National Instruments BridgeVIEW 用户手册

Chapter 11

Loops and Charts

11-6

© National Instruments Corporation

8.

Rescale the knob. Using the Labeling tool, double-click on 

10.0

 in the 

scale around the knob, and replace it with 

2.0

. 

Block Diagram

9.

Open the block diagram and create the diagram in the following 
illustration.

a.

Place the While Loop in the block diagram by selecting it from 
Functions»Structures. The While Loop is a resizable box that is 
not dropped on the diagram immediately. Instead, you have the 
chance to position and resize it. To do so, click in an area above 
and to the left of all the terminals. Continue holding down the 
mouse button and drag out a rectangle that encompasses the 
terminals. 

b.

Select the Random Number (0–1) function from Functions» 
Numeric.

c.

Wire the diagram as shown in the Block Diagram, connecting the 
Random Number (0–1) function to the Random Signal chart 
terminal, and the Enable switch to the conditional terminal of the 
While Loop. Leave the Loop Delay terminal unwired for now.

10. Return to the front panel and turn on the vertical switch by clicking on 

it with the Operating tool. 

11. Save the VI as 

Random Signal.vi

 in the 

BridgeVIEW\Activity

 

directory. 

12. Run the VI.

The While Loop is an indefinite looping structure. The diagram within it 
executes as long as the specified condition is TRUE. In this example, as 
long as the switch is on (TRUE), the diagram continues to generate random 
numbers and display them on the chart.