LabVIEW Advanced Programming Techniques

Transcription

1 LabVIEW Advanced Programming Techniques SECOND EDITION Rick Bitter Motorola, Schaumburg, Illinois Taqi Mohiuddin MindspeedTechnologies, Lisle, Illinois Matt Nawrocki Motorola, Schaumburg, CRC Press Taylor &. Francis Group Boca Raton London New York CRC Press is an imprint of the Taylor & Francis Group, an informa business

2 Contents Chapter 1 Introduction to Lab VIEW Virtual Instruments The Front Panel Block Diagram Executing Vis LabVIEW File Extensions LabVIEW Projects Help Built-inHelp Websites Data Flow Programming Menüs and Palettes Front Panel Controls User Control Sets Numeric Boolean String & Path Ring & Enum, List & Table Array, Cluster, and Matrix Graphs and Charts String & Path and I/O Block Diagram Functions Structures Sequence Structure Case Structure For Loop WhileLoop Event Structure Disable Structure Timed Structure FormulaNode Numeric, Boolean, String, and Comparison Array and Cluster Timing Dialog and User Interface File I/O Instrument I/O, Connectivity, and Communication Creating Connectors Editing Icons 54

3 UsingSubVIs VI Setup Setting Options Paths Block Diagram Environment Revision History VI Server and Web Server Controls/Functions Palettes 65 Chapter 2 LabVIEW Features Global and Local Variables Shared Variables Customizing Controls Custom Controls Type Definitions Strict Type Definitions Property Nodes Reentrant Vis Libraries (.LLB) Web Server Web Publishing Tool Instrument Driver Tools Profile Functions VI Profiler Buffer Allocations VIMetrics Auto SubVI Creation Graphical Comparison Tools Compare Vis Compare VI Hierarchies SCC Compare Files Report Generation Palette Application Builder Sound Vis Application Control VI Server Vis Menü Vis Help Vis Other Application Control Vis Advanced Functions Data Manipulation Calling External Code Synchronization 119

4 2.18 Source Code Control Configuration Adding and Modifying Files Advanced Features Graphs Standard Graphs D Graphs Digital and Mixed Signal Graphs Picture Graphs Data Logging Find and Replace Print Documentation VI History Key Navigation Express Vis Navigation Window Splitter Bar 133 Bibliography 134 Chapter 3 State Machines Introduction State Machines in LabVIEW When to Use a State Machine Types of State Machines Enumerated Types and Type Definitions Type Definitions Used with State Machines Creating Enumerated Constants and Type Definitions Converting between Enumerated Types and Strings Drawbacks to Using Type Definitions and Enumerated Controls Sequence-Style State Machine When to Use a Sequence-Style State Machine Example Test Executive-Style State Machine The LabVIEW Template Standard State Machine When to Use a Test Executive-Style State Machine Recommended States for a Test Executive-Style State Machine Determining States for Test Executive-Style State Machines Example Classical-Style State Machine When to Use a Classical-Style State Machine Example Queued-Style State Machine When to Use the Queued-Style State Machine 162

5 3.6.2 Example Using Lab VIEW Queue Functions Example Using an Input Array Drawbacks to Using State Machines Recommendations and Suggestions Documentation Ensure Proper Setup Error, Open, and Close States Status of Shift Registers Typecasting an Index to an Enumerated Type Make Sure You Have a Way Out Problems/Examples The Blackjack Example The Test Sequencer Example The PC Calculator Example 176 Bibliography 179 Chapter 4 Application Structure Planning Purpose of Structure Software Models The Waterfall Model The Spiral Model Block Diagrams Description of Logic Project Administration Documentation LabVIEW Documentation Printing LabVIEW Documentation VI History The Three-Tiered Structure Main Level User Interface User Interface Design Property Node Examples Customizing Menüs Exception-Handling at the Main Level Second Level Test Level Bottom Level Drivers Style Tips Sequence Structures Nested Structures Drivers PollingLoops Array Handling 206

6 4.11 The Lab VIEW Project Project Overview Project File Operations Project Library Project File Organization Build Specifications Source Code Management Summary 215 Bibliography 218 Chapter 5 Drivers Communication Standards GPIB Serial Communications VXI LXI VISA Definition DDE OLE TCP/IP DataSocket Traditional DAQ NI-DAQmx File I/O Code Interface Node and Call Library Function Driver Classifications Configuration Drivers Measurement Drivers Status Drivers Inputs/Outputs Error Handling NISpy NISpy Introduction Configuring NI Spy RunningNI Spy Driver Guidelines Reuse and Development Reduction Driver Example Instrument I/O Assistant IVI Drivers Classes of IVI Drivers Interchangeability Simulation State Management IVI Driver Installation 253

7 IVI Configuration How to Use IVI Drivers Soft Panels IVI Driver Example 256 Bibliography 260 Chapter 6 Exception Handling Exception Handling Defined Types of Errors I/O Errors Logical Errors Built-in Error Handling Error Cluster Error Codes VISA Error Handling Simple Error Handler General Error Handler Find First Error Clear Error Performing Exception Handling When? Exception-Handling at Main Level Programmer-Defmed Errors Managing Errors State Machine Exception Handling Logging Errors External Error Handler Proper Exit Procedure Exception Handling Example Debugging Code Error List Execution Highlighting Single-Stepping Probe Tool Breakpoint Tool Suspending Execution Data Logging NISpy/GPIB Spy Utilization of Debugging Tools Evaluating Race Conditions Summary 296 Bibliography 297

8 Chapter 7 Shared Variable Overview of Shared Variables Single Process Variables Network Published Variable Shared Variable Engine Accessing the Shared Variable Engine Shared Variable Manager Windows Event Viewer Windows Performance Monitor Windows Task Manager Shared Variable Processes and Services Shared Variable Networking Shared Variable Domains Pitfalls of Distributed Applications Shared Variables and Network Security LabVIEW Specific Security Issues 316 Bibliography 317 Chapter 8.NET, ActiveX, and COM Introduction to OLE, COM, and ActiveX Definition of Related Terms Properties and Methods Interfaces Clients and Servers In-Process and Out-of-Process TheVariant COM OLE ActiveX Description of ActiveX ActiveX Definitions ActiveX Technologies ActiveX Terminology Events Containers How ActiveX Controls Are Used NET Descriptionof.NET Common Language Runtime Intermediate Language WebProtocols Assembly Global Assembly Cache 329

9 8.6 Lab VIEW and ActiveX The Lab VIEW ActiveX Container Embedding Objects Inserting ActiveX Controls and Documents The ActiveX Palette Automation Open and Close The Property Node The Invoke Node Variant to Data Function Using the Container versus Automation Event Support in LabVIEW Register Event Event Callback LabVIEW as ActiveX Server LabVIEW and.net NET Containers NET Palette The VI Server ActiveX and.net Examples Common Dialog Control Progress Bar Control Microsoft Calendar Control Web Browser Control Microsoft Scripting Control Microsoft System Information Control Microsoft Status Bar Control Microsoft Tree View Control Microsoft Agent Request Objects First Tier Other First-Tier Controls The Characters Object The Character Control Registry Editing Control Controlling Microsoft Word Microsoft Access Control Instrument Control Using ActiveX Instrument Control Using.NET Controlling LabVIEW from Other Applications Understanding ActiveX Error Codes Advanced ActiveX details 393 Bibliography 395 Chapter 9 Multithreading in LabVIEW Multithreading Terminology Win32 398

10 9.1.2 UNIX Multitasking Preemptive Multithreading Kernel Objects Thread Process Application Priority How Operating Systems Determine which Threads Security Thread Safe Thread Mechanics Thread States Scheduling Threads Context Switching Win32 Multithreading Pthreads Multithreading Problems Race Conditions Priority Inversion Starvation Deadlocking Operating System Solutions Multithreading Myths The More Threads, the Merrier More Threads, More Speed Makes Applications More Robust Conclusion on Myths Hyper-Threading Multithreaded Lab VIEW Execution Subsystems The Run Queue DLLs in Multithreaded LabVIEW Customizing the Thread Connguration Thread Count Estimation for LabVIEW Same as Caller or Single Subsystem Applications Multiple Subsystem Applications Optimizing Vis for Threading Using VI Priorities Subroutines in LabVIEW Express Vis LabVIEW Data Types When to Use Subroutines Summary 441 Bibliography 441

11 Chapter 10 Object-Oriented Programming in Lab VIEW What Is Object-Oriented? TheClass Encapsulation Aggregation Inheritance Polymorphism Objects and Classes Methods Special Method Constructor Special Method Destructor Properties Object Analysis Object Design Container Classes Abstract Classes Object Programming Developing Objects in Lab VIEW Properties Constructors Destructors Methods Public Methods Private Methods Examples in Developing Instrument Drivers Complex Instrument Designs Object Template Exercises 489 Bibliography 489 Index 491