Timer callback in LabVIEW

[RobBoyer]

Hello,

Does anyone know if there are any standard event sources that can provide basic timer callback functionality in LabVIEW?  My hope is that there is some code that can be leveraged so that I can pass a custom callback VI into a reg event callback node.  (For those out there familiar with Visual Basic, I'm looking for similar functionality to the timer control that kicks off an event handler every x millioseconds.)  I'm sure this could be done with the built-in timing VIs, but I have concerns about the accuracy of them and the existing code I'm building on (the TestStand 3.0 full-featured run-time OI) handles virtually all events with callbacks, so the consistancy would be nice.  It seems like it would be useful to lots of LabVIEW programmers for such a timer event source (perhaps leveraging the Windows multimedia timer) to exist so I'm hoping usefulness leads to existence.  🙂

Thanks to anyone with suggestions or pointers!

Rob

[TreyB_NI]

I'm not familiar with what a timer callback is.  It seems to be something more commonly used with text based languages.

What are you trying to accomplish overall?  Register a VI to occur when a timer has reached a certain value?

You have posted on the TestStand forum with a LabVIEW question.  In the future, you would likely get a faster response if you posted on the LabVIEW forum.

Trey B
Applications Engineering
National Instruments

[RobBoyer]

My apologies for putting this in the TestStand forum - I thought I had posted it to the LabVIEW one.  In any case, you are right - my goal was to register a VI to run every x seconds.  But I've pretty much given in to implementing it as a loop with a "wait until next ms multiple" call... so this post can quickly be relegated to the cross-posted-inconsequential-question message board. 😕

I was just hoping to avoid using the built-in timing VIs, because I had heard there are some issues with accuracy and inconsistent behavior under some circumstances.  Anyway, thanks for responding.

Message Edited by RobBoyer on 08-30-2007 07:36 AM