Showing results for 
Search instead for 
Did you mean: 

DAQmx - Measuring only the pulses w/o pauses of a pulse train

Hi everyone,


I've got a problem which I hope you can help me with.

I'm using a NI 4461 PXI DAQ-card on a PXI realtime system and LabView 8.5.

I'd like to measure a pulse train @ 1900 Hz with very low duty cycle. In order to reduce the aquired data, I want to measure not the whole train but only the pulses leaving out the pauses in between. I set up the task to aquire a certain amount of pulses (100) at the maximum sampling rate (204,8 kHz) with a definite numbers of samples per pulse (50) and using an available trigger line to trigger the measurement of the individual pulses. I thought to set the Read out butter size to (number of pulses) * (samples/pulse) = 5000 to be able to first measure the high frequency pulses and read them out after the number of pulses is reached.

But unfortunately it's not working at all.

Could you tell me, how to configure a task to do that job, please?


Thanx in advance,


0 Kudos
Message 1 of 2

Hi Ralf,


Thanks for posting your question here. Are you still working on that issue? When you have done this, do you use the DAQmx-VIs or do you use a DAQmx-Assistant to configure the acquisition? There is also a website helping you to begin this or this tutorial.


Feel free to post any other questions here regarding this topic.



0 Kudos
Message 2 of 2