05-29-2009 01:30 PM
06-01-2009 03:09 PM
Hi hiltnerj,
Have you tried to apply a digital filter? To do this, You'll want to place a DAQmx Trigger Property Node, and then choose Start»Digital Edge»Digital Filter» Enable. This should help- let me know how it works out for you!
06-01-2009 05:32 PM
I have tried this, but when I try to add the digital filter property and the digital filter duration properties to the property node, I get an error that I can't find the defintion for when I try to run the VI. I am not sure if the 9172 chassis supports digital filters on trigger lines. I also tried adding a 'dummy' counter to allow the filter to be turned on and set up, and this runs without error but doesn't seem to have any impact on the triggering. I'm running my engine right now so I can't get the error code (can't switch over the the VI with the filter) but I'll send the error number when I try again.
Thanks,
hiltnerj
06-02-2009 12:26 PM
06-02-2009 04:12 PM
Hi Hiltnerj,
I appologize, I was wrong in my last post, and as you suspected, you cannot use a digital filter on cDAQ, as explained here in the cDAQ manual. You should be able to set up a counter input (like an edge count) on the same trigger line and when you set up filtering for the counter it should filter the trigger line as well. Another option is to set up a retriggerable single pulse output, then trigger off of the single pulse. Since a retriggerable pulse will ignore triggers received while it is generating, you'll only get that first edge. Hope that helps, let me know if you have any questions about that!
07-16-2012 03:44 AM
Hi All,
Just to clarify the solution to this forum thread, as of DAQmx 9.4 onwards support has been added for Digital Filtering on CompactDAQ, the readme file found here for 4.0 states under "New Features": Support for digital filtering on the NI cDAQ-9171, 9174, 9178, 9181, 9188, and 9191.
The solution to resolve this is to download 9.4 or above of DAQmx (ensuring the version supports your Operating System and NI Software Environment versions) from www.ni.com/drivers