Why do I get more than 1 triggered signal with the Trigger and Gate Express VI?

[bmaki]

I am trying to capture one cycle from a larger signal.  In the larger signal, I capture 16,000 (about 89 miliseconds) points to ensure I get at least one pulse.  Then I run the signal through the Trigger and Gate Express VI.  I want to create a waveform with about 30 samples before the trigger and about 30 samples after. 

My problem is that the triggered measurement output sometimes gives me 1, 2, or even 3 pulses.  I believe that I have set it up correctly.  To my understanding, the "Reset after each trigger found" should only output the data I am looking for.  I set up to have 30 pre-trigger samples, then 8,100 samples after the trigger. 

Why am I getting the extra pulses?  Especially when my input signal only contains 1 pulse?! 

Thanks!

[David22JRA]

Hello bmaki

Just to make sure what is the DMM device you are using? Which driver version are you using?

Regards

[bmaki]

Hi David22JRA,

I am using PXI-4070 with NI-DMM driver 3.1.0.  I was originally using a PXI-2503 Matrix Relay Card to switch to my measurement.  When I get this tester back in the middle of next week, I will try a direct measurement.

I did find out that if I take the initial measurement and save the data with one VI then input that data into the Trigger and Gate function in a another vi, it works; I always get one pulse according to the way I have set up the Trigger and Gate.

I am just unable to reliably get that single pulse when I take the initial measurement and input it into the Trigger and Gate function in the same vi... unsure why.  I am interested to find out why this is!