When a vi hangs...how do I find out what it is waiting for?

Question

I have a vi.  It is "waiting for front panel activity".  I cause some front panel activity by pressing a control...and the vi functions.  I then press the same button again and the vi hangs, the front panel does not respond to any mouse activity.  When I run the highlight execution function it shows that the case controled by the value change of the control executes to the end in the true case, but then there is no further action anywhere on (in) the vi.
How do you find out what the vi is waiting on to proceed, or which element "has the ball" so to speak.
Thanks
Stopped Humming for a while.

Answer 1

If you have event structures, you usually have no longer any need for "wait for front panel activity". This was more of a cheap bandaid solution before the introduction of the event structure.
Many front panel operation don't need to trigger any events or do anything, so spinning the "wait for activity loop" everytime something is clicked is a total waste of resources.
You should create events only for  things that really do something while other controls (e.g. configuration) don't need to be serviced by any event. The control will keep the data until it is needed by the code.
Here is an example:
You need to set aquisition parameters (rate, # of points, etc.) then press a button to start acquisition. None of the paramter settings need any events or need to spin any loops. Once start is pressed, their last settings will get read from the terminal anyway if the code is layed out correctly. And so on....
LabVIEW Champion . Do more with less code and in less time .