schift trigger

[__behemot_]

Hello,

I would like to measure, like in figure below. 

So first measure PWM signal and little bit before failing edge of PWM sample unkown digital signal.

Eventually I can sample for example 10% of PWM frequency after rising PWM edge.

Is it possible with PCI - 6251 and how to do this? 

I was trying to start digital signal acquisition with digital trigger (PWM) but I get error-200452 😕

[DavidVr]

Hey Behemot,

  In Your case as You have 6251 I would use an analog input channel to sample the digital line, cause in this case You can select digital edge as a trigger source(can be falling)and have pretrigger samples. You will have way more data than You need, You will hav to check only the first sample. This is the easy and fast way. You may find some useful information on the following link about triggering:

http://zone.ni.com/devzone/cda/tut/p/id/4329

Hope it helpes!

Best regards,

David Varga

Applications Engineer

NIH