labvie第二次课.ppt

Summary Initializing Shift Registers Case Structure Modifying Numeric Controls Indicators 上机 本周五，第三大节，C机房 任务1. 习题3－1 2. 求500个随机数中的最大值和最小值 3. 习题3－2 4. 在习题3－2中加 event 下周一，第二大节，C机房 任务 1. 3－3 2. 3－4 3. 3－5 4. 设计一简单的信号源，要求能选择正弦、三角和方波，并用Waveform Graph显示 2: The Case structure allows you to choose a course of action depending on an input value. In the Structures subpalette of the Controls palette. Analogous to a case statement in Pascal or if-then-else statement in other languages. Like a deck of cards. You can see only one case at a time. Customers often think that when separate cases are shown, it means to create two or more case structures. Stress that you need only one case structure. Explain examples: Example 1: Boolean input: Simple if-then case. If the Boolean input is TRUE, the true case will execute; otherwise the FALSE case will execute. Example 2: Numeric input. The input value determines which box to execute. If out of range of the cases, LabVIEW will choose the default case. Example 3: String input. Briefly discuss the string input for cases. Pages 6-3 to 6-5: Discuss the examples on the slide. Be sure to mention the difference between the numeric and Boolean Case structures. Also, remind the students that all cases must provide a value for all output tunnels. Demonstrate using the Text Ring from the List Ring subpalette of the Controls palette. Demonstrate some of the features of Case structures: Directly typing into the Cases Setting ranges in the Case Reordering the Cases The Default Case 11: In a text-based language, program statements execute in the order in which they appear. In data flow, a node executes when data is available at all its input terminals. Sometimes it is hard to tell the exact order of execution. Often, certain events must take place b