Overview

Structures, an important type of node, govern execution flow in a VI, just as control structures do in a standard programming language. This chapter introduces you to the main structures in LabVIEW: the While Loop, the For Loop, the Case Structure, and the Sequence Structure, and then shows you how to combine the While Loop with the Case Structure into a powerful application framework. You will also learn how to implement lengthy formulas using the Formula Node and simple formulas with the Expression Node, how to pop up a dialog box containing your very own message, and a few basics on how to control the timing of your programs, as well as how the Timed Structures provide advanced timing and synchronization. You might want to take a look at some examples of structures in EXAMPLES\GENERAL\STRUCTS.LLB in LabVIEW.

Goals

• Know the uses of the While Loop and the For Loop and understand the differences between them

• Recognize the necessity of shift registers in graphical programming

• Understand the different types of Case Structuresnumeric, string, and Boolean

• Learn how to regulate execution order using Sequence Structures

• Understand the dangers of the Stacked Sequence Structure and Sequence Locals

• Use the Formula Node to implement long mathematical formulas

• Make LabVIEW pop up a dialog box that says anything you tell it to

• Understand how to use some of LabVIEW's simple timing functions

• Use the Expression Node to implement formulas with only one variable

• Understand how the Timed Structures and VIs allow Timed Loops and Timed Sequences to be synchronized

• Learn how to combine the While Loop with the Case Structure to build simple, yet powerful and scalable, application frameworks