One Counter to Generate a Retriggerable Finite Digital Pulse Train with an NI 66xx

Updated Jan 11, 2018

Reported In

Hardware

  • PCI-6602
  • PCI-6601
  • PXI-6608
  • PXI-6602
  • PCI-6624
  • PXI-6624

Driver

  • NI-DAQmx

Issue Details

Is it possible to create a finite digital pulse train using only one counter on my NI 66xx using NI-DAQmx?

Solution

  1. Create a single counter task 
  2. Create a start trigger and a pause trigger for this task.
  3. Use an external source to create a pulse of a desired width in order to achieve a finite pulse train that uses a single counter on card.  
Use the example below for reference. The external signal is passed to Dev3/PFI0, which has been configured to be the pause trigger source terminal.
 

Additional Information

Normally when performing a finite counter output operation, two counters are required. One counter is used to actually output the pulses and the other is used to gate the first counter and therefore output a finite number of pulses. You can accomplish this same behavior with a single counter is by setting up a continuous pulse output task with a start trigger and a pause trigger. The pause trigger takes the place of the second counter normally used as the gate signal, freeing this counter to be used for other operations.  

Pause triggers are only valid for continuous sampling mode with implicit timing. You can find the properties for the property node in the following locations:
  • Properties»More»Pause»Trigger Type
  • Properties»More»Pause»Digital Level»Source
  • Properties»More»Pause»Digital Level»Pause When
For each property, right-click the terminal and select Create»Control or Create»Constant  from the shortcut menu.

WAS THIS ARTICLE HELPFUL?

Not Helpful