threshold edge counter daq card 6014

[lawrence23]

Hello there,

I used to count the number of very short pulses (50ns) with 5 V amlitude using a DAQ card 6014. Everything was ok.

As i have changed my setup, my new signal is now reduced to 1.7V and the DAQ card isnt able to detect any pulses... I cant find a way to change the detection threshold with that card, if it is possible. Could you help me, i am a beginner with Labview ?

Other question: is the threshold different if i count rising edges or falling edges?

Many thanks !

[Wayne.C]

Specs for 6014  https://www.ni.com/docs/en-US/bundle/370844b/resource/370844b.pdf indicate that an input high voltage must be between 2V and 5V.  This is a hardware requirement.  If the level does not go above 2V, then a rising or falling edge will not be detected.  You need to explore ways to increase the amplitude of the signal external to the DAQ device.  A zero to 5V signal would be the best.