2105 trigger/display problem

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2105 trigger/display problem

Post by CoyoteDavid » Sun Feb 11, 2007 8:05 am

My 2105 has what I think is a problem, and I was wondering if it is normal for the 2105.

I have the following settings:
20 microseconds/div, x1, +-10 volts range, vertical zoom off.
Trigger: Repeat, Rising, 1000 mV, -50%.
All other settings at default, (max samples set to 10000)
Input signal is a 5 volt square wave at 10 KHz. (Any signal will do)
The display of the waveform flashes on and off, and is there way less than 50% of the time, most of the time it is blank. If you hit stop, most of the time you get no waveform displayed, just the grid. This happens at 10 or 20 microseconds per division. Any other sweep rate seems to work fine.

I tried changing settings, and the vertical zoom, volts/div, AC/DC, horizontal zoom do not change the effect. Seem tied to the 20 microseconds/division (and 10 microseconds/division).

With further experiments, I found that the max number of samples seems to affect it as follows: 9996 is OK, 9997 to 10001 are bad, 10002 is OK. Also, at 9997 samples I tried several other sweep rates, and only the 10 and 20 microsecond/division have this problem.
I checked other values for max samples, and found that 4997 to 5001 are bad, while 4996 and 5002 are OK. Also, 2497 to 2501 are bad, 1247 to 1251 are bad, 622 to 626 are bad, 19997 to 20000 are bad, 20001 is somewhat OK, 20002 is OK.

I downloaded the PicoScope software again (5.15.6), reinstalled, and the problem is the same. I tried it on two different computers, with the same results.

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Post by ziko » Tue Feb 27, 2007 4:37 pm

Hi and thank you for your post.

I have recreated your test and I get exactly the same problem. This seems to be a bug, I have forwarded it to the relevant people. Thank you for your input.

Kind regards

Technical Specialist

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