vi behavior differs with runtime engine

[Kevin R.]

I am calling a vi(Labview 7.1) from TestStand(3.0) and have configured the vi to show the front panel when loaded and when called. The option to "close afterwards if originally closed" is unchecked. This vi behaves just as I would suspect when using the Labview Development System. However, when I configure TestStand to use the Labview 7.1 Run Time Engine, the front panel is loaded and displayed briefly, but then disappears.

Can anyone explain this behavior I am observing?

[ryank]

When calling it from TestStand, the actual instance of LabVIEW (RTE) is probably being terminated, thus causing the VI to be unloaded. The best thing to do would be to write the VI so that it has a while loop and a stop button to close it.

Regards,
Ryan K.

[Kevin R.]

Thanks for the feedback Ryan. The behavior I am shooting for is for the vi to remain open during the entire sequence execution, acting as a console, displaying command line interface activity. I don't think the while loop suggestion won't work for this application...any other ideas?

-Kevin

[Dennis_Knutson]

If you want a VI to run continously in the background, what you could do is have TestStand call a VI that opens and runs a different VI using the methods Open FP and Run VI. Not sure what about the monitoring part though.

[ryank]

I think Denis's idea might work, alternately, you could use the while loop and use some method of communication between LabVIEW and TestStand, say a temporary file.

Regards,
Ryan K.

[ryank]

You could use TCP/IP or datasocket as well (i.e. have one LV app that is always running, and call another one which would communicate with the first using TCP/IP. which you would call when you wanted to add data to the monitoring VI).

[Kevin R.]

Yes, Dennis's idea did work...thanks to both of you for your help and suggestions.

-Kevin