh[n-1] represents the last value in the array of Higher Freq.  
fs is the sample frequency.  
∆ is a small number that specifies the transitional band.  
Although the DSP Parks-McClellan VI is the most flexible way to design a FIR linear phase filter, it has more  
complex parameters and requires some DSP knowledge. You may find it more convenient to use DSP Equi-Ripple  
LowPass, DSP Equi-Ripple HighPass, DSP Equi-Ripple BandPass, and DSP Equi-Ripple BandStop. These  
functions, which provide lowpass, highpass, bandpass and bandstop FIR filters with equal weighting factors in all  
bands, are special cases of the DSP Parks-McClellan VI with simplified parameters.  
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DSP Polar to Rectangular  
Converts a set of polar coordinate points  
(Magnitude, Phase) to a set of rectangular  
th  
coordinate points (X, Y). The i elements  
of the rectangular set is obtained using the  
following formulas:  
X(i) = Magnitude(i) * cos(Phase(i))  
Y(i) = Magnitude(i) * sin(Phase(i))  
Note: The operation is performed in place and the input arrays Magnitude and Phase are overwritten by X and  
Y.  
Magnitude is the DSP Handle Cluster that indicates the memory buffer on the DSP board that  
contains the input signal array Magnitude.  
Phase is the DSP Handle Cluster that indicates the memory buffer on the DSP board that contains  
the input signal array Phase.  
X is the DSP Handle Cluster that is identical to Magnitude but with the caculated rectangular  
coordinate values already stored in the memory buffer on the DSP board.  
Y is the DSP Handle Cluster that is identical to Phase but with the caculated rectangular coordinate  
values already stored in the memory buffer on the DSP board.  
error in(no error) contains the error information from a previous VI. If an error occurs, it is passed  
out error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Polynomial Evaluation  
Performs a polynomial evaluation on the input  
th  
array X. The i element of the output array Y  
is obtained using the following formula:  
k-1  
j
Y(i) = ∑ (Coefficients(j) X(i) )  
*
j=0  
for i = 0, 1, 2, …, n-1,  
where n is the number of elements in X and k is the number of elements in Coefficients.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array X.  
Coefficients is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains  
the coefficients array.  
Y in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will contain the  
results of output array.  
Y out is a DSP Handle Cluster that is identical to Y in, but with the results already stored in the memory  
buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
The operation can be performed in place; that is, the input X and the output Y can be the same DSP Handle Cluster.  
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DSP Power Spectrum  
Computes the Power Spectrum of the  
input sequence X. The Power Spectrum  
Sxx(f) of a function x(t) is defined as  
Sxx(f) = X*(f)X(f) = | X(f) | 2 ,  
*
where X(f) = F{x(t)}, and X (f) is the  
complex conjugate of X(f).  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array.  
Notes: The number of elements for the input array must be a power of two.  
The operation is performed in place and the input array X is overwritten by the output Power  
Spectrum.  
The largest power spectrum that can be computed depends upon the amount of memory on your  
DSP board.  
This VI allocates a temporary workspace on the DSP board equal to the size of the input signal  
array.  
Power Spectrum is a DSP Handle Cluster that is identical to X, but with the results of Power  
Spectrum already stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
DSP Product  
Finds the product of the elements of the input  
array X. The product of the elements is  
obtained using the following formula:  
product = n−1X(i)  
∏
i=0  
where n is the smaller number of elements in X.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array X.  
product is the product of the elements in X.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Pulse Pattern  
Generates an array containing a pulse  
pattern. If Pulse Pattern is represented  
by the sequence X, then the pattern is  
generated according to the following  
formula:  
a if d ≤ i < last  
xi =  
0 elsewhere  
for i = 0, 1, 2, … , n-1 ,  
last = d + w ,  
where a is the amplitude,  
d is the delay,  
w is the width, and  
n is the number of elements in Pulse Pattern.  
amplitude defaults to 1.0.  
delay must be greater than or equal to 0. delay defaults to 0.  
width must be greater than or equal to 0. width defaults to 1.  
Pulse Pattern in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will  
contain the output pulse pattern.  
Pulse Pattern out is a DSP Handle Cluster that is identical to Pulse Pattern in, but with the generated  
pattern already stored in the memory buffer on the DSP board. The largest pulse pattern that can be  
generated depends upon the amount of memory on your DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Ramp Pattern  
Generates an array containing a ramp  
pattern. If the Ramp Pattern is  
represented by the sequence X, then the  
pattern is generated according to the  
formula:  
xi = x0 + i ∆x  
for i = 0, 1, 2, … , n-1 ,  
xn-1 - x0  
where ∆x =  
,
n - 1  
xn-1 is the final,  
x0 is the init, and  
n is the number of elements in Ramp Pattern.  
The Ramp Pattern VI does not impose conditions on the relationship between init and final. The VI can therefore  
generate ramp-up and ramp-down patterns.  
final defaults to 0.0.  
init defaults to 1.0.  
Ramp Pattern in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will  
contain the output ramp pattern.  
Ramp Pattern out is a DSP Handle Cluster that is identical to Ramp Pattern in, but with the generated  
pattern already stored in the memory buffer on the DSP board. The largest ramp pattern that can be  
generated depends upon the amount of memory on your DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Random Pattern  
Generates a uniformly distributed  
pseudorandom pattern whose values  
are in the range [0:1]. The sequence is  
generated using the Very-Long-Cycle  
random number generator algorithm.  
seed < 65536.0. If seed > 0.0, the generated noise will be the same in repeated invocations if the seed  
value does not change. If seed ≤ 0.0, the VI generates a random value to use as the seed, and the noise  
differs in repeated invocations although the value in seed does not change. seed defaults to 0.0.  
Random Pattern in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that  
will contain the output random pattern.  
Random Pattern out is a DSP Handle Cluster that is identical to Random Pattern in, but with the  
generated pattern already stored in the memory buffer on the DSP board. The largest random pattern  
that can be generated depends upon the amount of memory on your DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Rectangular To Polar  
Converts a set of rectangular coordinate  
points (X, Y) to a set of polar coordinate  
th  
points (Magnitude, Phase). The i  
element of the polar coordinate set is  
obtained by using the following fomulas:  
2
2
Magnitude(i) = X(i) +Y(i)  
Phase(i) = arctan(Y(i)/X(i))  
Note: The operation is perfomed in place and the input arrays X and Y are overwritten by Magnitude and Phase.  
X is the DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the  
input signal array X.  
Y is the DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the  
input signal array Y.  
Magnitude is the DSP Handle Cluster that is identical to X but with the caculated polar coordinate  
amplitude values already stored in the memory buffer on the DSP board.  
Phase is the DSP Handle Cluster that is identical to Y but with the caculated polar coordinate phase  
values already stored in the memory buffer on the DSP board.  
error in(no error) contains the error information from a previous VI. If an error occurs, it is passed  
out error out and no other calls are made.  
error out contains the error information for this call.  
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DSP ReFFT  
Computes the Fast Fourier transform of a  
real input sequence X. If Y represents  
the complex output sequence, then:  
Y = F{X}.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array.  
Notes: The number of elements for input X must be the power of two.  
The operation is performed in place and the input array X is overwritten by Re FFT{X}.  
The largest FFT that can be computed depends upon the amount of memory in your DSP board.  
Im FFT{X} in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will  
contain the imaginary part of FFT{X}.  
Re FFT{X} is a DSP Handle Cluster that is identical to X, but with the real part of FFT{X}already  
stored in the memory buffer on the DSP board.  
Im FFT{X} out is a DSP Handle Cluster that is identical to Im FFT{X} in, but with the imaginary part  
of FFT{X} already stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
DSP Reset  
DSP Reset aborts any currently running  
function on the board, stops the library, and  
reloads the DSP Library from the directory  
specified in the WDAQCONF.EXEfile.  
slot is the board ID number. slot defaults to 3.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Reverse  
Reverse the order of the elements of the input  
array X.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array X.  
The operation can only be performed in place; that is, the input X is overwritten by the output Reverse {X}.  
Reverse {X} is a DSP Handle Cluster that is identical to the X, but with the reverse {X} already stored  
in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Sawtooth Pattern  
Generate a sawtooth pattern with  
positive-slope, zero-crossing at  
sample delay. If the sawtooth  
pattern is represented by the  
sequence Y, then the pattern is  
generated according to the  
following formula:  
2a  
T
T
2
k
if 0 ≤ k <  
y =  
i
for i = 0, 1, 2, ..., n - 1  
2a  
T
T
2
(k -T) if ≤ k < T  
n
cycles  
where k = (i - d) modulo T and  
d is the delay, and  
T =  
,
n is the number of elements in the sawtooth pattern.  
amplitude defaults to 1.0.  
delay defaults to 0.  
cycle defaults to 1.0.  
Sawtooth in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will  
contain the output sawtooth pattern.  
Sawtooth out is a DSP Handle Cluster that is identical to Sawtooth in, but with the generated pattern  
already stored in the memory buffer on the DSP board. The largest sawtooth pattern that can be  
generated depends upon the amount of memory on your DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Set  
Set the elements of the input array X to the  
constant value set value. If the output Set {X}  
is represented by the sequence Y, then:  
yi = set value  
for i = 0, 1, 2, …, n-1 ,  
where n is the number of elements in X.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array X. The operation is performed in place; that is, the input X is overwritten by the output  
Set {X}.  
set value defaults to 0.0.  
Set {X} is a DSP Handle Cluster that is identical to X, but with the set {X} already stored in the memory  
buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
DSP Shift  
Shifts the elements in the input array X,  
replacing the new values with zeros. The  
number of shifts selected can be in the  
positive (right) or negative (left) direction.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array X.  
# of shifts defaults to 0.  
Shifted {X} in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will  
contain the output array of shifted {X}.  
Shifted {X} out is a DSP Handle Cluster that is identical to Shifted {X} in, but with the  
shifted {X} already stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
The operation can be performed in place; that is, the input and output arrays can be the same DSP Handle Cluster.  
Parameter Discussion  
Shifting can be performed right or left by setting # of shifts to a positive or negative value, respectively. If # of  
shifts is greater than n, ( n is the number of elements of input array X ), the outputs are all zero.  
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DSP Sinc Pattern  
Generates an array containing a sinc  
pattern. If the Sinc Pattern is represented  
by the sequence Y, then the pattern is  
generated according to the following  
formula:  
yi = a sinc(i∆ t - d) ,  
for i = 0, 1, 2, …, n-1 ,  
sin(πx)  
where sinc(x) =  
,
πx  
a is the amplitude,  
∆t is the sampling interval delta t,  
d is the delay, and  
n is the number of elements in Sinc Pattern.  
The main lobe of the sinc function, sinc(x), is the part of the sinc curve bounded by the region -1 ≤ x ≤ 1.  
When |x| = 1, the sinc(x) = 0.0, and the peak value of the sinc function occurs when x = 0. You can show using  
l'Hôpital's Rule that sinc(0) = 1 and that it is also its peak value. Thus, the main lobe is the region of the sinc curve  
encompassed by the first set of zeros to the left and the right of its peak value.  
amplitude defaults to 1.0.  
delay shifts the peak value within the Sinc Pattern as the VI generates the pattern. This condition is  
determined from the preceding formula and occurs when i∆t = d . delay defaults to 0.0.  
delta t is the sampling interval. It is a floating-point number inversely proportional to the width of the  
main sinc lobe. That is, the smaller the sampling interval, the wider the main lobe, and the larger the  
sampling interval, the smaller the main lobe. Notice that when delta t is 1 and d is an integer value, the  
VI sets Sinc Pattern to zero except at the point where i = d, at which point the value is equal to  
amplitude. The recommended range of values for the sampling interval is 0 < delta t ≤ 1 . delta t must  
be greater than 0.0. If delta t is less than or equal to zero, the VI returns an error. delta t defaults to 1.0.  
Sinc Pattern in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will  
contain the output sinc pattern.  
Sinc Pattern out is a DSP Handle Cluster that is identical to the Sinc Pattern in, but with the generated  
pattern already stored in the memory buffer on the DSP board. The largest sinc pattern that can be  
generated depends upon the amount of memory on your DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Sine Pattern  
Generates an array containing a sinusoidal  
pattern. If the Sine Pattern is represented  
by the sequence Y, the pattern is  
generated according to the following  
formula:  
yi = a sin(xi) ,  
for i = 0, 1, 2, …, n-1 ,  
2πi k  
n
π øo  
180  
where xi =  
+
,
a is the amplitude,  
k is the number of cycles in the pattern,  
øo is the initial phase in degrees, and  
n is the number of elements in Sine Pattern.  
amplitude defaults to 1.0.  
phase defaults to 0.0.  
Note: phase must be in degrees rather than radians. If phase is in radians, make sure you convert it to  
degrees, as shown in the following figure, before using the Sine Pattern VI.  
cycles defaults to 1.0.  
Note: Because cycles is a floating-point number, fractional cycles are possible for the Sine Pattern.  
Furthermore, setting cycles to a negative number does not generate an error condition because it  
is mathematically correct and useful to consider negative frequencies in Fourier and spectral  
analysis.  
Sine Pattern in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will  
contain the output sine pattern.  
Sine Pattern out is a DSP Handle Cluster that is identical to Sine Pattern in, but with the generated  
pattern already stored in the memory buffer on the DSP board. The largest sine pattern that can be  
generated depends upon the amount of memory on your DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Square Pattern  
Generates an array containing a square  
pattern. If the Square Pattern is  
represented by the sequence X, then  
the pattern is generated according to  
the following formula:  
i
a
if 0 ≤ remainder  
< 0.01 dT  
(T)  
xi =  
for i = 0, 1, …, n-1 ,  
0.0 elsewhere  
n
where T =  
is the time period of one cycle of the Square Pattern,  
cycles  
a is the amplitude,  
d is the duty cycle in percent, and  
n is the number of elements in Square Pattern.  
amplitude defaults to 1.0.  
duty cycle must be greater than or equal to 0 and less than or equal to 100. If duty cycle is less than  
zero or greater than 100, the VI returns an error. duty cycle defaults to 50.0.  
Note: duty cycle must be a percentage. Make sure you convert the fractions of a cycle into  
percentages, as shown below, before using the DSP Square Pattern VI in a block diagram.  
Special Cases: Two special cases can occur when the duty cycle assumes its extreme values of 0 and  
100. The VI sets Square Pattern to zero:  
duty cycle = 0 or 100  
⇒
X = 0.  
cycles must be greater than 0. If cycles is less than or equal to zero, the VI returns an error. cycles  
defaults to 1.0.  
Note: Because cycles is a floating-point number, fractional cycles of the Square Pattern are  
permitted.  
Square Pattern in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will  
contain the output square pattern.  
Square Pattern out is a DSP Handle Cluster that is identical to Square Pattern in, but with the  
generated pattern already stored in the memory buffer on the DSP board. The largest square pattern that  
can be generated depends upon the amount of memory on your DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Square Root  
Find a square root estimate of the absolute value  
th  
of each element of the input array X . The i  
element of the output array Y is obtained using  
the following formula:  
Y(i) = |X(i)|  
for i = 0, 1, 2, …, n-1 ,  
where n is the number of elements in X.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array X.  
Y in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will contain the  
square root results of X(i).  
Y out is a DSP Handle Cluster that is identical to Y in, but with the square root results already stored in  
the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
The operation can be performed in place; that is, the input and output arrays can be the same DSP Handle Cluster.  
If the input value is negative, it calculates the square root of the absolute value of that number.  
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DSP Sort  
Sort the input array X in ascending or  
descending order.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array X.  
direction is the direction to sort:  
0: ascending.  
1: descending.  
direction defaults to ascending.  
Sorted {X} in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will  
contain the output array of sorted {X}.  
Sorted {X} out is a DSP Handle Cluster that is identical to Sorted {X} in, but with the sorted {X}  
already stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
The operation can be performed in place; that is, the input and output arrays can be the same DSP Handle Cluster.  
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DSP Start  
Enables the DSP board to run. Use DSP Start  
with the DSP Load and DSP Reset VIs after  
downloading a custom application.  
slot is the board ID number. slot defaults to 3.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
DSP Subset  
Extracts a subset of array X of length beginning  
at index and stores it in array Y.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array X.  
index defaults to 0.  
length is the length of the output subset. length defaults to 1.  
Y in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will contain the  
subset output array.  
Y out is a DSP Handle Cluster that is identical to Y in, but with the subset array already stored in the  
memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
This VI is particularly useful when performing onboard processing with large arrays, with index different from zero,  
or Y in a memory space different from X. If index is less than zero, then the first element of the subset is the first  
element of the input array.  
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DSP Subtract  
th  
Subtract array Y from array X. The i element  
of the output array Z is obtained using the  
following formula:  
Z(i) = X(i) -Y(i). for i = 0, 1, 2, …, n-1 ,  
where n is the smaller number of elements in X  
and Y.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array X.  
Y is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array Y.  
Z in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will contain the  
results of X(i) - Y(i).  
Z out is a DSP Handle Cluster that is identical to Z in, but with the subtracted results already stored in  
the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
The operation can be performed in place; that is, the input and output arrays can be the same DSP Handle Cluster.  
DSP Sum  
Find the sum of the elements of the input array  
X. The sum of the elements is obtained using  
the following formula:  
n-1  
sum =  
X(i)  
∑
i=0  
where n is the number of elements in X.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array X.  
sum is the sum of the elements in X.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP TimeOut  
Selects the timeout limit in seconds to wait  
for a function on DSP board to complete  
execution.  
The default timeout setting at startup and  
after a DSP Reset call is 10 s.  
All subsequent calls from the VI to the  
onboard functions on the specified board return timeout errors if function execution on the board calling the VI is  
not completed in the timeout limit.  
slot is the board ID number. slot defaults to 3.  
timeout is the timeout in seconds. timeout defaults to 10.0 s.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Triangle Pattern  
Generates an array containing a  
triangle pattern. If the Triangle  
Pattern is represented by the  
sequence Y, the pattern is generated  
according to the following formula:  
yi = a tri (xi) ,  
for i = 0, 1, 2, …, n-1 ,  
where  
i∆t - d  
w
xi =  
, and  
1 - | x |  
0
if | x | ≤ 1  
tri(x) =  
elsewhere  
a is the amplitude,  
d is the delay,  
w is the width, and  
n is the number of elements in Triangle Pattern.  
amplitude is the value of the waveform at the peak. amplitude defaults to 1.0.  
delay is the distance in seconds between the beginning of the pattern and the peak. delay shifts the peak  
value within Triangle Pattern. delay defaults to 0.0.  
delta t is the duration of the pattern in seconds, or the sampling interval, and must be greater than 0.0 to  
avoid undefined arguments. If delta t is less than or equal to zero, the VI returns an error. delta t  
defaults to 1.0.  
width is the distance in seconds between the peak and end of the pattern. In other words, width sets the  
width from the peak value to the first zero value in the pattern. Thus the actual duration of the pattern is  
2width (twice the value of width). width must be greater than 0.0 to avoid undefined arguments. If  
width is less than or equal to zero, the VI returns an error. width defaults to 1.0.  
Triangle Pattern in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that  
will contain the output triangular pattern.  
Triangle Pattern out is a DSP Handle Cluster that is identical to Triangle Pattern in, but with the  
generated pattern already stored in the memory buffer on the DSP board. The largest triangle pattern  
that can be generated depends upon the amount of memory on your DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
You use this VI to create patterns based on an isosceles triangle. The following figure shows how the VI parameters  
relate to the generated pattern.  
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Amplitude  
0
0
Delay (s)  
Width (s)  
delta t (s)  
The following figure illustrates how the pattern can vary with different values for the parameters.  
Delay = 0 Delay = delta t  
0
0
Width (s)  
delta t (s)  
delta t (s)  
Notice that when the Delay is 0, the signal is a ramp with a slope of -Amplitude/Width, and when Delay equals  
delta t, the signal is a ramp with a slope of Amplitude/Width. Remember that the Width parameter is actually the  
width of the ramp rather than the width of the triangle. delta t is the duration of the pattern in seconds. In the  
previous and following illustrations, the box shows the pattern limits.  
Delay = Width = 0.5 delta t  
Delay + Width = delta t  
Delay(s)  
delta t (s)  
Width (s)  
Delay  
delta t (s)  
Width (s)  
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DSP Triangular Train  
Generates a train of triangular  
pattern crossing value zero at delay  
with positive slope. If the triangular  
train is represented by the sequence  
Y, the pattern is generated according  
to the following formula:  
4a  
T
T
4
k
if 0 ≤ k ≤  
- 4a  
T
T
T
4
3T  
4
k-  
if ≤ k ≤  
y =  
i
for i = 0, 1, 2, ..., n-1  
( )  
2
4a  
3T  
4
(k- T)  
if  
≤ k < T  
T
where k = (i - d) modulo T,  
n
T =  
,
cycles  
n is the number of elements in the triangular train, and  
d is the delay.  
amplitude defaults to 1.0.  
delay defaults to 0.  
cycle defaults to 1.0.  
Triangular Train in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that  
will contain the output triangular train.  
Triangular Train out is a DSP Handle Cluster that is identical to Triangular Train in, but with the  
generated pattern already stored in the memory buffer on the DSP board. The largest triangular train  
that can be generated depends upon the amount of memory on your DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Triangular Window  
Applies a triangular window to the input  
sequence X. If Y represents the output  
sequence Triangle{X}, the elements of Y are  
obtained from the formula:  
yi = xi tri(w)  
for i = 0, 1, 2, …, n-1 ,  
2i-n  
w =  
,
n
where tri(w) = 1 - |w|, and  
n is the number of elements in X.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array.  
Note: The operation is performed in place and the input array X is overwritten by the output Triangle  
{X}.  
Triangle {X} is a DSP Handle Cluster that is identical to X, but with the results of Triangle {X} already  
stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Uniform White Noise  
Generates a uniformly distributed  
pseudorandom pattern whose values are in  
the range [-a:a], where a is the absolute  
value of amplitude. The pseudorandom  
sequence is generated using a modified  
version of the Very-Long-Cycle random  
number generator algorithm.  
amplitude defaults to 1.0.  
seed < 65536.0. If seed > 0.0, the generated noise will be the same in repeated invocations if the seed  
value does not change. If seed ≤ 0.0, the VI generates a random value to use as the seed, and the noise  
differs in repeated invocations although the value in seed does not change. seed defaults to 0.0.  
White Noise in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will  
contain the output white noise.  
White Noise out is a DSP Handle Cluster that is identical to White Noise in, but with the generated  
pattern already stored in the memory buffer on the DSP board. The largest white noise signal that can be  
generated depends upon the amount of memory on your DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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DSP Unwrap Phase  
Unwraps the Phase array by eliminating  
discontinuities whose absolute values exceed π.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array.  
Y in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will contain the  
results of the integration of X.  
Y out is a DSP Handle Cluster that is identical to Y in, but with the unwrapped output array already  
stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
Both the input array and the output array are in radians. The operation can be performed in place; that is, the input  
X and the output Y can be the same DSP Handle Cluster.  
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DSP Zero Padder  
Pads the input array with zero from  
starting index to the end of the input array.  
This VI is useful when the size of the  
acquired data buffers is not a power of two  
and you want to take advantage of fast  
processing algorithms in the analysis VIs.  
These algorithms include Fourier  
transforms, power spectrum, and fast Hartley transforms, which are extremely efficient for buffer sizes that are a  
power of two.  
X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input  
signal array.  
Note: The operation is performed in place and the input array X is overwritten by the output Zero  
Padded {X}.  
starting index is the index from which the input array is padded with zero. starting index defaults to 0.  
Zero Padded {X} is a DSP Handle Cluster that is identical to {X}, but with the zero-padded array  
already stored in the memory buffer on the DSP board.  
error in (no error) contains the error information from a previous VI. If an error occurs, it is passed out  
error out and no other calls are made.  
error out contains the error information for this call.  
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Chapter 1  
Introduction to the NI-DSP Interface Utilities  
This chapter contains an overview of the NI-DSP Interface Utilities, installation instructions, and explains how to  
use the NI-DSP Interface Utilities. You should familiarize yourself with the material in this chapter before  
beginning subsequent chapters in this part.  
The National Instruments AT-DSP2200, a high-performance digital signal processing (DSP) plug-in board for the  
PC, is based on the AT&T WE DSP32C 32-bit, floating-point, digital signal processor. With the NI-DSP  
Interface Utilities, you can customize the DSP Library that resides on the board by adding or deleting functions to  
and from the common object file format (COFF) file that constitutes the onboard-resident software. This COFF  
file is made of the Kernel, memory management routines, execution control routines, data communication  
routines, interrupt handling routines for data acquisition, and a set of more than 60 analysis functions. Throughout  
the chapters in this part, the COFF file is referred to as the DSP Library. By customizing the DSP Library, you  
can change the number of analysis functions that are included. The other parts of the DSP Library always remain  
unchanged.  
Note: To customize the DSP Library that resides on the board, you need to have the Developer ToolKit,  
available through National Instruments, which contains an AT&T C compiler, assembler, linker, and  
documentation.  
Overview of the NI-DSP Interface Utilities  
The NI-DSP Interface Utilities are on the NI-DSP for LabVIEW for Windows distribution disks.  
Unless otherwise stated, all references to directories in this part of the manual are to subdirectories under the path  
you specified during installation of the NI-DSP Interface Utilities. If you chose the path D:\DEVEL, then the  
installer will create the directory DEVEL and copy all files and directories to it. Figure 1-1 shows directory  
structure created by SETUP.  
D:\DEVEL  
Dispatch Examples  
Lib  
Figure 1-1. NI-DSP for DOS Directory Structure  
The Dispatch directory contains the utilities necessary for creating a custom DSP Library dispatcher. The  
Dispatch directory contains the Dispatch application and the files NIDSP.fnc, dispatch.s., and  
NIESSEN.fnc.  
Dispatch is a PC application that uses the files NIDSP.fnc and NIESSEN.fnc and generates the  
WE DSP32C assembly code needed to properly dispatch to a custom DSP Library based on the grouped function  
names.  
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Chapter 1  
The Examples directory contains the files used in Part 4, Chapter 2, Getting Started with the NI-DSP Interface  
Utilities, to build a custom DSP Library.  
The LIB directory contains LIBLVDSP.a, the archived library of object modules containing all of the analysis  
functions and Kernel routines used in building the downloadable DSP Library files, as well as the two DSP  
Library files LV2200S.out and LV2200.out.  
Installing the NI-DSP Interface Utilities  
For instructions on installing the NI-DSP Interface Utilities, refer to Part 1, Getting Started with NI-DSP, under  
the section titled Installing NI-DSP for LabVIEW for Windows.  
For instructions on installing the AT&T WE DSP32C software, refer to the WE DSP32C Support Software Library  
User Manual and other related documentation.  
Using the NI-DSP Interface Utilities  
Use the NI-DSP Interface Utilities to customize the DSP Library and execute your own functions on the DSP board.  
Figure 1-2 shows a diagram of the interface layers used to access functions in your custom library.  
LabVIEW VI  
Call to a CIN  
Driver Software  
(DSP.DLL)  
PC Bus  
+
AT-DSP2200  
KERNEL  
Dispatcher  
Memory  
Manager  
Onboard  
Library  
+
Figure 1-2. Interface Layers to Onboard Functions  
When your library is downloaded and a LabVIEW interface to your function has been created, you can execute a  
function in your onboard custom library by making a call to the interface function in your program from LabVIEW.  
This call passes control to the interface software which calls the NI-DSP driver. The NI-DSP driver communicates  
with the DSP Library to pass parameters, indicates which onboard function to execute using the dispatcher, and  
returns results to LabVIEW.  
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Getting Started with the NI-DSP Interface  
Utilities  
This chapter contains a step-by-step example for building a custom DSP Library, creating a LabVIEW interface to a  
custom function, and executing the custom function from the LabVIEW environment. The chapter demonstrates this  
concept with an example of how to add a custom function. The custom function finds the maximum and minimum  
values in the input array, as well as the respective indices of the occurrence of the maximum and minimum value.  
This example custom function also returns an output array with the input array sorted.  
Creating Your Custom NI-DSP Library  
To build your own custom library, follow these steps:  
1. Create your source code of C functions (or assembly functions).  
2. Compile and/or assemble source code.  
3. Add your object filenames to a linker file (ifile).  
4. Add your new function names to a library function list file.  
5. Run the Dispatchapplication to generate an assembly dispatch file.  
6. Compile, assemble, and link your custom library.  
These steps are detailed in the following pages.  
Note: You can use the source files included in the Examplesdirectory instead of creating the files in this  
example.  
1. Create Your Source Code of C Functions  
The first step in building a custom DSP Library is to create your WE DSP32C C-callable custom function(s). The  
gmaxmin.cexample file in your examplesdirectory contains the source code.  
GMaxMin.c Example:  
/* DSP_GMaxMin(z,y,max,min,n,imax,imin)  
* This function returns the maximum and minimum of array z, as well as the  
* respective indices of the occurrence of the maximum and minimum. The output  
* array y holds the input array sorted.  
*/  
#include "atdsp.h"  
short DSP_GMaxMin(z,y,max,min,n,imax,imin)  
register float *z,*max,*min;  
float *y;  
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long *n,*imin,*imax;  
{
long i,j;  
float *x, small;  
float localmin ,localmax;  
if ((*n)<= 0) return(0);  
x = z;  
localmin = *x;  
localmax = localmin;  
*imax = 0;  
*imin = 0;  
for (i=0;i< *n;i++,*x++) {  
if (localmax < *x) {  
localmax = *x;  
*imax = i;  
}
if (localmin > *x) {  
localmin = *x;  
*imin = i;  
}
}
*min = localmin;  
*max = localmax;  
for(i=0; i< *n; i++) y[i] = z[i];  
for(i=0; i< *n; i++){  
for(j=i+1; j< *n; j++)  
if(y[i] > y[j]) {  
small = y[j];  
y[j] = y[i];  
y[i] = small;  
}
}
return(noError);  
}
Note: The file ATDSP.his the header file containing all of the error codes used by the DSP Library. You can  
find it in the LIBdirectory. To efficiently and correctly compile WE DSP32C code that uses error codes  
defined in ATDSP.h, you may want to copy this header file to the Includedirectory of your WE  
DSP32C tools. Otherwise, you should specify the correct path of ATDSP.hin your program.  
Guidelines for the Custom Functions  
When adding functions to build your custom DSP Library, follow these guidelines:  
•
Pass all parameters by address–All input, output, and input/output parameters, whether arrays or scalars, must  
be passed by address (pointer). For instance, in the example gmaxmin.c, although the length n of an input  
array is only an input scalar, it is passed by address.  
•
You must pass parameters in a certain order–Pass all pointers to arrays, then pass all of the pointers to 32-bit  
floating-point scalars, and then pass all of the pointers to 32-bit long integer scalars. In gmaxmin.c, the  
parameters are passed in the following order–z (input array), y (output array), max (output floating-point  
scalar), min (output floating-point scalar), n (input integer scalar), imax (output integer scalar), and imin  
(output integer scalar).  
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•
Parameters must be 32-bit floating-point, 32-bit integer scalars, or pointers to arrays of data (any type)–  
Supported parameter types are 32-bit floating-point scalars and multidimensional arrays, and 32-bit integer  
scalars and multidimensional arrays.  
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•
•
Return a 16-bit short integer error code–Every function should return an integer error code. A list of error codes  
that the existing DSP Library returns is given in Appendix A, Error Codes. If any of these error codes are used,  
ATDSP.hshould be included at the beginning of your source code. A function that completes with no error  
should return noErroror zero.  
Use the memory management routines–Perform any dynamic onboard memory allocation using the functions  
Alloc_Memand Free_Mem, described in the next section.  
DSP Board Memory Management  
To write your own customized DSP routines that become integrated with the DSP Library, you need some lower  
level memory management routines. Two onboard calls are included with the DSP Library to dynamically allocate  
and deallocate onboard memory–Alloc_Memand Free_Mem. Use these functions instead of the standard C  
routines mallocand free.  
Call the function Alloc_Memwhenever your routines require memory space. Alloc_Memattempts to allocate  
memory of the requested size (in bytes) in any available memory bank. If the requested buffer size (in bytes) is not a  
multiple of four, the allocation routines ensure alignment to the nearest radix 4 boundary >= NumBytes. This is to  
guarantee memory alignment on 4-byte addresses. For example, if you request the allocation of a buffer of size  
1,021, 1,022, 1,023 or 1,024 bytes, then the allocation routines allocate 1,024 bytes in all four cases. The allocation  
routines first attempt to allocate the buffer in on-chip memory (all DSP boards have 4 kilobytes of on-chip memory).  
If the routine fails, the allocation routine tries to allocate the buffer in onboard memory (DSP boards have between  
256 kilobytes and 1.5 megabytes of onboard memory). The function and input parameters for Alloc_Memare  
defined as follows:  
void * Alloc_Mem(size)  
long  
size;  
where sizeis the requested block size in bytes.  
Alloc_Memreturns a pointer to the allocated buffer or returns NULLif the allocation failed.  
Call the function Free_Memwhen you deallocate memory buffers. Use this function instead of the standard C  
function free. The function and input parameters for Free_Mem are defined as follows:  
short  
long  
Free_Mem(ptr)  
ptr;  
where ptris the address of the buffer to be deallocated.  
Free_Memdeallocates the buffer pointed to by ptrif that buffer was allocated previously using Alloc_Mem.  
Free_Memreturns NULLif deallocation succeeded and returns an error code if deallocation did not succeed.  
Each of the NI-DSP Analysis VIs call a function that is part of the DSP Library that resides on the board. Your own  
custom functions can call any of the DSP Library functions included in the NIDSP.fncfile described later in this  
chapter. The DSP functions that you can call from your own functions are prototyped in Part 4, Chapter 3, DSP  
Board Function Overview.  
Note for Assembly Language Programmers: If you are using WE DSP32C assembly language, each function  
must accept and return C-style parameters and preserve all  
registers used in the WE DSP32C environment. For example, the  
function parameters are pushed onto the stack from right to left and  
the return value is placed in Register r1. Refer to the WE DSP32C  
C Language Compiler Library Reference Manual for details.  
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2. Compile and/or Assemble Source Code  
Compile all new C source files and assemble all new assembly source files using the WE DSP32C C compiler and  
assembler. Remember to use only floatand longdata types for scalars. If you use any of the error codes from  
Appendix A, Error Codes, include ATDSP.hat the beginning of your source code. A function that completes with  
no error should return noErroror zero. The ATDSP.hfile is in the Libdirectory. After you have installed the  
WE DSP32C tools, you may want to copy ATDSP.hto the Includedirectory in the root directory for those tools.  
In this example, use d3cc -c gmaxmin.cto generate WE DSP32C object code.  
3. Add Your Object Filenames to a Linker File (ifile)  
The next step is to modify the file NIDSPLNKto add the names of your custom object files to the list of modules to  
be linked into your custom DSP Library. NIDSPLNKis a source file containing link editor directives for the WE  
DSP32C tools. This modification is illustrated in Figure 2-1.  
essent.o  
stackbld.o  
/*** Add all your file names after this comment line ***/  
gmaxmin.o  
/*** Add all your file names above this comment line ***/  
-lLVDSP  
Figure 2-1. Linker File NIDSPLNK  
Copy the NIDSPLNKfile from the LIBdirectory to your working directory and then modify the copy. This ensures  
that you maintain the original ifile. Also, you need to copy the files essent.o, dsp_glob.o, and  
stackbld.s, from the LIBdirectory to your working directory.  
Note: Add your function(s) name(s) to this file between the comments instructing you to do so. Do not modify  
this file in any other way.  
4. Add Your New Function Names to a Library Function List File  
Copy the files NIDSP.fncand NIESSEN.fncfrom the Dispatchdirectory to your working directory.  
In Figure 2-2, the file NIDSP.fncshows the addition of the function DSP_GMaxMinto the library function list.  
This is done by editing the file NIDSP.fncin the current directory. Add this function to a new group, My  
Functions, at the end of this file.  
** My Functions  
DSP_GMaxMin  
Figure 2-2. Library Function List File NIDSP.fnc  
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Notice that functions accepted by the Dispatchapplication should have acceptable C syntax, that is, names may  
contain letters, numbers, and the underscore character but must start with a letter or underscore. A function name  
can contain up to 31 characters. You must divide your functions into groups with a maximum of 64 (40 hex)  
functions per group. The Dispatchapplication returns an error message if function names are not acceptable or if  
you have more than 64 functions per group. You may have up to 24 groups of 64 functions each. The Dispatch  
application assigns a unique ID number to each function depending on how the functions are grouped. Groups start  
at zero and are consecutive (Group 0, 1, 2, ...). The ID number of the first function of a group is the group number  
multiplied by 64. The function IDs are then consecutive within that group. The function ID, therefore, has group  
information as well as index information for functions within each group. This information is necessary for the  
dispatcher to execute a particular function efficiently based on the function ID. The first group of functions are the  
Essential Functions group. The Essential Functions are always linked into the DSP Library. These functions are  
specified in NIESSEN.fnc. Do not modify this file. In the library function list file, NIDSP.fnc, group  
beginnings are marked by two asterisks (** ) followed by a group name. Figure 2-3 shows a typical section of  
NIDSP.fnc.  
** group name  
function name  
function name  
:
:
:
** group name  
function name  
function name  
:
:
:
Figure 2-3. Typical Section of NIDSP.fnc  
Customizing the DSP Library by Deleting Functions  
Another way to customize the DSP Library is to delete functions from NIDSP.fnc. This decreases the size of the  
DSP Library because the object code for those deleted functions are not included. To customize the DSP Library by  
deleting functions, follow the instructions in this chapter, but delete functions rather than add functions. Follow  
these guidelines when deleting functions from the DSP Library:  
•
When modifying the NIDSP.fnc, replace the name of each function you want to delete with the function name  
DSP_NOP. This replacement ensures that the remaining functions in the library are addressable by the  
dispatcher using the same function ID. The Interface Library DSP.DLLis built using the organization of the  
original library function list file, and thus function IDs are hard coded into the Interface Library. If you  
reorganize the original functions and groups without replacing the function name with DSP_NOP, the interface  
to the function calls a different DSP Library function, which causes the DSP Library to fail. For example, if  
you had a function group with 10 functions and you wanted to delete the first and third functions of that group,  
if you replace their names with DSP_NOP, you can ensure that all of the other functions in the group maintain  
the same function ID. This ensures that the interface code for those functions remain valid. If you do not  
follow these guidelines, functions become disorganized, you could call the wrong function, and an unexpected  
error could happen.  
•
Never delete any of the function group names that form the original DSP Library that you received with the  
NI-DSP software package. The function group names ensure that the remaining functions in the DSP Library  
have the same function IDs. If you want to delete all functions of a group, replace each function name of that  
group in the NIDSP.fncwith DSP_NOP.  
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5. Run the Build Dispatch Application to Generate an Assembly Dispatch File  
The next step is to generate an assembly dispatch file. In the current directory, run dispatch.exe. You can find  
the executable file under the dispatchdirectory. The Dispatchapplication automatically generates the WE  
DSP32C assembly code file dispatch.sand a header file dspfncs.hin your current directory.  
The dspfncs.hfile has define statements assigning function codes for all the functions in the library. Each  
function code is used by the LabVIEW interface when calling the DSP Library. The onboard Kernel uses these  
function codes (passed to it by the interface code) to execute the proper functions. Look at the file dspfncs.hto  
see the resulting function IDs assigned to your custom functions. The function codes for DSP_GMaxMinis 448.  
Remember this code. You will use the code later to build your LabVIEW interface VI. Figure 2-4 shows a section  
of dspfncs.hcorresponding to the section given from NIDSP.fnc. Notice that in this example, Signalswas  
the seventh group (Group 6) listed in NIDSP.fncand hence the function IDs.  
/** Signals  
**/  
#define DSP_Sine_NUM 384  
#define DSP_Square_NUM 385  
#define DSP_Sinc_NUM 386  
:
:
:
:
Figure 2-4. Signals Group Section in dspfncs.h  
The file dispatch.sis an assembly file that the Kernel uses to execute the proper function. This file has  
information about the number of groups and the number of functions per group that are linked into the software that  
resides on the board. The Dispatchapplication uses the files NIDSP.fncand NIESSEN.fncto create  
dispatch.s. Figure 2-5 shows a section of dispatch.scorresponding to the section given from  
NIDSP.fnc. Notice that in this example, Signalswas the seventh group (Group 6) listed in NIDSP.fnc.  
Group zero is the group of Essential Functions.  
/** Signals  
**/  
call DSP_Sine(r18)  
nop  
goto FNC_CALL_END  
nop  
call DSP_Square(r18)  
nop  
goto FNC_CALL_END  
nop  
call DSP_Sinc(r18)  
nop  
goto FNC_CALL_END  
nop:  
:
:
:
Figure 2-5. Signals Group Section in dispatch.s  
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6. Compile, Assemble, and Link Your Custom Library  
The last step in building a custom DSP Library is to compile, assemble, and link your custom library using the WE  
DSP32C tools. You must have installed those tools as described in the WE DSP32C Support Software Library User  
Manual. You must copy the file LIBLVDSP.afrom the LIBdirectory in the stand-alone root directory to the LIB  
directory of the WE DSP32C tools as set by the environment variable recommended in the WE DSP32C Support  
Software Library User Manual. Table 2-1 lists the files you need to build the custom NI-DSP example.  
Table 2-1. Files Required to Build the Custom DSP Library Example  
File  
Description  
makelib.bat  
gmaxmin.c  
dspfncs.h  
dispatch.s  
NIDSPLNK  
Batch file to build the custom library  
C source file  
C include file generated by Dispatch  
Assembly file generated by Dispatch  
Modified linker command file  
Archived library of object modules for the DSP Library functions  
for LabVIEW  
LIBLVDSP.a*  
libc32c.a*  
libap32c.a*  
libm32c.a*  
AT&T C library  
AT&T Application library  
AT&T Math library found in the LIBdirectory in the path set by  
the environment variable  
*
All these archives must be in the LIBdirectory in your WE DSP32C tools directory.  
Copy the file makelib.batfrom the LIBdirectory. This is a batch file that rebuilds the DSP Library file to  
reflect the customization and changes needed. You must enter in the memory map file names to this .batfile to  
use in linking the DSP Library file, as well as the name of the output file for the DSP Library file. The two memory  
map files used for linking the DSP Library files that come with NI-DSP, dsp64.mapand dsp.map, are located in  
the LIBdirectory. Copy the memory map file that you will use to your current directory. The memory map files  
are used when linking the DSP Library files LV2200S.outand LV2200.out, respectively. You can rename  
these files and move them to other directories. If you want the driver to load this new DSP Library file, make sure  
you run WDAQCONFas described in the section titled Board Configuration in Part 1, Getting Started with NI-DSP.  
You should use one of the memory map files, dsp64.mapor dsp.map, as input to makelib.bat. If the size of  
your library cannot be linked using the section sizes specified in these memory map files, you must edit these files  
accordingly. Refer to the WE DSP32C Support Software Library User Manual for more information.  
To begin rebuilding the customized DSP Library, type the following command:  
makelib memmap libfile  
where  
memmap  
is the name of the memory map file used  
libfile is the name of the desired DSP Library file name  
For example,  
makelib dsp64 LV2200S  
Do not use the extension names .mapand .outfor the fields memmapand libfile.  
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The makelib.batbatch file performs the following:  
1. makelib.batassembles the file stackbld.sin the current directory using the AT&T d3as.exe  
assembler. You need to assemble this file because it includes the file stackbld.s, created by the  
Dispatchprogram, and contains the assembly code that determines which function the DSP board executes.  
The file dispatch.sreflects the organization and content of the DSP Library file as is reflected by the library  
function list file, NIDSP.fnc, in the current directory.  
2. makelib.batrebuilds the DSP Library file with name libfile.out(the name you decided to give to the  
new DSP Library file). This new DSP Library file always has the Kernel, memory management routines,  
execution control routines, data communication routines, interrupt handling routines for data acquisition, and  
the functions listed in the library function list file NIDSP.fnc.  
3. makelib.batlists all undefined symbols from the DSP Library file. These symbols could be undefined  
because you did not link all the object modules.  
Any other error messages that are encountered are WE DSP32C error messages. Refer to the WE DSP32C Support  
Software Library User Manual for information.  
At this point, the WE DSP32C tools have generated a custom DSP Library file.  
Creating Your LabVIEW Interface  
Now that you have added a function to the DSP Library, you need to be able to call this function from LabVIEW  
using a VI. The NI-DSP Analysis VIs contains a VI called Custom VI in the Utility folder. You can use the Custom  
VI to call any function on the DSP board that follows the guidelines listed in the Guidelines for the Custom  
Functions section earlier in this chapter.  
To create your LabVIEW interface, follow these steps:  
1. Bundle all the input parameters to arrays.  
2. Call the Custom VI.  
3. Index the output arrays to get the results.  
1. Bundle All of the Input Parameters to Arrays  
Use the Custom VI in the Utility folder of the DSP2200 folder as the interface for calling custom functions on the  
DSP board from LabVIEW. You can use three types of data for input/output parameters in the Custom VI. The data  
types correspond to the different types of parameters that you can use in your custom functions on the DSP board.  
Custom functions have three groups of parameters–pointers to arrays of data (any type; 32-bit floating point, 32-bit  
integer, and 16-bit integer), pointers to 32-bit floating-point scalars, or pointers to 32-bit integer scalars. All of the  
parameters in a group must be the same type. You must arrange the custom function parameters so that the group of  
all array pointers (if the function has any) are first, followed by the group of all pointers to 32-bit floating-point  
scalars (if the function has any), followed by the group of all pointers to 32-bit integer scalars. The LabVIEW  
interface to such a custom function, Custom VI, should reflect the same parameter order.  
The number of parameters varies for different functions. To use the Custom VI as the interface for different custom  
functions, you must bundle the same types of parameters to an array. LabVIEW can check the array sizes in the CIN  
to determine how many parameters to pass to a custom function on the DSP board from LabVIEW. For this reason,  
Custom VI uses arrays as input/output parameter types. The number of parameters of a custom function is the sum  
of the sizes of three arrays of the Custom VI.  
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The array of DSP Handle Clusters holds all the references to arrays of data used by the custom DSP functions. You  
should bundle the DSP Handle Clusters together to an array in the order they appear in the first group of parameters  
in the custom function on the DSP board. For example, if the first three parameters of the custom function are the  
arrays X, Y, and Z, which correspond to the DSP Handle Clusters in LabVIEW, hdl1, hdl2, and hdl3, respectively,  
then you must bundle hdl1, hdl2, and hdl3 to an array in that order. The same order requirements apply to the array  
of 32-bit floating-point scalars that holds the LabVIEW parameters corresponding to the second group of the  
parameters in the custom function. Likewise, the array of 32-bit integer scalars that holds the LabVIEW parameters  
corresponding to the third and final group of parameters in the custom function must also have the same order  
requirements as the other arrays.  
Bundle all of the parameters of the same type to an array before you call Custom VI. Remember that the order in  
which you bundle the parameters should correspond to the order of the terminals in the corresponding group of the  
custom function. The first element in the array representing a group should correspond to the first parameter of the  
same group in the custom function, and so on.  
The Custom VI is the interface from LabVIEW to all of the custom functions on the DSP board. Each parameter of  
the custom functions on the DSP board require two corresponding terminals in LabVIEW–an input control to  
reserve the space on the DSP board for the data, and an output indicator to hold the result. All of the output arrays in  
the Custom VI are internally connected to the corresponding input arrays.  
The Custom VI treats all of the parameters in the custom functions as input/output parameters. The parameters that  
represent outputs of the custom function must also be bundled in LabVIEW in the array that holds all of the other  
input parameters of the same type. Although the output parameters, whether scalars or arrays, do not contain any  
valid or useful information on input, they will be overwritten by the return values. The parameters that represent  
inputs to the custom functions also exist in the corresponding output arrays, although the values of the output arrays  
are the same values as on input–the custom function will not change the parameter values.  
Figure 2-6 shows how to bundle the parameters for gmaxmin.c. Allocate two DSP Handle Clusters corresponding  
to the input array z and the output array y. The bundling order is as follows–the DSP Handle Cluster representing z  
is first, followed by the DSP Handle Cluster representing y. y is the output array. The data in this array is not valid  
as an input, but you must still allocate it first and bundle it with other DSP Handle Clusters that represent input  
arrays. Notice that although the parameters max value, min value, max index, and min index are outputs only in  
gmaxmin.c, you must first bundle the additional four input scalars with the actual input parameters to reserve  
space in memory for the parameters on output. The initial values are not important. The parameter n (the number of  
elements) is only an input parameter in gmaxmin.c, but you will still have an output corresponding to this  
parameter, although the output and input values are the same.  
Z
Y
N
Figure 2-6. How to Bundle Parameters in LabVIEW to Call gmaxmin.c  
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2. Call the Custom VI  
After you bundle all of the parameters to arrays, connect each array to the corresponding terminals of the Custom  
VI. Figure 2-7 shows how to connect to the Custom VI for the gmaxmin.c.  
Figure 2-7. How to Connect to Custom VI to Call gmaxmin.c  
If your custom function does not have a certain type of parameter, leave the corresponding terminal unwired. This is  
important for passing your parameters correctly from LabVIEW to the DSP board.  
The value of the function ID is the custom function ID that you obtain from dspfncs.h. This ID determines  
which custom function on the DSP board the Custom VI calls. To call the correct function on the DSP board, you  
must supply the appropriate function ID. In this example, the function ID is 448, which you obtained in step 5 of  
creating your custom NI-DSP Library. Finally, you must indicate the slot number on which to execute the custom  
VI. In Figure 2-6, the slot parameter terminal is left unwired. This causes all VIs to execute on the default DSP  
board, which is set to slot 3.  
3. Index the Output Arrays to Obtain the Results  
All of the output results are in the output arrays of the Custom VI. You can read the output arrays to see the results.  
If you want to operate on some output parameters, use the method for indexing an array to extract an element from  
an array. The order of the output parameters in an output array is identical to the order in the corresponding input  
array.  
Figure 2-8 shows how to index the output arrays of the Custom VI to obtain the results of gmaxmin.c. The  
Custom VI leaves the output data buffers on the board, and returns only the DSP Handle Clusters that indicate the  
locations of these buffers on the board. You must use the Copy Mem(DSP to LV) VI to copy data back to  
LabVIEW. The Custom VI always copies scalars back to LabVIEW.  
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Figure 2-8. Block Diagram–How to Index the Output Arrays of the Custom VI  
to Obtain Results of gmaxmin.c  
Figure 2-9 shows the whole block diagram that uses the Custom VI to call the custom function gmaxmin.con the  
DSP board from LabVIEW. Figure 2-10 shows the front panel of the block diagram shown in Figure 2-9.  
Figure 2-9. Block Diagram–Using the Custom VI to Call gmaxmin.con the  
DSP Board from LabVIEW  
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Figure 2-10. Front Panel–Using the Custom VI to Call gmaxmin.con the  
DSP Board from LabVIEW  
At this point, finish creating the VI interface to call your custom function on the DSP board from LabVIEW. You  
can customize this VI as a subVI using the method described in the LabVIEW User Manual if you want to use this  
VI from your other applications in LabVIEW.  
Executing the Custom Function from LabVIEW  
Run this VI from LabVIEW. Change the input array and display the results.  
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DSP Board Function Overview  
This chapter contains an overview of the prototypes of the C-callable NI-DSP Analysis functions on the DSP board  
that you can use in your custom programs.  
Every NI-DSP Analysis VI calls a function on the DSP board. When you write your own custom functions, you can  
call these functions from your program. These C functions include numerical analysis, signal generation, digital  
signal processing, digital filtering, windowing, and memory management.  
For more information about these functions, refer to the NI-DSP Software Reference Manual for DOS/LabWindows.  
Note: The functions listed in this chapter are the same functions described in the NI-DSP Software Reference  
Manual for DOS/LabWindows, except for the following differences:  
•
•
For all of the functions, ignore the slot number parameter specified in the tables of parameters. The  
slot number is not meaningful when you call these functions from the DSP board.  
The integer parameters are all 32 bits long. The corresponding parameter type in the NI-DSP Software  
Reference Manual for DOS/LabWindows is 16-bit integer. When you call these functions in your  
custom program, use the 32-bit long type defined in this manual. Use the data types defined in this  
manual rather than the data types for similar functions listed in any other manual. The parameter order  
and meaning and the purpose of the functions, however, are equivalent with the functions described in  
the NI-DSP Software Reference Manual for DOS/LabWindows.  
•
The functions listed are all of the functions that you can call from your custom program. Not all the  
functions described in the NI-DSP Software Reference Manual for DOS/LabWindows are available in  
NI-DSP for LabVIEW for Windows.  
The following is a list of the prototypes of each function that you can customize for use on the DSP board.  
Signals  
short DSP_Gaussian (long n, float sDev, float* noise, float seed)  
short DSP_ImpTrain (long n, float amp, long delay, long period, float * x)  
short DSP_Impulse (long n, float amp, long index, float * x)  
short DSP_Pulse (long n, float amp, long delay, long width, float *x)  
short DSP_Ramp (long n, float first, float last, float * x)  
short DSP_Sawtooth (long n, float amp, long delay, float cycles, float * x)  
short DSP_Sinc (long n, float amp, float delay, float dt, float *x)  
short DSP_Sine (long n, float amp, float phase, float cycles, float * x)  
short DSP_Square (long n, float amp, float duty, float cycles, float * y)  
short DSP_Triangle (long n, float amp, float delay, float width,  
float dt, float * x)  
short DSP_TriTrain (long n, float amp, long delay, float cycles, float * x)  
short DSP_Uniform (long n, float * noise, float seed)  
short DSP_WhiteNoise (long n, float amp, float * noise, float seed)  
Frequency Domain  
short DSP_CrossPower (float * x, float * y, long n)  
short DSP_CxFFT (float * x, float * y, long n)  
short DSP_FHT (float * x, long n)  
short DSP_InvFFT (float * x, float * y, long n)  
short DSP_InvFHT (float * x, long n)  
short DSP_ReFFT (float * x, float * y, long n)  
short DSP_Spectrum (float * x, long n)  
short DSP_ZeroPad (float * x, long n, long size)  
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Time Domain  
short DSP_Convolution (float * x, long n, float * y, long m, float * cxy)  
short DSP_Correlation (float * x, long n, float * y, long m, float * rxy)  
short DSP_Decimate (float * x, long n, long decFact, long ave, float * y)  
short DSP_Deconvolution (float * cxy, long n, float * y, long m, float * x)  
short DSP_Difference (float * x, long n, float dt, float xInit,  
float xFinal, float * y)  
short DSP_Integrate (float * x, long n, float dt, float xInit,  
float xFinal, float * y)  
Filters  
short DSP_Bw_Coef  
(float fs, float f_low, float f_hi, long order,  
float * a, float * b, long type)  
short DSP_Ch_Coef  
(float fs, float f_low, float f_hi, long order,  
float ripple, float * a, float * b, long type)  
short DSP_Elp_Coef (float fs, float f_low, float f_hi, long order, float  
ripple, float atten, float * a, float * b, long type)  
short DSP_EqRip_BPF (float * x, long n, long taps, float fs, float fh1,  
float fl2, float fh2, float fl3, float * y)  
short DSP_EqRip_BSF (float * x, long n, long taps, float fs, float fh1,  
float fl2, float fh2, float fl3, float * y)  
short DSP_EqRip_HPF (float * x, long n, long taps, float fs, float fh1,  
float fl2, float * y)  
short DSP_EqRip_LPF (float * x, long n, long taps, float fs, float fh1,  
float fl2, float * y)  
short DSP_IIR_Filter (float * x, long n, float * a, float * Condx, long sza,  
float * b, float * Condy, long szb, float * y)  
short DSP_InvCh_Coef (float fs, float f_low, float f_hi, long order, float  
ripple, float *a, float * b, long type)  
short DSP_Median_Filter (float * x, long n, long rank, float * y)  
short DSP_Parks_McClellan (long n, float fs, long bands, float * Amp, float  
* fLow, float * fHi, float * wRipple, long  
filterType, float * h, float * delta)  
Windows  
short DSP_CosWin(float * x, long n, long type)  
short DSP_ExpWin (float * x, long n, float finalval)  
short DSP_ForceWin (float * x, long n, float duty)  
short DSP_GenCosineWin (float * x, long n, float * coeff, long m)  
short DSP_KsrWin (float * x, long n, float beta)  
short DSP_TriWin (float * x, long n)  
Array Functions  
short DSP_Abs (float * x, long n, float * y)  
short DSP_Add (float * x, float * y, long n, float * z)  
short DSP_Clip (float * x, long n, float upper, float lower, float * y)  
short DSP_Div (float * x, float * y, long n, float * z)  
short DSP_LinEv (float * x, long n, float a, float b, float * y)  
short DSP_Log (float * x, long n, float mult, float * y)  
short DSP_MaxMin  
(float * x, long n, float * max, long * imax, float *  
min, long * imin)  
short DSP_Mul (float * x, float * y, long n, float * z)  
short DSP_PolyEv (float * x, long n, float * coeff,long k, float * y)  
short DSP_Prod (float * x, long n, float * prod)  
short DSP_Reverse (float * x, long n)  
short DSP_Set (float * x, long n, float a)  
short DSP_Shift (float * x, long n, long shift, float * y)  
short DSP_Sort (float * x, long n, long direction, float * y)  
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Chapter 3  
DSP Board Function Overview  
short DSP_Sqrt (float * x, long n, float * y)  
short DSP_Sub (float * x, float * y, long n, flaot * z)  
short DSP_Subset (float * x, long n, long index, long length, float * y)  
short DSP_Sum (float * x, long n, float * sum)  
short DSP_Unwrap (float * x, long n, float * y)  
short DSP_To Polar (float * x, float * y, long n, float * mag,  
float * phase)  
short DSP_To Rect (float * mag, float * phase, long n, float * x,  
float * y)  
Memory Management Data Transfer  
void * Alloc_Mem (long numbytes)  
short DSP_CopyMem  
(void * Source, void * Destination, long type, long  
count)  
short Free_Mem (long ptr)  
Data Acquisition Functions  
Some low-level data acquisition NI-DSP functions are also available for you to call in an application on the DSP  
board. You can use these low-level data acquisition functions to develop acquisition and waveform generation  
applications that occur on the DSP board, such as acquiring and sending data over the input and output channels. If  
you use any of the low-level data acquisition functions in your custom functions, please include the dspdaq.hfile  
in your program. dspdaq.hcontains all the prototypes of functions and the data structures that the data  
acquisition functions use. You can find this header file in the LIBdirectory. For more information about these  
functions, refer to Part 4, Chapter 5, Data Acquisition Functions for the AT-DSP2200, in the NI-DSP Software  
Reference Manual for DOS/LabWindows. All of the information in that chapter applies to the NI-DSP software for  
LabVIEW for Windows.  
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Chapter 4  
Using the DMA VIs  
____________________________________________________________________________________________  
This chapter describes two special VIs that transfer data between the host computer and the DSP board without  
interfering with the DSP board.  
Most VIs in the NI-DSP library run sequentially on the DSP board. In other words, if you run a VI from LabVIEW,  
even though the actual function is running on the board, LabVIEW must wait for the function to finish before it can  
do anything else. If you have a custom function that runs indefinitely on the board, LabVIEW will continue to wait.  
However, every VI has the ability to check for timeout errors, and you can use the DSP Timeout VI to resolve this  
problem by setting a timeout limit. The host will wait for the DSP board to finish an operation for only the amount  
of time you designate; if the DSP board does not complete the function in the specified amount of time, the VI will  
return a timeout error. If your custom function runs a long time or indefinitely, you can set a very short timeout  
period and ignore the timeout error in your LabVIEW program. However, under these conditions you normally lose  
communication with the DSP board until you reset it with the DSP Reset VI.  
Two VIs–DSP DMA Copy(LV to DSP) and DSP DMA Copy(DSP to LV)–solve this communication problem.  
These two VIs can transfer data between the host and the DSP board using onboard DMA without interfering with  
the DSP board. You can use the DSP DMA Copy(LV to DSP) VI to send data to a designated memory location on  
the DSP board from LabVIEW when the DSP board is still running. The function running on the board can read  
data from that location and update operations that depend on that data. LabVIEW can also read data back from the  
DSP board using the DSP DMA Copy(DSP to LV) VI to check the status of the board or read results while the board  
is still running. In other words, you can still communicate with the board.  
When you use the DSP DMA Copy(DSP to LV) and DSP DMA Copy(LV to DSP) VIs, remember the following:  
•
These two VIs require a real DSP address to transfer data. You can determine this address in two ways:  
-
Give a valid DSP address, such as FFF000 hex, if you know the exact DSP memory address of a buffer or  
variable that your DSP program will use.  
-
Allocate a normal DSP Handle Cluster and use the DSP Handle To Address VI to obtain the valid DSP  
address for this DSP Handle Cluster. You can use this DSP address in your program on the DSP board as  
you would use any pointer. Remember to allocate the DSP Handle Cluster before you call your custom  
function through the DSP Custom Function VI.  
•
•
The data format will not change when you transfer data. If the data is floating point, you need to convert the  
data format in your code between DSP format and IEEE format. When you send floating-point data from  
LabVIEW to the DSP board, convert the data to DSP format before using it in your program on the DSP board.  
When you copy floating-point data back from the DSP board to LabVIEW, convert the data to IEEE format  
before you save it to the DSP memory location from which you will copy data.  
Do not use data acquisition VIs to acquire data to PC memory or send data from PC to DSP memory while  
using these two VIs, because these VIs use the same DSP board register, PDR, to transfer data.  
Two examples shipped with this package show you how to make use of these VIs. The examples are installed in the  
Examplessubdirectory of your NI-DSP package.  
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Using the DMA VIs  
Chapter 4  
The first example is a simple spectral analyzer. The main VI is called Analyzer VI. It uses the DSP Custom  
Function VI to call a custom function running on the board. The scheme is as follows:  
•
Custom function on the board:  
1. Set the data acquisition parameter and initialize the board.  
2. Start the data acquisition.  
while(TRUE) {  
when data is ready, copy it to the process buffer  
read processing information from DSP memory location 1  
depending on the processing information  
apply the selected window to the data  
apply the selected filter to the data  
compute the FFT magnitude or Power Spectrum  
Transfer the data format to IEEE format.  
Save processed data in DSP memory location 2.  
}
•
In LabVIEW:  
1. Initialize the board and set parameters.  
2. Allocate DSP Handle Cluster 1; get the address for this handle (this is DSP memory location 1).  
3. Allocate DSP Handle Cluster 2; get the address for this handle (this is DSP memory location 2).  
4. Set a timeout limit to a very small number (2 ms).  
5. Pass DSP Handle Cluster 1 and 2 with the other necessary parameters to the DSP Custom Function VI and  
call the Analyzer VI.  
6. Ignore the timeout error returned from the DSP Custom Function VI.  
While(STOP button not pressed) {  
send new processing information (you can change certain processing  
controls from the front panel) to DSP memory location 1 using the  
DSP DMA Copy(LV to DSP) VI.  
copy the processed data from DSP memory location 2 to LabVIEW and  
plot the data.  
}
7. Call the DSP Reset VI to reset the DSP board.  
The second example is the audio equalizer example. The VI loads the audio equalizer kernel called audio.out  
using the DSP Load VI. It uses the DSP DMA Copy(LV to DSP) VI to send the new gains for each channel to the  
DSP board and uses the DSP DMA Copy(DSP to LV) VI to copy the processed audio data back to LabVIEW and  
then plots the data.  
You can find all of the source codes and VIs for these two examples in the Examplessubdirectory of your NI-DSP  
package.  
These examples show you how to use the DSP DMA Copy(DSP to LV) and DSP DMA Copy(LV to DSP) VIs to  
communicate between the DSP board and the host computer. They also show you how to run parallel DSP and  
LabVIEW applications, which makes the board more flexible and powerful. With a well-designed system, you can  
gain both speed and flexibility.  
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Chapter 4  
Using the DMA VIs  
DSP DMA Copy(DSP to LV)  
Copies a buffer of size elements  
from source(DSP Address) on  
the DSP board to one of the  
destination arrays in LabVIEW  
using the onboard DMA transfer  
method.  
This VI uses only the DMA controller on the DSP board to transfer data. Therefore, it does not interfere with the  
other program that is running on the DSP board.  
Note: This VI does not convert floating-point data to the IEEE format while copying. When you copy floating  
data, convert to IEEE format in your program on the DSP board. However, the Copy Mem(DSP to LV) VI  
automatically converts data format during the copying procedure.  
To copy data correctly from the DSP board to LabVIEW, you must indicate what type of data is stored in the  
source(DSP Address) buffer on the DSP board, set the destination type to the appropriate type, and wire to the  
corresponding destination terminal. This VI has three destination types–float (32-bit), short (16-bit), and long  
(32-bit). Remember, you must wire only one destination terminal.  
slot is the board ID number. slot defaults to 3.  
source(DSP Address) is the actual DSP address from which you copy your data. It should be a  
24-bit integer (such as FFF000 hex) less than or equal to FFFFFF hex. If you know the exact DSP  
address where your data is stored, use this address directly. Alternatively, you can use the DSP  
Handle To Address VI to convert a DSP Handle Cluster to an actual DSP address.  
size indicates the amount of data you want to copy back from the source(DSP Address) buffer on  
the DSP board to the destination buffer in the LabVIEW. size defaults to 0.  
destination type indicates the type of the data in the source(DSP Address) buffer on the DSP board.  
It has three options:  
0: 32-bit floating-point.  
1: 16-bit short integer.  
3: 32-bit long integer.  
destination type defaults to 32-bit floating-point.  
destination(float) is the terminal to which you must wire the destination buffer if the data you want  
to copy is a 32-bit floating-point data array. Remember, the program on the DSP board must convert  
this data to IEEE format before it is copied.  
destination(short) is the terminal to which you must wire the destination buffer if the data you want  
to copy is a 16-bit short data array.  
destination(long) is the terminal to which you must wire the destination buffer if the data you want  
to copy is a 32-bit long data array.  
error in(no error) contains the error information from a previous VI. If an error occurs, it is passed  
out error out and no other calls are made.  
error out contains the error information for this call.  
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Using the DMA VIs  
Chapter 4  
DSP DMA Copy(LV to DSP)  
Copies the data in the LabVIEW array  
source to the destination(DSP  
Address) on the DSP board using the  
onboard DMA method.  
This VI uses only the DMA controller  
on the DSP board to transfer data.  
Therefore, it does not interfere with  
the other program that is running on  
the DSP board unless you copy the  
data to the DSP memory location that  
is being used by the other program.  
Note: This VI does not convert floating-point data to DSP format while copying. When you copy floating data,  
convert to DSP format in your program on the DSP board before using this data. However, the Copy  
Mem(LV to DSP) VI automatically converts data format during the copying procedure.  
The source buffer can contain one of three kinds of data–float (32-bit), short (16-bit), and long (32-bit). To copy  
different types of data, you must wire the source data buffer to the appropriate source terminal. For example, if you  
want to copy floating data, you must wire the data buffer to the terminal source(float). You must wire only one  
source terminal. The destination buffer must be large enough to contain all of the data from the source buffer.  
slot is the board ID number. slot defaults to 3.  
source(float) is the terminal to which you must wire the source buffer if the data you want to copy is  
a 32-bit floating-point data array. Remember, the program on the DSP board must convert this data  
to DSP format before using it.  
source(long) is the terminal to which you must wire the source buffer if the data you want to copy is  
a 32-bit long data array.  
source(short) is the terminal to which you must wire the source buffer if the data you want to copy  
is a 16-bit long data array.  
destination(DSP Address) is the actual DSP address to which you want to copy your data. It should  
be a 24-bit integer (such as FFF000 hex) less than or equal to FFFFFF hex. If you know the exact  
DSP address where you want to store the data, you can use this address directly. Alternatively, you  
can use the DSP Handle To Address VI to convert a DSP Handle Cluster to an actual DSP address.  
error in(no error) contains the error information from a previous VI. If an error occurs, it is passed  
out error out and no other calls are made.  
error out contains the error information for this call.  
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Appendix A  
Error Codes  
This appendix contains a list of the error codes returned by the NI-DSP Analysis VIs and the corresponding error  
messages.  
Error Conditions  
If an error condition occurs during execution of any of the VIs in the NI-DSP Analysis, the VI returns an error code.  
This code is a value which indicates the type of error that occurred. The currently defined error codes and their  
associated meanings are given in Table A-1. For error codes other than those listed, refer to the NI-DAQ Software  
Reference Manual for DOS/Windows/LabWindows.  
Table A-1. NI-DSP Analysis Library Error Codes  
Error  
Error Name  
Description  
Number  
0
-10401  
-10005  
-10403  
-10444  
-10243  
-10247  
-10459  
-21204  
-21205  
-21206  
-21207  
-21208  
-21209  
noError  
No error; the call was successful.  
unknownDeviceErr  
badDeviceErr  
deviceSupportErr  
memFullErr  
The board specified is not a National Instruments DSP board.  
The board number used in function call should be 1<board<8.  
Function cannot be executed by specified board.  
Insufficient memory or disk space.  
configFileErr  
cmosConfigErr  
DLLInterfaceErr  
SamplesGTZero  
SamplesGEZero  
SamplesGETwo  
SizesGTZero  
Board configuration file not found.  
EISA system configuration invalid.  
The DLL could not be called due to an interface error.  
The number of samples must be greater than zero.  
The number of samples must be greater than or equal to zero.  
The number of samples must be greater than or equal to two.  
The sizes of the input sequences must be greater than zero.  
The size of x must be greater than or equal to the size of y.  
xSizeGEySize  
OutSizeGEInSize  
The output array size must be greater than or equal to the input  
array size.  
-21210  
-21212  
OutOfMem  
There is not enough space left on the DSP board for onboard  
processing.  
DecFactErr  
The decimating factor must meet: 0 < decimating factor ≤  
samples.  
-21213  
-21214  
-21215  
-21216  
-21217  
WidthLTSamples  
IndexLTSamples  
DelayGEZero  
The width must meet: 0 < width < samples.  
The index must meet: 0 ≤ index < samples.  
The delay must be greater than or equal to zero.  
The width must be greater than or equal to zero.  
WidthGEZero  
DelayWidthErr  
The following condition must be met:  
0 ≤ (delay + width) < samples.  
(continues)  
© National Instruments Corporation  
A-1  
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Error Codes  
Appendix A  
Table A-1. NI-DSP Analysis Library Error Codes (Continued)  
Error  
Error Name  
Description  
Number  
-21218  
-21219  
-21220  
-21221  
WinDutyCyclesErr  
dtGTZero  
The window duty cycle value must be between 0.0 and 100.0.  
dt must be greater than zero.  
DutyCycleErr  
CyclesErr  
The duty cycle must meet: 0 ≤ duty cycle ≤ 100.  
The number of cycles must be greater than zero and less than or  
equal to the number of samples.  
-21223  
-21225  
-21226  
-21227  
-21228  
-21229  
UpperGELower  
IntervalNumErr  
MixedSignErr  
SizeGTOrder  
OrderGTZero  
ConvSizeErr  
The upper value must be greater than or equal to the lower value.  
The number of intervals must be greater than zero.  
The sign of y in Ax=y values must be all positive or negative.  
The array size must be greater than the order.  
The order must be greater than zero.  
The number of elements of convolved arrays should be greater  
than zero.  
-21233  
-21234  
NyquistErr  
Nyquist2Err  
The cutoff frequency, fc, must meet: 0 ≤ fc≤ fs/2.  
The following conditions must be met:  
0 ≤ f_low ≤ f_high ≤ fs/2.  
-21235  
-21236  
-21237  
-21242  
-21243  
-21245  
-21246  
-21248  
-21249  
-21250  
-21251  
-21297  
RippleGTZero  
AttenGTZero  
WidthGTZero  
SizeGTZero  
NullVectorErr  
AttenGTRipple  
StepSizeErr  
LeakErr  
The ripple amplitude must be greater than zero.  
The attenuation must be greater than zero.  
The width must be greater than zero.  
The size of the input sequence must be greater than zero.  
The input vector is null. The unit vector does not exist.  
The attenuation must be greater than the ripple amplitude.  
The step-size parameter µ must meet: 0 ≤ µ ≤ 0.1.  
The leakage coefficient, Leak, must meet: 0 ≤ Leak ≤ µ.  
The filter cannot be designed with the specified input parameters.  
The number of coefficients must be greater than or equal to one.  
The rank of the filter must meet: 1 ≤ (2 rank +1) ≤ size.  
FilterDesignErr  
LenGEOne  
RankErr  
NotPowerOfTwo  
The size of the input array must be a valid power of two:  
size = 2m, 0 < m < 14.  
-21301  
MEM_HRDWARE_ERR  
The onboard hardware diagnostic software found a memory  
hardware error. Running functions on the board is unreliable.  
-21302  
-21303  
ZERO_ALLOCATION  
TooBigAnOffset  
There are no allocated buffers on the DSP board.  
The indexing requested falls outside of the buffer into which  
indexing is requested.  
-21304  
-21305  
HandleNotFound  
TooManyAllocs  
The DSP Handle specified is not found on this board: it has  
either been freed or never allocated.  
The Memory Look Up Table is full: no more allocations allowed  
before freeing up some DSP handles (maximum allowed = 128).  
-21306  
-21307  
PtrNotFound  
ParamSizeErr  
The DSP address pointer could not be found to free the buffer.  
One of the parameters does not have enough space allocated for  
it on the board.  
(continues)  
NI-DSP SRM for LabVIEW for Windows  
A-2  
© National Instruments Corporation  
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Appendix A  
Error Codes  
Table A-1. NI-DSP Analysis Library Error Codes (Continued)  
Error Name Description  
Error  
Number  
-21308  
-21309  
-21310  
TransferSizeErr  
NotDSPHandle  
The size of requested block transfer does not have enough space  
allocated for it on the board.  
The DSP Handle specified is not valid for this board:  
it has either been freed or never allocated.  
HandleSlotErr  
The DSP Handle used does not belong to the same board on  
which the function request is made.  
-21311  
-21312  
HandleAllocErr  
TimeOutErr  
Failed to allocate a handle in the interface code.  
The Kernel did not respond or finish function execution in the  
selected timeout.  
-21313  
-21314  
COFF_FilePathErr  
CoffHdrErr  
Could not find the DSP Library file in the directory set by the  
DAQCONFutility.  
The file you are attempting to load to the DSP board is not  
created using the WE DSP32C tools (not an acceptable  
COFF file).  
-21315  
-21317  
CoffSectErr  
AddrSpaceErr  
Found an unimplemented section flag in the COFF file.  
The COFF file you are trying to load is linked with a memory  
map that exceeds the maximum memory space allowed by the  
WE DSP32C chip (224).  
-21318  
NoBrdRespToTransfer  
The DSP board on which you are trying to load the COFF file is  
not responding to the transfer of the file. Check if there is a  
board in the slot desired and verify with the DAQCONFutility.  
-21324  
-21325  
FNC_ERR  
The function ID specified does not correspond to a function that  
is part of the DSP Library currently running on the board.  
GROUP_ERR  
The function ID specified does not belong to any group that is  
part of the DSP Library currently running on the board.  
-21331  
-21332  
-21333  
NotFindFunctionInDLL  
LoadDLLLibErr  
An error occurs when loading dsp.dlllibrary in CIN.  
An error occurs when loading a function in dsp.dll in CIN.  
ErrInGetFunctionHandle An error occurs when calling the  
GetIndirectFunctionHandlefunction in CIN.  
-21334  
InvalidBytesSelect  
bytes/element selector can only select between 4 bytes(0) and 2  
bytes(1).  
-21336  
-21337  
AllocArrayFailed  
InvalidArrayType  
Failed to allocate a LabVIEW array.  
The array type can only be 32-bit floating point data(0), 16-bit  
long integer data(1) or 32-bit short integer data(2).  
-21338  
-21339  
PathnameTooLong  
InvalidCopyType  
The path name should be less than 256 characters.  
The entire/partial copy selector can only select between entire  
copy (0) and partial copy(1).  
-21340  
-21341  
-21342  
CopyNumGTZero  
OffsetGEZero  
The number of data to copy should be greater than zero.  
The offset should be greater than or equal to zero.  
IndexSizeGTZero  
The size of the New DSP Handle Cluster should be greater than  
zero.  
(continues)  
© National Instruments Corporation  
A-3  
NI-DSP SRM for LabVIEW for Windows  
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Error Codes  
Appendix A  
Table A-1. NI-DSP Analysis Library Error Codes (Continued)  
Error Name Description  
Error  
Number  
-21343  
IndexSizeOffsetErr  
The size+offset should be less than or equal to the size of the  
DSP Handle Cluster that you index into.  
-21344  
-21345  
InvalidDataType  
NumBytesGTZero  
The data type can only be 4 bytes long(0) or 2 bytes long(1) .  
The number of bytes to allocate should be greater than zero.  
NI-DSP SRM for LabVIEW for Windows  
A-4  
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Appendix B  
Customer Communication  
For your convenience, this appendix contains forms to help you gather the information necessary to help us solve  
technical problems you might have as well as a form you can use to comment on the product documentation. Filling  
out a copy of the Technical Support Form before contacting National Instruments helps us help you better and faster.  
National Instruments provides comprehensive technical assistance around the world. In the U.S. and Canada,  
applications engineers are available Monday through Friday from 8:00 a.m. to 6:00 p.m. (central time). In other  
countries, contact the nearest branch office. You may fax questions to us at any time.  
Corporate Headquarters  
(512) 795-8248  
Technical support fax:  
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™
®
Title: NI-DSP Software Reference Manual for LabVIEW for Windows  
Edition Date:  
Part Number:  
December 1993  
320571-01  
Please comment on the completeness, clarity, and organization of the manual.  
If you find errors in the manual, please record the page numbers and describe the errors.  
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6504 Bridge Point Parkway, MS 53-02  
Austin, TX 78730-5039  
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Glossary  
___________________________________________________  
Prefix  
Meaning  
Value  
-9  
-6  
-3  
3
n-  
nano-  
micro-  
milli-  
kilo-  
10  
10  
10  
10  
µ-  
m-  
k-  
6
M-  
mega-  
10  
1D  
2D  
Cx  
one-dimensional  
two-dimensional  
complex  
dB  
decibels  
Discrete Fourier Transform  
direct memory access  
digital signal processing  
Fast Fourier Transform  
Fast Hartley Transform  
DFT  
DMA  
DSP  
FFT  
FHT  
FIR  
hex  
finite impulse response (filter)  
hexadecimal  
IDFT  
IEEE  
IFFT  
IFHT  
IIR  
Inverse Discrete Fourier Transform  
Institute of Electrical and Electronic Engineers  
Inverse Fast Fourier Transform  
Inverse Fast Hartley Transform  
infinite impulse response (filter)  
input/output  
I/O  
Kwords  
LMS  
LSB  
LV  
1,024 words of memory  
least mean square  
least significant bit (of a word)  
LabVIEW  
MB  
megabytes of memory  
MLUT  
MSE  
Mwords  
pt  
RTSI  
SCXI  
s
Memory Look Up Table  
mean squared error  
1,024 x 1,024 words of memory  
point  
Real-Time System Integration  
Signal Conditioning eXtensions for Instrumentation  
seconds  
word  
32-bits of memory or four bytes, unless otherwise stated  
© National Instruments Corporation  
Glossary-1  
NI-DSP SRM for LabVIEW for Windows  
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Index  
A
B
Alloc_Mem function, Part 4: 2-3  
array VIs  
bandpass filters. See filter VIs.  
DSP Absolute, Part 3: 2-4  
DSP Add, Part 3: 2-5  
DSP Clip, Part 3: 2-11  
DSP Divide, Part 3: 2-20  
DSP Linear Evaluation, Part 3: 2-50  
DSP Log, Part 3: 2-51  
DSP Max & Min, Part 3: 2-52  
DSP Multiply, Part 3: 2-54  
DSP Polar to Rectangular, Part 3 3-59  
DSP Polynomial Evaluation, Part 3: 2-58  
DSP Product, Part 3: 2-59  
DSP Rectangular to Polar, Part 3: 3-65  
DSP Reverse, Part 3: 2-64  
DSP Set, Part 3: 2-66  
bandstop filters. See filter VIs.  
boards. See also AT-DSP2200 board.  
compatibility of DSP boards with National  
Instruments data acquisition boards, xv  
configuration  
EISA bus computer, Part 1: 1-3  
ISA (or AT) bus computer, Part 1: 1-3  
build Dispatch application. See Dispatch application.  
Butterworth filter. See DSP Butterworth  
Coefficients VI.  
C
DSP Shift, Part 3: 2-66  
Chebyshev filter. See DSP Chebyshev Coefficients  
VI; DSP Inv Chebyshev Coeff VI.  
Code Interface Node (CIN) interface, Part 2: 1-2  
COFF (common object file format) file, Part 4: 1-1  
compatibility of DSP boards with National  
Instruments data acquisition boards, xv  
compiling and assembling custom libraries,  
Part 4: 2-4, 2-7 to 2-8  
DSP Sort, Part 3: 2-71  
DSP Square Root, Part 3: 2-70  
DSP Subset, Part 3: 2-72  
DSP Subtract, Part 3: 2-73  
DSP Sum, Part 3: 2-73  
DSP Unwrap Phase, Part 3: 2-80  
list of functions, Part 3: 1-2  
prototypes for customizable functions,  
Part 4: 3-2 to 3-3  
configuration. See boards.  
Copy Mem(DSP to DSP) VI, Part 3: 2-1  
Copy Mem(DSP to LV) VI, Part 3: 2-2  
Copy Mem(LV to DSP) VI, Part 3: 2-3  
custom NI-DSP library, creating, Part 4: 2-1 to 2-8  
adding function names to library function list  
file, Part 4: 2-4 to 2-5  
assembling custom libraries, Part 4: 2-7 to 2-8  
assembling source code, Part 4: 2-4  
makelib.bat file, Part 4: 2-8  
procedure, Part 4: 2-7 to 2-8  
required files, Part 4: 2-7  
using WE DSP32C assembly language,  
Part 4: 2-3 to 2-4  
assembly dispatch file, generating, Part 4: 2-6  
AT-DSP2200 board  
adding object filenames to linker file (ifile),  
Part 4: 2-4  
assembling source code, Part 4: 2-4  
compiling and assembling, Part 4: 2-7 to 2-8  
compiling source code, Part 4: 2-4  
deleting (replacing) function names in  
NIDSP.fnc, Part 4: 2-5  
board configuration  
EISA bus computer, Part 1: 1-3  
ISA (or AT) bus computer, Part 1: 1-3  
capabilities, xv  
files required to build example library,  
Part 4: 2-7  
DSP library files, Part 1: 1-3  
improving execution speed of DSP VIs,  
Part 2: 1-7  
memory management and data transfer,  
Part 2: 1-2 to 1-4  
generating dispatch file, Part 4: 2-6  
GMaxMin.c example, Part 4: 2-1 to 2-2  
guidelines for adding functions, Part 4: 2-2 to 2-3  
including error codes, Part 4: 2-2  
LabVIEW interface, creating, Part 4: 2-8 to 2-12  
bundling input parameters to arrays,  
Part 4: 2-8 to 2-9  
software overview, Part 2: 1-1 to 1-2  
ATDSP.h file, Part 4: 2-2  
AT&T WE DSP32C digital signal processor,  
Part 4: 1-1  
calling Custom VI, Part 4: 2-10  
executing custom function from LabVIEW,  
Part 4: 2-12  
© National Instruments Corporation  
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Index  
indexing output arrays to obtain results,  
Part 4: 2-10 to 2-12  
linking, Part 4: 2-7 to 2-8  
makelib.bat file, Part 4: 2-8  
memory management, Part 4: 2-3  
parameter guidelines, Part 4: 2-2 to 2-3  
prototypes for customizable functions,  
Part 4: 3-1 to 3-3  
source code creation, Part 4: 2-1 to 2-3  
steps for creating, Part 4: 2-1  
using WE DSP32C assembly language,  
Part 4: 2-3 to 2-4  
DSP Divide VI, Part 3: 2-20  
DSP DMA Copy(DSP to LV) VI, Part 4: 4-3  
DSP DMA Copy(LV to DSP) VI; Part 4: 4-4  
DSP Elliptic Coefficients VI, Part 3: 2-21 to 2-22  
DSP Equi-Ripple BandPass VI, Part 3: 2-23 to 2-24  
DSP Equi-Ripple BandStop VI, Part 3: 2-25 to 2-26  
DSP Equi-Ripple HighPass VI, Part 3: 2-27 to 2-28  
DSP Equi-Ripple LowPass VI, Part 3: 2-29  
DSP Exact Blackman Window VI, Part 3: 2-30  
DSP Exponential Window VI, Part 3: 2-31  
DSP FHT VI, Part 3: 2-32  
DSP Flat Top Window VI, Part 3: 2-33  
DSP Force Window VI, Part 3: 2-34  
DSP Free Memory VI, Part 3: 2-34  
DSP Gaussian White Noise VI, Part 3: 2-35  
DSP General Cosine Window VI, Part 3: 2-36  
DSP Hamming Window VI, Part 3: 2-37  
DSP Handle Clusters  
Custom VI. See DSP Custom VI.  
customer communication, xv, B-1  
D
allocation examples, Part 2: 1-4  
array data type, Part 2: 1-4  
bundling for LabVIEW interface,  
Part 4: 2-8 to 2-9  
definition, Part 2: 1-2, Part 2: 1-3  
hexadecimal encoding, Part 2: 1-3  
illustration, Part 2: 1-3  
improving execution speed of DSP VIs,  
Part 2: 1-7  
input/output, Part 2: 1-5  
memory management and data transfer,  
Part 2: 1-2 to 1-4  
obtaining valid DSP Handle Cluster, Part 2: 1-4  
output data buffers, Part 2: 1-5  
data acquisition functions, Part 4: 3-3  
data buffers. See DSP Handle Clusters.  
data transfer. See memory management and data  
transfer.  
data types  
DSP Handle Cluster as array data type,  
Part 2: 1-4  
icons representing (table), xiii  
deleting (replacing) functions in NIDSP.fnc file,  
Part 4: 2-5  
Developer Toolkit, xv  
DFT (Discrete Fourier Transform), Part 3: 1-4 to 1-5  
Dispatch application, Part 4: 1-1, Part 4: 2-6  
documentation  
values not to be changed, Part 2: 1-3  
Z in, Z out naming convention, Part 2: 1-5  
DSP Handle to Address VI; Part 3: 2-38  
DSP Hanning Window VI, Part 3: 2-38  
DSP IIR Filter VI, Part 3: 2-39 to 2-40  
DSP Impulse Pattern VI, Part 3: 2-41  
DSP Impulse Train Pattern VI, Part 3: 2-42  
DSP Index Memory VI, Part 3: 2-43  
DSP Init Memory VI, Part 3: 2-44  
DSP Integral VI, Part 3: 2-45  
DSP Inv Chebyshev Coeff VI, Part 3: 2-46 to 2-47  
DSP Inverse FFT VI, Part 3: 2-47  
DSP Inverse FHT VI, Part 3: 2-48  
DSP Kaiser-Bessel Window VI,Part 3: 2-49  
DSP Linear Evaluation VI, Part 3: 2-50  
DSP Load VI, Part 3: 2-50  
conventions used in manual, xii-xiii  
organization of manual, xi-xii  
related documentation, xiv  
DSP Absolute function, Part 3: 2-4  
DSP Add function  
DSP Handle Cluster input/output example,  
Part 2: 1-5  
purpose and use, Part 3: 2-5  
DSP Allocate Memory function, Part 3: 2-6  
DSP Blackman Harris Window VI, Part 3: 2-8  
DSP Blackman Window VI, Part 3: 2-7  
DSP Butterworth Coefficients VI, Part 3: 2-9 to 2-10  
DSP Chebyshev Coefficients VI, Part 3: 2-10 to 2-11  
DSP Clip VI, Part 3: 2-11  
DSP Complex FFT VI, Part 3: 2-12  
DSP Convolution VI, Part 3: 2-13  
DSP Correlation VI, Part 3: 2-14  
DSP Cross Power VI, Part 3: 2-15  
DSP Custom VI  
DSP Log VI, Part 3: 2-51  
DSP Max & Min VI, Part 3: 2-52  
DSP Median Filter VI, Part 3: 2-53  
DSP Multiply VI, Part 3: 2-54  
DSP Parks McClellan VI, Part 3: 2-55 to 2-57  
DSP Polar to Rectangular VI; Part 3: 59  
DSP Polynomial Evaluation VI, Part 3: 2-58  
DSP Power Spectrum VI, Part 3: 2-59  
DSP Product VI, Part 3: 2-59  
calling from LabVIEW interface, Part 4: 2-10  
definition, Part 4: 2-9  
executing from LabVIEW interface, Part 4: 2-12  
purpose and use, Part 3: 2-16  
DSP Decimate VI, Part 3: 2-17  
DSP Deconvolution VI, Part 3: 2-18  
DSP Derivative VI, Part 3: 2-19  
DSP Pulse Pattern VI, Part 3: 2-60  
NI-DSP SRM for LabVIEW for Windows  
Index-2  
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Index  
DSP Ramp Pattern VI, Part 3: 2-61  
DSP Random Pattern VI, Part 3: 2-62  
DSP Rectangular to Polar VI; Part 3: 65  
DSP ReFFT VI, Part 3: 2-63  
DSP Parks McClellan, Part 3: 2-55 to 2-57  
list of functions, Part 3: 1-2  
prototypes for customizable functions,  
Part 4: 3-2  
DSP Reset VI, Part 3: 2-63  
filtering algorithms, Part 3: 1-5 to 1-6  
DSP Reverse VI, Part 3: 2-64  
DSP Sawtooth Pattern VI, Part 3: 2-65  
DSP Set VI, Part 3: 2-66  
FIR (Finite Impulse Response) filters, Part 3: 1-6  
Free_Mem function, Part 4: 2-3  
frequency domain VIs  
DSP Shift VI, Part 3: 2-66  
DSP Complex FFT, Part 3: 2-12  
DSP Cross Power, Part 3: 2-15  
DSP FHT, Part 3: 2-32  
DSP Inverse FFT, Part 3: 2-47  
DSP Inverse FHT, Part 3: 2-48  
DSP Power Spectrum, Part 3: 2-59  
DSP ReFFT, Part 3: 2-63  
DSP Sinc Pattern VI, Part 3: 2-67  
DSP Sine Pattern VI, Part 3: 2-68  
DSP Sort VI, Part 3: 2-71  
DSP Square Pattern VI, Part 3: 2-69  
DSP Square Root VI, Part 3: 2-70  
DSP Start VI, Part 3: 2-72  
DSP Subset VI, Part 3: 2-72  
DSP Subtract VI, Part 3: 2-73  
DSP Sum VI, Part 3: 2-73  
DSP Zero Padder, Part 3: 2-81  
Fast Fourier Transform (FFT), Part 3: 1-4 to 1-5  
list of functions, Part 3: 1-1  
DSP Timeout VI, Part 3: 2-74  
DSP Triangle Pattern VI, Part 3: 2-75 to 2-76  
DSP Triangular Train VI, Part 3: 2-77  
DSP Triangular Window VI, Part 3: 2-78  
DSP Uniform White Noise VI, Part 3: 2-79  
DSP Unwrap Phase VI, Part 3: 2-80  
DSP Zero Padder VI, Part 3: 2-81  
dspfncs.h file, Part 4: 2-6  
prototypes for customizable functions,  
Part 4: 3-1  
Functions Menu, Part 3: 1-4  
H
Handles. See DSP Handle Clusters.  
hardware. See boards.  
header files  
ATDSP.h, Part 4: 2-2  
dspfncs.h, Part 4: 2-6  
highpass filters. See filter VIs.  
E
EISA bus computers, Part 1: 1-3  
error codes  
ATDSP.h file, Part 4: 2-2  
error conditions, A-1 to A-4  
error in/error out cluster, Part 2: 1-5 to 1-7  
I
IDFT (Inverse Discrete Fourier Transform),  
Part 3: 1-4  
IIR (Infinite Impulse Response) filters, Part 3: 1-6.  
See also filter VIs.  
installation  
F
board configuration  
Fast Fourier Transform (FFT), Part 3: 1-4 to 1-5.  
See also frequency domain VIs.  
fax technical support, B-1  
FFT. See Fast Fourier Transform (FFT).  
filter VIs  
EISA bus computer, Part 1: 1-3  
ISA (or AT) bus computer, Part 1: 1-3  
NI-DSP for LabVIEW for Windows,  
Part 1: 1-2 to 1-3  
NI-DSP Interface Utilities, Part 4: 1-2  
Interface Utilities. See NI-DSP Interface Utilities.  
Inverse Discrete Fourier Transform (IDFT),  
Part 3: 1-4  
DSP Butterworth Coefficients,  
Part 3: 2-9 to 2-10  
DSP Chebyshev Coefficients,  
Part 3: 2-10 to 2-11  
ISA (or AT) bus computers, Part 1: 1-3  
DSP Elliptic Coefficients, Part 3: 2-21 to 2-22  
DSP Equi-Ripple BandPass, Part 3: 2-23 to 2-24  
DSP Equi-Ripple BandStop, Part 3: 2-25 to 2-26  
DSP Equi-Ripple HighPass, Part 3: 2-27 to 2-28  
DSP Equi-Ripple LowPass, Part 3: 2-29  
DSP IIR Filter, Part 3: 2-39 to 2-40  
DSP Inv Chebyshev Coeff, Part 3: 2-46 to 2-47  
DSP Median Filter, Part 3: 2-53  
K
Kaiser-Bessel window. See DSP Kaiser-Bessel  
Window VI.  
© National Instruments Corporation  
Index-3  
NI-DSP SRM for LabVIEW for Windows  
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Index  
DSP Add, Part 3: 2-5  
L
DSP Allocate Memory, Part 3: 2-6  
DSP Blackman Harris Window, Part 3: 2-8  
DSP Blackman Window, Part 3: 2-7  
DSP Butterworth Coefficients,  
Part 3: 2-9 to 2-10  
DSP Chebyshev Coefficients,  
Part 3: 2-10 to 2-11  
DSP Clip, Part 3: 2-11  
DSP Complex FFT, Part 3: 2-12  
DSP Convolution, Part 3: 2-13  
DSP Correlation, Part 3: 2-14  
DSP Cross Power, Part 3: 2-15  
DSP Custom, Part 3: 2-16  
LabVIEW software. See NI-DSP for LabVIEW for  
Windows.  
Linear Constant Coefficient Difference Equation,  
Part 3: 1-5  
linker file (ifile), Part 4: 2-4  
linking custom libraries, Part 4: 2-7 to 2-8  
lowpass filters. See filter VIs.  
M
makelib.bat file, Part 4: 2-8  
DSP Decimate, Part 3: 2-17  
manual. See documentation.  
Memory Look Up Table (MLUT)  
definition, Part 2: 1-3  
DSP Deconvolution, Part 3: 2-18  
DSP Derivative, Part 3: 2-19  
DSP Divide, Part 3: 2-20  
number of entries allowed, Part 2: 1-3  
memory management and data transfer,  
Part 2: 1-2 to 1-4  
DSP Elliptic Coefficients, Part 3: 2-21 to 2-22  
DSP Equi-Ripple BandPass, Part 3: 2-23 to 2-24  
DSP Equi-Ripple BandStop, Part 3: 2-25 to 2-26  
DSP Equi-Ripple HighPass, Part 3: 2-27 to 2-28  
DSP Equi-Ripple LowPass, Part 3: 2-29  
DSP Exact Blackman Window, Part 3: 2-30  
DSP Exponential Window, Part 3: 2-31  
DSP FHT, Part 3: 2-32  
DSP Flat Top Window, Part 3: 2-33  
DSP Force Window, Part 3: 2-34  
DSP Free Memory, Part 3: 2-34  
DSP Gaussian White Noise, Part 3: 2-35  
DSP General Cosine Window, Part 3: 2-36  
DSP Hamming Window, Part 3: 2-37  
DSP Handle Cluster input/output, Part 2: 1-5  
DSP Hanning Window, Part 3: 2-38  
DSP IIR Filter, Part 3: 2-39 to 2-40  
DSP Impulse Pattern, Part 3: 2-41  
DSP Impulse Train Pattern, Part 3: 2-42  
DSP Index Memory, Part 3: 2-43  
DSP Init Memory, Part 3: 2-44  
DSP Integral, Part 3: 2-45  
DSP Handle Clusters, Part 2: 1-2 to 1-4  
examples of DSP Handle Cluster allocation,  
Part 2: 1-4  
freeing buffers, Part 2: 1-4  
hexadecimal encoding of DSP Handle,  
Part 2: 1-3  
lower-level routines for customized DSP  
routines, Part 4: 2-3  
VIs for memory management and data transfer,  
Part 2: 1-2  
memory management VIs  
Copy Mem(DSP to DSP), Part 3: 2-1  
Copy Mem(DSP to LV), Part 3: 2-2  
Copy Mem(LV to DSP), Part 3: 2-3  
DSP Allocate Memory, Part 3: 2-6  
DSP Free Memory, Part 3: 2-34  
DSP Index Memory, Part 3: 2-43  
DSP Init Memory, Part 3: 2-44  
list of functions, Part 3: 1-2  
prototypes for customizable functions,  
Part 4: 3-2 to 3-3  
DSP Inv Chebyshev Coeff, Part 3: 2-46 to 2-47  
DSP Inverse FFT, Part 3: 2-47  
memory map files, Part 4: 2-7  
MLUT. See Memory Look Up Table (MLUT).  
DSP Inverse FHT, Part 3: 2-48  
DSP Kaiser-Bessel Window, Part 3: 2-49  
DSP Linear Evaluation, Part 3: 2-50  
DSP Load, Part 3: 2-50  
DSP Log, Part 3: 2-51  
DSP Max & Min, Part 3: 2-52  
N
DSP Median Filter, Part 3: 2-53  
DSP Multiply, Part 3: 2-54  
DSP Parks McClellan, Part 3: 2-55 to 2-57  
DSP Polynomial Evaluation, Part 3: 2-58  
DSP Power Spectrum, Part 3: 2-59  
DSP Product, Part 3: 2-59  
DSP Pulse Pattern, Part 3: 2-60  
DSP Ramp Pattern, Part 3: 2-61  
DSP Random Pattern, Part 3: 2-62  
DSP ReFFT, Part 3: 2-63  
NI-DAQ for DOS/Windows/LabWindows  
software, xv  
NI-DSP Analysis VIs  
accessing, Part 3: 1-3 to 1-4  
array VIs, Part 3: 1-2  
Copy Mem(DSP to DSP), Part 3: 2-1  
Copy Mem(DSP to LV), Part 3: 2-2  
Copy Mem(LV to DSP), Part 3: 2-3  
definition, xi  
DSP Absolute, Part 3: 2-4  
NI-DSP SRM for LabVIEW for Windows  
Index-4  
© National Instruments Corporation  
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Index  
DSP Reset, Part 3: 2-63  
DSP Reverse, Part 3: 2-64  
DSP Sawtooth Pattern, Part 3: 2-65  
DSP Set, Part 3: 2-66  
overview, Part 1: 1-1  
VI library files, Part 3: 1-3  
NI-DSP Interface Utilities  
creating custom DSP library, Part 4: 2-1 to 2-8  
adding function names to library function  
list file, Part 4: 2-4 to 2-5  
DSP Shift, Part 3: 2-66  
DSP Sinc Pattern, Part 3: 2-67  
DSP Sine Pattern, Part 3: 2-68  
DSP Sort, Part 3: 2-71  
adding object filenames to linker file (ifile),  
Part 4: 2-4  
DSP Square Pattern, Part 3: 2-69  
DSP Square Root, Part 3: 2-70  
DSP Start, Part 3: 2-72  
DSP Subset, Part 3: 2-72  
DSP Subtract, Part 3: 2-73  
DSP Sum, Part 3: 2-73  
DSP Timeout, Part 3: 2-74  
assembling source code, Part 4: 2-4  
compiling, assembling, and linking,  
Part 4: 2-7 to 2-8  
compiling source code, Part 4: 2-4  
creating source code, Part 4: 2-1 to 2-3  
deleting functions from NIDSP.fnc,  
Part 4: 2-5  
DSP Triangle Pattern, Part 3: 2-75 to 2-76  
DSP Triangular Train, Part 3: 2-77  
DSP Triangular Window, Part 3: 2-78  
DSP Uniform White Noise, Part 3: 2-79  
DSP Unwrap Phase, Part 3: 2-80  
DSP Zero Padder, Part 3: 2-81  
error handling, Part 2: 1-5 to 1-7  
examples, Part 2: 1-8 to 1-9  
files required to build example library,  
Part 4: 2-7  
generating assembly dispatch file,  
Part 4: 2-6  
GMaxMin.c example, Part 4: 2-1 to 2-2  
guidelines for custom functions,  
Part 4: 2-2 to 2-3  
including error codes, Part 4: 2-2  
makelib.bat file, Part 4: 2-8  
memory management, Part 4: 2-3  
parameter guidelines, Part 4: 2-2  
prototypes for customizable functions,  
Part 4: 3-1 to 3-3  
Fast Fourier Transform (FFT), Part 3: 1-4 to 1-5  
filtering, Part 3: 1-5 to 1-6  
filters, Part 3: 1-2  
frequency domain VIs, Part 3: 1-1  
function groups, Part 3: 1-1 to 1-3  
hints for improving execution speed, Part 2: 1-7  
LabVIEW .LLB files, Part 3: 1-3  
memory management VIs, Part 3: 1-2  
overview, Part 1: 1-1, Part 3: 1-1  
prototypes for customizable functions,  
Part 4: 3-1 to 3-3  
steps for creating, Part 4: 2-1  
using WE DSP32C assembler,  
Part 4: 2-3 to 2-4  
definition, xi  
installation, Part 4: 1-2  
interface layers to onboard functions, Part 4: 1-2  
LabVIEW interface, creating, Part 4: 2-8 to 2-12  
bundling input parameters to arrays,  
Part 4: 2-8 to 2-9  
signal VIs, Part 3: 1-1  
special features, Part 2: 1-5 to 1-7  
time domain VIs, Part 3: 1-1  
using in LabVIEW, Part 2: 1-1  
utility VIs, Part 3: 1-3  
calling Custom VI, Part 4: 2-10  
executing custom function from LabVIEW,  
Part 4: 2-12  
window VIs, Part 3: 1-2  
windowing, Part 3: 1-6 to 1-8  
Z in, Z out naming convention, Part 2: 1-5  
NI-DSP for LabVIEW for Windows. See also  
software.  
indexing output arrays to obtain results,  
Part 4: 2-10 to 2-12  
overview, Part 4: 1-1 to 1-2  
using, Part 4: 1-2  
board configuration  
NI-DSP software. See NI-DSP for LabVIEW for  
Windows.  
!NIC1100.CFG configuration file, Part 1: 1-3  
NIDSP.fnc file  
adding new function names, Part 4: 2-4 to 2-5  
deleting (replacing) function names, Part 4: 2-5  
NIDSPLNK file  
EISA bus computer, Part 1: 1-3  
ISA (or AT) bus computer, Part 1: 1-3  
contents of distribution diskettes, Part 1: 1-2  
development paths, Part 1: 1-1  
installation, Part 1: 1-2 to 1-3  
LabVIEW interface, creating, Part 4: 2-8 to 2-12  
bundling input parameters to arrays,  
Part 4: 2-8 to 2-9  
adding object filenames, Part 4: 2-4  
modifying, Part 4: 2-4  
calling Custom VI, Part 4: 2-10  
executing custom function from LabVIEW,  
Part 4: 2-12  
indexing output arrays to obtain results,  
Part 4: 2-10 to 2-12  
© National Instruments Corporation  
Index-5  
NI-DSP SRM for LabVIEW for Windows  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Index  
DSP Deconvolution, Part 3: 2-18  
DSP Derivative, Part 3: 2-19  
DSP Integral, Part 3: 2-45  
list of functions, Part 3: 1-1  
prototypes for customizable functions,  
Part 4: 3-2  
O
object filenames, adding to linker file, Part 4: 2-4  
output arrays, indexing, Part 4: 2-10 to 2-12  
output data buffers, Part 2: 1-5  
P
U
parameters  
utility VIs  
DSP Custom, Part 3: 2-16  
creating LabVIEW interface, Part 4: 2-8 to 2-9  
guidelines for custom functions, Part 4: 2-2  
prototypes for customizable functions,  
Part 4: 3-1 to 3-3  
DSP Handle to Address, Part 3: 2-38  
DSP Load, Part 3: 2-50  
DSP Reset, Part 3: 2-63  
DSP Start, Part 3: 2-72  
DSP Timeout, Part 3: 2-74  
R
DSP DMA Copy(DSP to LV), Part 4: 4-3  
DSP DMA Copy(LV to DSP), Part 4: 4-4  
list of functions, Part 3: 1-3  
random number generation. See DSP Gaussian  
White Noise VI; DSP Uniform White  
Noise VI.  
V
S
VIs. See NI-DSP Analysis VIs.  
SETUP program, Part 1: 1-2 to 1-3, Part 4: 1-1  
signal truncation. See windowing.  
signal VIs  
W
DSP Gaussian White Noise, Part 3: 2-35  
DSP Impulse Pattern, Part 3: 2-41  
DSP Impulse Train Pattern, Part 3: 2-42  
DSP Pulse Pattern, Part 3: 2-60  
DSP Ramp Pattern, Part 3: 2-61  
DSP Random Pattern, Part 3: 2-62  
DSP Sawtooth Pattern, Part 3: 2-65  
DSP Sinc Pattern, Part 3: 2-67  
DSP Sine Pattern, Part 3: 2-68  
DSP Square Pattern, Part 3: 2-69  
DSP Triangle Pattern, Part 3: 2-75 to 2-76  
DSP Triangular Train, Part 3: 2-77  
DSP Uniform White Noise, Part 3: 2-79  
list of functions, Part 3: 1-1  
WDAQCONF.EXE utility, Part 1: 1-3, Part 4: 2-7  
window VIs  
DSP Blackman Harris Window, Part 3: 2-8  
DSP Blackman Window, Part 3: 2-7  
DSP Exact Blackman Window, Part 3: 2-30  
DSP Exponential Window, Part 3: 2-31  
DSP Flat Top Window, Part 3: 2-33  
DSP Force Window, Part 3: 2-34  
DSP General Cosine Window, Part 3: 2-36  
DSP Hamming Window, Part 3: 2-37  
DSP Hanning Window, Part 3: 2-38  
DSP Kaiser-Bessel Window, Part 3: 2-49  
DSP Triangular Window, Part 3: 2-78  
list of functions, Part 3: 1-2  
prototypes for customizable functions,  
Part 4: 3-1  
prototypes for customizable functions,  
Part 4: 3-2  
software. See also NI-DSP for LabVIEW for  
Windows.  
windowing, Part 3: 1-6 to 1-8  
Developer Toolkit, xv  
NI-DAQ for DOS/Windows/LabWindows, xv  
mainlobes, Part 3: 1-7  
sidelobes, Part 3: 1-7  
spectral leakage, Part 3: 1-7  
T
technical support, B-1  
time domain VIs  
DSP Convolution, Part 3: 2-13  
DSP Correlation, Part 3: 2-14  
DSP Decimate, Part 3: 2-17  
NI-DSP SRM for LabVIEW for Windows  
Index-6  
© National Instruments Corporation  
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