National Instruments BridgeVIEW End of Activity 12-1.

Chapter 12 Case and Sequence Structures and the Formula Node

BridgeVIEW User Manual 12-4 © National Instruments Corporation

One Button Dialog function (Functions»Time & Dialog)—In this

activity, the function displays a dialog box that contains the message

Error...Negative Number.

String Constant (Functions»String)—Enter text inside the box with

the Labeling tool.

The VI executes either the TRUE case or the FALSE case. If the

number is greater than or equal to zero, the VI executes the TRUE case

and returns the square root of the number. The FALSE case outputs

–99999.00 and displays a dialog box with the message

Error...Negative Number.

Note You must define the output tunnel for each case. When you create an output

tunnel in one case, tunnels appear at the same position in all the other cases.

Unwired tunnels appear as white squares.

4. Return to the front panel and run the VI. Try a number greater than zero

and a number less than zero by changing the value in the digital control

you labeled Number. Notice that when you change the digital control

to a negative number, BridgeVIEW displays the error message you set

up in the FALSE case of the Case structure.

5. Save the VI as Square Root.vi in the BridgeVIEW\Activity

directory.

The block diagram in this activity has the same effect as the following

pseudocode in a text-based language.

if (Number >= 0) then

Square Root Value = SQRT(Number)

else

Square Root Value = -99999.00

Display Message "Error...Negative Number"

end if

End of Activity 12-1.