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3404A advanced trigger fault?

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3404A advanced trigger fault?

Postby mike thomas » Thu Mar 14, 2013 7:03 pm

I'm seeing some odd behaviour with my new 3404A related to pulse width triggering. I'm hoping its not a fault but I dont see what else it can be unless there is a bizarre bug in the picoscope software.

All channels are functional and simple edge triggering works ok on all channels, but pulse width triggering only works as expected on channels A and B.

I am using a sequence of pulses of width 0.75ms, 1.5ms and 2.2ms and triggering from A or B I can selectively trigger on any of these widths.

Triggering from the same signal applied to C, D or Ext gets the result that width conditions 'less than' or 'outside range' trigger on any pulse, and conditions 'greater than' and 'inside range' never trigger.

Any suggestions ?

Mike.
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Re: 3404A advanced trigger fault?

Postby ziko » Mon Mar 18, 2013 12:05 pm

Hi Mike,

I have recreated your problem, I assume you are saying that on less than and outside it works, but on greater than and inside it doesn't work.

I have reported this as a bug.

Best regards
Ziko

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Re: 3404A advanced trigger fault?

Postby mike thomas » Mon Mar 18, 2013 2:37 pm

Thanks Ziko.

I would not say that less than and outside are working since the width qualifier does not have the desired effect.

For example, with a pulse 1.5ms wide and triggering condition set to less than 1.1ms A and B do not trigger (as expected) but C,D or Ext do trigger.

Change the triggering condition to greater than 1.1ms, then A and B trigger (as expected) but C,D,or Ext do not.

Change the triggering condition to outside range 1.1ms to 1.8ms, then A and B do not trigger (as expected) but C,D,or Ext do trigger.

I have now reproduced some of this behaviour using the SDK so it would seem to be a driver problem.

There are also anomalies with the 'window pulse width' advanced trigger, which works or not depending on which channels are enabled. The dependency seems complicated but as one example a signal which correctly triggers when only A is enabled will stop triggering when any mix of the other channels are also enabled.

Mike.
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Re: 3404A advanced trigger fault?

Postby ziko » Mon Mar 18, 2013 3:50 pm

Hi Mike,

Yeah I have looked into it a bit further and it seems to be behaving strangely, on channel C, D or EXT it seems like its to trigger when its not supposed to and NOT trigger when its supposed to. In any case this has been reported as a bug.
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