LabVIEW User Manual

• Publisher: National Instruments
• Year: 1998
• Tongue: English
• Leaves: 514
• Edition: January 1998 Edition
• Category: Library

✦ Table of Contents

LabVIEW User Manual
Support
Internet Support
Bulletin Board Support
Fax-on-Demand Support
Telephone Support (USA)
International Offices
National Instruments Corporate Headquarters
Important Information
Warranty
Copyright
Trademarks
WARNING REGARDING MEDICAL AND CLINICAL USE OF NATI...
Contents
About This Manual
Organization of This Manual
Part I, Introduction to G Programming
Part II, I/O Interfaces
Part III, Analysis
Part IV, Network and Interapplication Communicatio...
Part V, Advanced G Programming
Appendices, Glossary, and Index
Conventions Used in This Manual
Related Documentation
Customer Communication
Chapter 1 Introduction
What Is LabVIEW?
How Does LabVIEW Work?
G Programming
Organization of the LabVIEW System (Windows)
Startup Screen on Windows
Organization of the LabVIEW System (Macintosh)
Organization of the LabVIEW System (UNIX)
Toolkit Support
Where Should I Start?
Part I Introduction to G Programming
Chapter 2 Creating VIs
What is a Virtual Instrument?
How Do You Build a VI?
VI Hierarchy
Controls, Constants, and Indicators
Terminals
Wires
Tip Strips
Wire Stretching
Selecting and Deleting Wires
Bad Wires
VI Documentation
What is a SubVI?
Hierarchy Window
Search Hierarchy
Icon and Connector
Opening, Operating, and Changing SubVIs
How Do You Debug a VI?
Chapter 3 Loops and Charts
What is a Structure?
Charts
Chart Modes
Faster Chart Updates
Overlaid Versus Stacked Plots
While Loops
Mechanical Action of Boolean Switches
Timing
Preventing Code Execution in the First Iteration
Shift Registers
Using Uninitialized Shift Registers
For Loops
Numeric Conversion
Chapter 4 Case and Sequence Structures and the Formula Node
Case Structure
VI Logic
Sequence Structures
Modifying the Numeric Format
Setting the Data Range
Formula Node
Artificial Data Dependency
Chapter 5 Arrays, Clusters, and Graphs
Arrays
How Do You Create and Initialize Arrays?
Array Controls, Constants, and Indicators
AutoIndexing
Multiplot Graphs
Using Auto-Indexing to Set the For Loop Count
Using Array Functions
Build Array
Initialize Array
Array Size
Array Subset
Index Array
Efficient Memory Usage: Minimizing Data Copies
What is Polymorphism?
Clusters
Graphs
Customizing Graphs
Graph Cursors
Graph Axes
Data Acquisition Arrays
Intensity Plots
Chapter 6 Strings and File I/O
Strings
Creating String Controls and Indicators
Strings and File I/O
File I/O
File I/O Functions
Writing to a Spreadsheet File
Using the File I/O Functions
Specifying a File
Paths and Refnums
File I/O Examples
Datalog Files
Part II I/O Interfaces
Chapter 7 Getting Started with a LabVIEW Instrument Driver
What is a LabVIEW Instrument Driver?
Where Can I Get Instrument Drivers?
Where Should I Install My LabVIEW Instrument Drive...
How Do I Access the Instrument Driver VIs?
Instrument Driver Structure
Obtaining Help for Your Instrument Driver VIs
Running the Getting Started VI Interactively (Sele...
Interactively Testing Component VIs
Building Your Application
Related Topics
Open VISA Session Monitor VI
Error Handling
Testing Communication with Your Instrument
Developing a Quick and Simple LabVIEW InstrumentD...
Modifying an Existing Driver
Developing a Simple Driver
Developing a Full-Featured Driver
Using LabVIEW with IVI Instrument Drivers
Chapter 8 LabVIEW VISA Tutorial
What is VISA?
Supported Platforms and Environments
Why Use VISA?
VISA Is the Standard
Interface Independence
Platform Independence
Easily Adapted to the Future
Basic VISA Concepts
Default Resource Manager, Session, and Instrument ...
How Do I Search for Resources?
What is a VISA Class?
Popping Up on a VISA Control
Opening a Session
How Do the Default Resource Manager, Instrument De...
Closing a Session
When Is It a Good Idea to Leave a Session Open?
Error Handling with VISA
Easy VISA VIs
Message-Based Communication
How Do I Write To and Read From a Message-Based De...
Register-Based Communication (VXI only)
Basic Register Access
Basic Register Move
Low-Level Access Functions
Using VISA to Perform Low-Level Register Accesses
Bus Errors
Comparison of High-Level and Low-Level Access
Speed
Ease of Use
Accessing Multiple Address Spaces
VISA Properties
Serial
GPIB
VXI
VISA Property Examples
Serial Write and Read
How Do I Set a Termination Character foraReadOp...
VXI Properties
Events
GPIB SRQ Events
Trigger Events
Interrupt Events
Locking
Shared Locking
Platform-Specific Issues
Programming Considerations
Multiple Applications Using the NI-VISA Driver
Multiple Interface Support Issues
VXI and GPIB Platforms
Multiple GPIB-VXI Support
Serial Port Support
VME Support
Debugging A VISA Program
Debugging Tool for Windows 95/NT
VISAIC
Chapter 9 Introduction to LabVIEW GPIB Functions
Types of Messages
The Controller-In-Charge and System Controller
Compatible GPIB Hardware
LabVIEW for Windows 95 and Windows 95-Japanese
LabVIEW for Windows NT
LabVIEW for Windows 3.1
LabVIEW for Mac OS
LabVIEW for HP-UX
LabVIEW for Sun
LabVIEW for Concurrent PowerMAX
Chapter 10 Serial Port VIs
Handshaking Modes
Software Handshaking—XON/XOFF
Error Codes
Port Number
Windows 95 and 3.x
Macintosh
UNIX
Part III Analysis
Chapter 11 Introduction to Analysis in LabVIEW
The Importance of Data Analysis
Full Development System
Analysis VI Overview
Notation and Naming Conventions
Data Sampling
Sampling Signals
Sampling Considerations
Why Do You Need Anti-Aliasing Filters?
Why Use Decibels?
Chapter 12 Signal Generation
Normalized Frequency
Wave and Pattern VIs
Phase Control
Chapter 13 Digital Signal Processing
The Fast Fourier Transform (FFT)
DFT Calculation Example
Magnitude and Phase Information
Frequency Spacing between DFT/FFT Samples
Fast Fourier Transforms
Zero Padding
FFT VIs in the Analysis Library
Two-Sided FFT
One-Sided FFT
The Power Spectrum
Loss of Phase Information
Frequency Spacing between Samples
Summary
Chapter 14 Smoothing Windows
Introduction to Smoothing Windows
About Spectral Leakage and Smoothing Windows
Windowing Applications
Characteristics of Different Types of Window Funct...
Rectangular (None)
Hanning
Hamming
Kaiser-Bessel
Triangle
Flattop
Exponential
Windows for Spectral Analysis Versus Windows forC...
What Type of Window Do I Use?
Chapter 15 Spectrum Analysis and Measurement
Introduction to Measurement VIs
You Will Learn
Spectrum Analysis
Calculating the Amplitude and Phase Spectrum of a ...
Calculating the Frequency Response of a System
Harmonic Distortion
Total Harmonic Distortion
Using the Harmonic Analyzer VI
Summary
Chapter 16 Filtering
Introduction to Digital Filtering Functions
Ideal Filters
Practical (Nonideal) Filters
The Transition Band
Passband Ripple and Stopband Attenuation
IIR and FIR Filters
Filter Coefficients
Infinite Impulse Response Filters
Cascade Form IIR Filtering
Butterworth Filters
Chebyshev Filters
Chebyshev II or Inverse Chebyshev Filters
Elliptic (or Cauer) Filters
Bessel Filters
Finite Impulse Response Filters
Designing FIR Filters by Windowing
Designing Optimum FIR Filters Using the Parks-McCl...
Designing Narrowband FIR Filters
Windowed FIR Filters
Optimum FIR Filters
FIR Narrowband Filters
Nonlinear Filters
How Do I Decide Which Filter to Use?
Summary
Chapter 17 Curve Fitting
Introduction to Curve Fitting
Applications of Curve Fitting
General LS Linear Fit Theory
How to Use the General LS Linear Fit VI
Building the Observation Matrix
Nonlinear Lev-Mar Fit Theory
Using the Nonlinear Lev-Mar Fit VI
Chapter 18 Linear Algebra
Linear Systems and Matrix Analysis
Types of Matrices
Determinant of a Matrix
Transpose of a Matrix
Can You Obtain One Vector as a Linear Combination ...
How Can You Determine Linear Independence? (Matrix...
Magnitude” (Norms) of Matrices
Determining Singularity (Condition Number)
Basic Matrix Operations and Eigenvalues-Eigenvecto...
Dot Product and Outer Product
Eigenvalues and Eigenvectors
Matrix Inverse and Solving Systems of Linear Equat...
Solutions of Systems of Linear Equations
Matrix Factorization
Pseudoinverse
Summary
Chapter 19 Probability and Statistics
Probability and Statistics
Statistics
Mean
Median
Sample Variance
Standard Deviation
Mode
Moment About Mean
Histogram
Mean Square Error (MSE)
Root Mean Square (RMS)
Probability
Random Variables
Normal Distribution
Summary
Part IV Network and Interapplication Communication
Chapter 20 Introduction to Communication
LabVIEW Communication Overview
Introduction to Communication Protocols
File Sharing Versus Communication Protocols
Client/Server Model
A General Model for a Client
A General Model for a Server
Chapter 21 TCP and UDP
Overview
LabVIEW and TCP/IP
Internet Addresses
Internet Protocol (IP)
User Datagram Protocol (UDP)
Using UDP
Transmission Control Protocol (TCP)
Using TCP
TCP Versus UDP
TCP Client Example
Timeouts and Errors
TCP Server Example
TCP Server with Multiple Connections
Setup
UNIX
Macintosh
Windows 3.x
Windows 95 and Windows NT
Chapter 22 ActiveX Support
ActiveX Automation Server Functionality
ActiveX Server Properties and Methods
ActiveX Automation Client Functionality
ActiveX Client Examples
Converting ActiveX Variant Data to G Data
Adding a Workbook to Microsoft Excel from LabVIEW
Chapter 23 Using DDE
DDE Overview
Services, Topics, and Data Items
Examples of Client Communication with Excel
LabVIEW VIs as DDE Servers
Requesting Data Versus Advising Data
Synchronization of Data
Networked DDE
Using NetDDE
Chapter 24 AppleEvents
AppleEvents
Sending AppleEvents
Client Server Model
AppleEvent Client Examples
Launching Other Applications
Sending Events to Other Applications
Dynamically Loading and Running a VI
Chapter 25 Program-to-Program Communication
Introduction to PPC
Ports, Target IDs, and Sessions
PPC Client Example
PPC Server Example
PPC Server with Multiple Connections
Part V Advanced G Programming
Chapter 26 Customizing VIs
How Do You Customize a VI?
Set Window Options
SubVI Node Setup
Chapter 27 Front Panel Object Attributes
Chapter 28 Program Design
Use Top-Down Design
Make a List of User Requirements
Design the VI Hierarchy
Create the Program
Plan Ahead with Connector Panes
SubVIs with Required Inputs
Good Diagram Style
Watch for Common Operations
Use Left-to-Right Layouts
Check for Errors
Watch Out for Missing Dependencies
Avoid Overuse of Sequence Structures
Study the Examples
Chapter 29 Where to Go from Here
Other Useful Resources
Solution Wizard and Search Examples
Data Acquisition Applications
G Programming Techniques
Function and VI Reference
Resources for Advanced Topics
Attribute Nodes
VI Setup and Preferences
Local and Global Variables
Creating SubVIs
VI Profiles
Control Editor
List and Ring Controls
Call Library Function
Code Interface Nodes
Appendix A Analysis References
Appendix B Common Questions
Communications Common Questions
Questions for All Platforms
Windows Only
Macintosh Only
GPIB
All Platforms
Windows Only
Serial I/O
All Platforms
Windows Only
Sun Only
Appendix C Customer Communication
Electronic Services
Telephone and Fax Support
Technical Support Form
LabVIEW Hardware and Software ConfigurationForm
National Instruments Products
Other Products
Documentation Comment Form
Glossary
Numbers/Symbols
A
B
C
D
E-F
G
H-I
L-M
N-O
P-R
S
T
U-V
W
Index
A
B
C
D
E-F
G
H
I
J-L
M
N-P
Q
R-S
T
U-V
W
X-Z
Figures
Figure 11-1. Analog Signal and Corresponding Sampl...
Figure 11-2. Aliasing Effects of an Improper Sampl...
Figure 11-3. Actual Signal Frequency Components
Figure 11-4. Signal Frequency Components and Alias...
Figure 11-5. Effects of Sampling at Different Rate...
Figure 14-1. Periodic Waveform Created from Sample...
Figure 14-2. Sine Wave and Corresponding Fourier T...
Figure 14-3. Spectral Representation When Sampling...
Figure 14-4. Time Signal Windowed Using a Hamming ...
Figure 22-1. Preferences Dialog Box, Server Config...
Figure 22-2. Block Diagram Displaying ActiveX Vari...
Figure 22-3. Adding a Workbook to Microsoft Excel
Figure 25-1. PPC VI Execution Order (Used by Permi...
Tables
Table 22-1. Functions for ActiveX Automation Clien...
Table 23-1. Values to Add in Place of Default
Activities
Activity 2-1. Create a VI
Activity 2-2. Document a VI
Activity 2-3. Create an Icon and Connector
Activity 2-4. Call a SubVI
Activity 2-5. Debug a VI in LabVIEW
Activity 3-1. Experiment with Chart Modes
Activity 3-2. Use a While Loop and a Chart
Activity 3-3. Change the Mechanical Action of a Boolean Switch
Activity 3-4. Control Loop Timing
Activity 3-5. Use a Shift Register
Activity 3-6. Create a Multiplot Chart
Activity 3-7. Use a For Loop
Activity 4-1. Use the Case Structure
Activity 4-2. Use a Sequence Structure
Activity 4-3. Use the Formula Node
Activity 5-1. Create an Array with Auto-Indexing
Activity 5-2. Use Auto-Indexing on Input Arrays
Activity 5-3. Use the Build Array Function
Activity 5-4. Use the Graph and Analysis VIs
Activity 6-1. Concatenate a String
Activity 6-2. Use Format Strings
Activity 6-3. String Subsets and Number Extraction
Activity 6-4. Write to a Spreadsheet File
Activity 6-5. Append Data to a File
Activity 6-6. Read Data from a File
Activity 12-1. Learn More about Normalized Frequency
Activity 12-2. Use the Sine Wave and Sine Pattern VIs
Activity 12-3. Build a Function Generator
Activity 13-1. Use the Real FFT VI
Activity 14-1. Compare a Windowed and Nonwindowed Signal
Activity 15-1. Use the Amplitude and Phase Spectrum VI
Activity 15-2. Compute the Frequency and Impulse Response
Activity 15-3. Calculate Harmonic Distortion
Activity 16-1. Extract a Sine Wave
Activity 17-1. Use the Curve Fitting VIs
Activity 17-2. Use the General LS Linear Fit VI
Activity 17-3. Use the Nonlinear Lev-Mar Fit VI
Activity 18-1. Compute the Inverse of a Matrix
Activity 18-2. Solve a System of Linear Equations
Activity 19-1. Use the Normal Distribution VI
Activity 26-1. Use Setup Options for a SubVI
Activity 27-1. Use an Attribute Node