《NI官方labview培训教材Lesson 5-8》.pptVIP

Lesson 5Clusters TOPICS Introduction to Clusters Cluster Functions Error Clusters Clusters Data structure that groups data together Data may be of different types Analogous to struct in C or a record in Pascal Elements must be either all controls or all indicators Thought of as wires bundled into a cable Cluster Controls and Indicators Creating Cluster Constants Cluster Order Elements have a logical order (start with 0) To change order, right-click the border and select Reorder Controls in Cluster... Using Clusters to Pass Data to SubVIs Use clusters to pass several values to one terminal Overcomes 28-terminal limit Simplifies wiring Cluster Functions - Bundle Cluster Functions - Unbundle Error Cluster Error Cluster Details Status is a Boolean value that reports TRUE if an error occurred. Most VIs, functions, and structures that accept Boolean data also recognize this parameter. Code is a signed 32-bit integer that identifies the error numerically. A non-zero error code coupled with a status of FALSE signals a warning rather than a fatal error. Source is a string that identifies where the error occurred. Error Handling with Clusters LabVIEW does not handle errors automatically. In LabVIEW, you can make these error handling decisions on the block diagram of the VI. Error handling in LabVIEW follows the dataflow model. Just as data flow through a VI, so can error information. Wire the error information from the beginning of the VI to the end. Simple Error Handler Use the Simple Error Handler to handle the error at the end of the execution flow. The Simple Error Handler is located on the Functions?All Functions?Time and Dialog palette. Wire the error cluster to the Error In (no error) input. Using While Loops for Error Handling Lesson 6Plotting Data TOPICS Waveform Charts Waveform and XY Graphs Intensity Graphs Wiring to Charts Modifying Chart Properties Customizing Charts and Graphs Right-click and select Visible Items to view the following items: Plot Lege