Configure the Express VI:

To properly configure the Express VI you must first select how you are making the connection from the SensorDAQ analog out terminal to the Power Amplifier. It is recommended to make this connection via a BTA cable. The BTA cable input amplifies the signal from the SensorDAQ by a power of 2. The SensorDAQ analog output can supply output in a range from 0 to 5 volts. This means that the power amplifier will be supplying in a range from 0 to 10 volts. You can review the Power Amplfier User Manual for more detail on making the connection.

The other configuration choice is how the Express VI will be used in your LabVIEW program. If your program requires that you periodically change the output, then you should select Continuously Change Output Voltage. This would be the selection to make if you are placing the Express VI within a loop. Note that when you make this selection, the Express VI will include an input terminal called Stop and an output terminal called Stopped. You must stop the Express VI prior to stopping the loop. The best way to do this is to wire in a front panel Stop button into the Stop input terminal and wire the output from the Stopped output terminal to the While Loop’s conditional terminal (this wiring sequence stops the Express VI and then the loop).

The other programming option is to Set to a Single Output Voltage. This selection would be used if you are simply setting the output to a single value, and holding that value during the program. With this selection you should not call the Express VI more than one time (do not place the Express VI within a loop). But note that you might have to make a second copy of the Express VI for the end of your program, to reset the output to 0 volts. Otherwise, the output may remain on, even after your program ends.

Test the Hardware:

When the Express VI is open, you can press the Run button to test your hardware before integrating the Express VI into the LabVIEW block diagram.

Placing the Express VI in LabVIEW:

After configuring the Express VI click on the OK button. Closing the Express popup will send you back to the Block Diagram of LabVIEW for developing your program.

It is important to understand that if the Express VI shows an input terminal called “stop (F)” and an output terminal called “stopped”, this means that the Express VI should be placed within a loop, and that the Express VI should be terminated prior to terminating the loop.

To accomplish this, wire a Boolean control (such as a front panel stop button) into the stop (F) terminal and wire the stopped terminal output into the While Loops’ conditional terminal. Note that an easy way to create the Front Panel stop control is to right click on the stop (F) terminal and select Create>Control from the menu.