Compiled application on cRIO is very slow

[ChristianEC]

Hello,

I have an RT-application created with LV2009 that runs on a cRIO 9074.

If I run my application from inside LV2009, it runs in real time on the cRIO, as expected.

If I compile the identical application into a rtexe that should run after the cRIO was booted, the sample time (10 ms) is never achieved. It seems as I get overuns in every cycle.

All settings regarding the timing of my timed loop are identical in both cases. 

Why is there such a big difference? What can I do to run the compiled application in real time too?

Thank you in advance,

Christian

[ChristianEC]

I did some further tests and it seems that the call to an external library using the Call Library Node-VI is causing the bad performance.

I have created a library for VxWorks that is located on my cRIO and is called every cycle.

I am bit confused why the same type of call had no bad issues when running the real time application from LabVIEW directly.

[ChristianEC · Accepted solution]

I found the solution of this problem. It seems to be no good idea to specify that the Call Library node should run in UI thread. Obviously, there is no UI thread when running a compiled application on cRIO.

Christian