indicators (graphs) in a VI running on real time

[abdel2]

I thought you couldn't created any indicators or controls in a VI that runs on a real-time OS. Why is it that I can put an indicator (eg: graph) in the VI, run in on RT target, and still be able to see the graph being updated? How is it doing this internally?

[StevenA]

abdel2, when you target a vi to run on RT target from the LabVIEW development environment.  Labview automatically sets up what is referred to as the default communication.  LabVIEW default communication updates the front panel on your vi just as if it were running locally.  This is intended for development and debug, a very useful and powerful feature of labview RT.   When you run your vi on the RT target without running it from the development environment or your you start the vi from the development environment then disconnect from the RT target, the vi will continue to run without the default communication and front panel controls and indicators are meaningless.

[NI-Bob]

Hello Abdel2,

Thank you for contacting National Instruments!  It is true that with a Real-Time controller you do not want to use controls and indicators as you would in a typical LabVIEW program.  However, for debugging purposes you can open the VI that is on the Real-Time Controller on your development machine and run it.  In this case, the VI block diagram is "running" on the Real-Time controller but you can still view the Front Panel on the development machine.  This is what we call "Front Panel Communication".  As I stated previously, this is really only meant for debugging purposes.  So, for example, when you build a Real-Time executable that runs on a Real-Time Controller, it will not have a front panel that you can view unless you use Web Services/Remote Front Panel.  I hope this helps!

Please let me know if you have any further questions.  Have a great day!