How Can I Access The Trig Line On My PXI Controller to Input/Output A Trigger?

Updated Jun 29, 2018

Reported In


  • PXI Controller
  • PXI Chassis


  • LabVIEW


  • NI-DAQmx

Issue Details

My application requires that I use a pulse to trigger my measurements. I am looking to use the trig line on my PXI controller to input/output a trigger to the PXI backplane and use that as my trigger source. How do I access the trig line in software?


It is recommended you do not use the PXI controller trig line to trigger your measurement. Instead use another trigger source, such as a software trigger or a hardware trigger from an I/O module with an available counter output. 

Additional Information

The PXI trig line's recommended use it to reset the watchdog on your PXI controller and is not meant to export signals to the backplane of the PXI chassis, and no API exists to interface with this line.

Instead, depending, on your timing requirements, you should use a software or a hardware trigger to start your measurement.

An example of a software trigger is a simple boolean value change that is detected in software or read from an incoming serial stream.

Hardware triggering can be achieved in a variety of ways depending on the triggering method. For more information see NI-DAQmx Data Acquisition Triggering Techniques Using LabVIEW.


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