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Triggering Question

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Triggering Question

Postby BWJ » Sat Dec 12, 2015 6:12 pm

All,

I have two Pre-sales questions about triggering, both analog and MSO.

In most benchtop oscilloscopes, you can set up the triggering to automatically repeat trigger on a repetitive signal,
so that you can continually see minor differences in successive sweeps. You can also simultaneously adjust the horizontal and vertical settings which are then persistent until you further adjust them, and these setting do not change as a side effect of triggering.

My first question is, can the 3XXXD MSO family conform to this behavior, with respect to both analog and digital triggering, and also show the analog and digital signals on the same X-axis, so that you can visually (and with cursors) correlate events in both signal types?

Most of the lower level logic analyzers don't support this ability. They all seem to want to completely reinitialize the view on each data collection, and require a manual stimulus to repeat the collection, after which you have to tediously readjust the view.

Also, my second question is: can you trigger on some combination of the analog and digital inputs?

BWJ
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Re: Triggering Question

Postby AndrewA » Wed Dec 16, 2015 5:03 pm

Hi BJW,

Changing the trigger options does not affect the voltage ranges or timebase of the scope.
If the scope is capturing and you change any of the options the scope will restart the capture.
The digital channels are displayed in separate area below the analog channel area but time rulers cross both areas.
Voltage cursors are not available in the digital/logic channel area.
Time cursors do not adjust to match if the timebase is changed.

Yes you can trigger on combination of the analog and digital inputs. Please our logic trigger functions-
https://www.picotech.com/library/application-note/using-the-picoscope-logic-trigger-functions
Triggers on digital channels can be either a level or edge or a combination.
Regards Andrew
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Re: Triggering Question

Postby BWJ » Thu Dec 17, 2015 11:40 pm

Andrew,

Thank you for your response. However, it did not approach an answer to my first question. I was not talking about changing anything while capturing. My question is much more subtle than that. The issue is, if you do a capture, especially in the digital domain, then the first time you do it, you generally have to adjust the display parameters to optimize time scale zoom and slew factors to best see what you want to see.

The question, broken down into parts:

1. If the signal suite captured the first time repeats itself periodically, can the trigger mode be set so that the capture will also repeat periodically WITHOUT my needing to manually interact with the unit? This specifically means not needing to manually rearm it for another capture sequence.

2. Assuming the answer to the previous is YES, then if after the first capture I manipulated the display zoom and time offset with respect to the trigger point, then enabled the repeating trigger/capture, then after the second and later capture, will the selected zoom and time offset still be identical to what I set up, so that after every trigger and capture, the display will look identical to the way I adjusted it after the first capture?

Most oscilloscopes I have used can do this for their analog inputs. I am asking if the PicoScope 3000 series can also do this for the digital inputs. For me, any logic analyzer that cannot do this is tedious and therefore awful to use. If I repeat a capture that I was happy with, I should not need to do anything after any subsequent (and automatic) capture, and still continually see the same result.

I also expect this capability in the mixed signals case.

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Re: Triggering Question

Postby AndrewA » Mon Dec 21, 2015 3:50 pm

Hi BJW,

1. If the signal suite captured the first time repeats itself periodically, can the trigger mode be set so that the capture will also repeat periodically WITHOUT my needing to manually interact with the unit? This specifically means not needing to manually rearm it for another capture sequence.

Yes - Set the trigger to repeat

2. Assuming the answer to the previous is YES, then if after the first capture I manipulated the display zoom and time offset with respect to the trigger point, then enabled the repeating trigger/capture, then after the second and later capture, will the selected zoom and time offset still be identical to what I set up, so that after every trigger and capture, the display will look identical to the way I adjusted it after the first capture?

Yes - Changing the settings will not stop the scope capturing.

You can use the zoom feature when the scope is still capturing.
If you change the trigger time offset or delay this will restart the capture automatically
Note- Time cursors do not adjust to match if the timebase is changed. (They stay in same place on the screen)
Regards Andrew
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