Question

It's a labview question. Block diagram picture please.

Eliminating Case structure errors. E5.4 Using a sing le While Loop, construct a VI that executes loop N times or until the user presses stop button. Be sure to include the Time Delay Express VI so the user has time to press the Stop button.

Answer 1

Step -1 Open a new blank VI by selecting File» New VI

Step -2 To display a temporary version of the palette right-click any blank space on the block diagram if the Functions palette is not visible. Click the thumbtack in the upper left corner of the Functions palette to pin the palette so it is no longer temporary.

Step -3 Select the while loop from the Structures palette under the Functions palette.

Step -4 Use the cursor to drag a selection rectangle around the section of the block diagram you want to repeat.

Functions Search View Programming LStructures number (0 to 1) 123 DBL eigi UAR LOCALGLOB

Step -5 A while loop boundary encloses the section you have selected when you release the mouse button,

number (0 to 1) D123 DEL

Step -6 To place a Stop button on the front panel go to Controls Palette» Boolean» Stop.

Step -7. Add the Stop button from the block diagram to the while loop by dragging and dropping it inside the while loop.

number (0 to 1) 1.23 DBL stop STOP TFL

Step -8 The conditional terminal, shown below, defines when the loop stops. There are two settings for the conditional terminal: Continue if True and Stop if True. When set to Continue if True, the while loop runs only if a Boolean value of true is sent to the terminal. If the conditional terminal is set to Stop if True, and a Boolean value of true is sent to the conditional terminal, the loop halts execution.

Stop if True

Continue if True

Step -9 To switch the conditional terminal between Continue if True and Stop if True, right-click on the conditional terminal and check the corresponding setting.

Step -10 Wire the Stop button to the conditional terminal so that you can control the execution of the while loop. When the Stop button is pressed, a true value is passed to the conditional terminal causing the while loop to stop the execution. You can wire any Boolean data to the conditional terminal to control the execution of a while loop.

Step -11 The iteration terminal is an output terminal that contains the number of completed iterations. The iteration count always starts at zero. During the first iteration, the iteration terminal returns 0.

Step -12 This is a simple while loop that generates random numbers and displays them until the Stop button is pressed.