Timing of RT-application on cRIO

[haagy]

Hello

I am starting a project on cRIO (9034) using the scan interface mode and deploying the RT application onto the cRIO. Now I have the problem that even the simplest code (attached) fails to run smoothly. The output should just be activated in a constant frequency. But from time to time it sometimes is enabled/disabled way too long before getting back to it's rhythm. I think it could be some kind of wrong timing of the processor, but as I don't have experience in this topic I have to ask.

Does anyone know the exact problem or has tricks and examples on how to solve this problem?

Thank you in advance!

[GerdW]

Hi haagy,

Now I have the problem that even the simplest code (attached) fails to run smoothly.

As long as there is a Rube-Goldberg in your code you shouldn't call it "simplest"… 😄

The output should just be activated in a constant frequency.

There is some network communication in your loop: this is non-deterministic and could hurt your RT determinism…

[haagy]

Hi Gerd

Thanks for your answer. Could you tell me the best solution how to communicate deterministically between touchpanel-computer and the cRIO? Or how would you solve that problem?

Thanks!

[GerdW · Accepted solution]

Hi haagy,

put the shared variable into a parallel running loop. This way it can be read at its own interval.

Use a local variable (or notifier) to send this En-/Disable signal to your "deterministic" loop. You might try to use a TimedWhileLoop for communication with the ScanEngine.

How did you configure the ScanEngine?

[haagy]

This worked, thank you very much!