minpulsewidth for digital input

[DCT]

Good day

I am using LabVIEW 8.2 with DAQmx 8.8 and USB-6251.

I have two optical sensors that output a logic 1 for the duration the beam is interrupted. I am having a problem with flickering of the output, most likely due to electromagnetic interference. since the pulsewidth of each flicker seems to be very short, what I would like to do is make use of the DAQmx property node to set the minpulsewidth for the digital inputs. I have attempted this and could not find the minpulsewidth option in the DAQmx Channel properties, so had to use the DAQmx Trigger property (Start.DigEdge.DigFiltr.MinPulseWidth). Despite looking like the correct property, this does not work either and system behaviour doesn't change regardless of the value of minpulsewidth.

Could someone please offer some advice on how to go about setting the minimum pulse width that the digital input will register as a pulse?

[Brandon_B]

Hello DCT,

The property you are looking for is in the DAQmx Channel Property Node.  If you select Digital Input »  Digital Filter » Minimum Pulse Width you can then wire a number for the number of seconds it takes to determine a valid state transition.  Also, be sure to place the property node before the DAQmx Start Task.  Try this out and let me know how it works.

Regards,