Change Detection with NI-9403

[DucPhung]

Hi all,

I am using NI-9403 to monitor a DIO line, when a change is detected, generate an event to perform some specific task. When I run the program, I got error 201020 - Lines specified does not support change detection. Is NI-9403 not the correct module for this purpose? if that is the case, which one should I use?

Thank you,

David

[GerdW]

Hi Duc,

instead of letting DAQmx generate an event you could compare the previous state of that DIO line with the current state and generate your "event" on your own!?

No need to use a different module…

[DucPhung]

Does it mean that I need to have a loop to poll the line for change in status? I hope I could avoid that by just passively waiting on an event.

Thank you

[GerdW · Accepted solution]

Hi Duc,

Does it mean that I need to have a loop to poll the line for change in status?

Yes.

I hope I could avoid that by just passively waiting on an event.

What's the problem with a loop running at (maybe) 25Hz or 50Hz?