The user programmable button on the left-hand side of the NI ELVIS III workstation serves two purposes. It aids in connecting the NI ELVIS III to your host computer, and you can programmatically monitor it in a LabVIEW RT or LabVIEW FPGA application.
Pressing and holding the button enables the OLED display, which shows the current device ID and IP addresses for the NI ELVIS III. This functionality is always active, even if an application is programmatically monitoring the button.
You can also programmatically monitor the button in your application to trigger or control other events. You can acquire the values from the button by using the Button Express VI in an RT application or by using the FPGA I/O node in an FPGA application.
The following figure shows an example of using the Button Express VI, which is highlighted, to monitor the button and display the current state using a Boolean indicator. When you press the button, the Boolean indicator of the VI returns TRUE.
Take care when you press and hold the user programmable button to display the device ID and IP addresses. If a running VI is monitoring the button, it cannot differentiate between a button press intended to enable the display and a press intended to trigger an action by the application. Pressing and holding the button enables the display and triggers the programmatic action simultaneously.