How do I monitor VI run time?

[T_Bragg]

I have tried using the Elapsed Time express vi, in both the sub-vi as well as my main vi. What I get out is the elapsed time only updates on the "sub-vi" when it finishes each process, and the calling vi only updates the elapsed time when the sub-vi finishes. My sub-vi takes approximately 7 hours to run, so I would like continuous updates so the user knows about how long is left to run. Is there a better way to have an elapsed time displayed?

[BrianInTheForest · Accepted solution]

You could use a global variable or a functional global to pass elapsed time up from the subvi to the main vi.   In your subvi you need to periodically poll the elapsed timer so it can be passed up.  You could put the elapsed timer in a parrellel loop in your subvi.

[JFMoynihan]

As I understand it you have an elapsed timer in your subvi to show the execution of each process and an elapsed timer in your main vi to show the total time.  I was wondering if you have set the Auto Reset off (to False) on the elapsed timer in your main vi?  By default Auto Reset is set to true, which means every time you start a new loop in the main vi, the timer starts over again.  By setting the Auto Reset to False, the total time will accumulate.  You can  then create an indicator inside the main vi and attach it to the Elapsed Time output of the elapsed time.vi. 

I hope this is helpful. 

John

[Coq_Rouge]

You could also use a reference. Some people in this forum are very hostile both global and locale variables. Just use them with care;). They want ruin your application if you have a few containing a small amount of data, that are not updated to often

[T_Bragg]

I simply added a parallel loop that only contains the Elapsed time function. This will work just fine.

Thanks,

[Coq_Rouge]

I aslo hope you put in a "wait (ms)" in that loop, set to say 1000 😉

[T_Bragg]

I spoke too quickly. The parallel option look good, but then I realized, if I place it in my main VI it will not stop when the main function is done. If I place the elapsed time in the sub-vi, I still won't get updated in the main vi until the sub-vi is done. How do you periodically pass information from the running sub to the main, without the sub actually completing?