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Why No Period or Frequency Trigger?

Question asked by mr.crc on May 4, 2015
Latest reply on May 8, 2015 by thomas001
Hi:
Once again I'm trying to figure out if/why a frequency is intermittently out of range, and I can't configure a DSO-3000X scope (or any other, for that matter) to trigger when one edge is greater or less than some period after a preceding edge.

In the present case I have 128Hz diagnostic pulses coming from a uC ISR which bit bangs an IO pin high at it's start, and low when it's done.  Every once in a while, the period between these pulses is about 3 us short, ie. 7.810 instead of 7.813 us.

Well, I want to trigger on this.  But I can't!  I know about pulse width triggering, but that isn't going to work because the high pulse duration is variable.

Without debating the fact that I can recompile my code to only emit a fixed duration diagnostic pulse, and then may be able to get pulse width triggering to do what I want (actually no, because then I will loose the ability to see if the errant period is correlated with the pulse width variations), the point is:

There really should be period triggering.  There is one other thread on this from 2013.  I'm surprised there aren't more.  I have certainly wanted to do this at other times in the past, in one case having to do with PLL design/troubleshooting.

BTW PicoScope has this capability...

If I try to make a feature request, is it likely to be implemented?  

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