Using external 100ms pulse to start and stop counting of edges.

[KCO]

I am trying to count external VtoF pulses during a external shutter pulse.  I need to start the counter on the rising edge of the external shutter pulse and stop the counter on the falling edge of the external shutter pulse.  It would be best if on the rising edge of the external shutter pulse the counter was cleared to 0.  How can I do this using NI-DAQmx?

[S_Hong]

Hi KCO,

It seems like what you need is a pulse width measurement task. DAQmx has lots of great shipping examples in LabVIEW that you could refer to and help you get started with developing your application. You can view these in your Example Finder by accessing it under Help  Find Examples.... The example we are particularly interested in would be under Hardware Input and Output » DAQmx  Counter Measurement » Period or Pulse Width » Meas Pulse Width-Buffered-Cont.vi. This VI will measure the pulse widths of your input pulse and store the results in a buffer. There is no need to explicitly clear the counter to 0 for the next pulse since this is automatically taken care of by the DAQmx drivers.

Furthermore, I would like to mention that you can also narrow down your search by hardware. To do this, simply add a device in the  Hardware drop down menu in the bottom left corner of you NI Example Finder. You can then select your hardware and check "Limit results to hardware."

I hope this helps,