How to generate an Event on Digitalnput-ValueChange?!

[Anonymous]

Guten Tag and best wishes from Berlin!

I use an EventStructure (ES) with no Timeout. One Event that is handled
by that ES is the "Control1-ValueChange"-Event generated when the user
clicks the Control1. That's easy.

Now I have a DAQ-Card with Digital Inputs and I also want the
EventStructure to react on the Change of the value of one digital input
line.

I know I could set the timeout of the EventStructure to some ms and
check the DI after Timeout and then start the ES again and so on...

But well, I dont like this.
Is there another possibility?

Thanx a lot for your replays,
Stefan

[Wendy L]

Hello Stefan,

The event stucture is intended to capture user events, and not programmatic events.  This KnowledgeBase discusses this issue and a workaround.  Another variation of the workaround is to replacing the event structure with a case structure and wiring the digital line as the case selector, but it's similar to the solution you have already tried.

Hope that helps.

[Dynamik]

Hi Anonymous,

      You might want to check-out the DIO Change occurrence VIs (DIO\Advanced.)  I've never used them, but it sounds promising.  Hey!, occurrences are Events too! 

There's the "DAQ Occurrence", a "DIO Change Occurrence", VISA Offers it's brand of "Events", we can register the Event-case for a range of [user] events.  It would be nice to see NI "normalize" event-posting across different "systems" so that a single event handler could monitor everything.

Cheers.

Message Edited by Dynamik on 03-01-2006 05:31 PM

Message Edited by Dynamik on 03-01-2006 05:32 PM

[Anonymous]

Hello Wendy,

the link you sent me was very helpful. I will use the Property Value
(Signaling) to let the Event Structure get to know that the value of
the dig.line has changed.

Thank you.

Stefan