Search found 11 matches

by ben@willcockses.com
Sun Jun 17, 2018 8:16 am
Forum: PicoScope 6 for Windows
Topic: Calculating time difference between two signals
Replies: 8
Views: 3318

Re: Calculating time difference between two signals

I was also looking for the ability to measure the time from an edge on channel A to an edge on channel B, and was disappointed to find that such a basic feature was missing. More specifically, it's the ability to gather stats on the time that would be useful, for example to evaluate the jitter of a ...
by ben@willcockses.com
Mon Jan 15, 2018 10:46 pm
Forum: PicoScope 6 for Windows
Topic: High pulse width measurement inaccuracy
Replies: 18
Views: 4082

Re: High pulse width measurement inaccuracy

Martyn,
Any progress? Is it going to be fixed?
Rgds, Ben
by ben@willcockses.com
Mon Nov 27, 2017 3:09 pm
Forum: PicoScope 6 for Windows
Topic: High pulse width measurement inaccuracy
Replies: 18
Views: 4082

Re: High pulse width measurement inaccuracy

Yes, you're right, it's not really a problem with pulse width measurement - it looks more like a missing samples / incorrect timebase kind of thing. In retrospect my choice of subject description wasn't very good. Unfortunately it's the best PC I have available, so trying a faster one isn't an optio...
by ben@willcockses.com
Sun Nov 26, 2017 6:03 pm
Forum: PicoScope 6 for Windows
Topic: High pulse width measurement inaccuracy
Replies: 18
Views: 4082

Re: High pulse width measurement inaccuracy

Oops, that last link probably wasn't public... try this one:

https://drive.google.com/drive/folders/ ... sp=sharing
by ben@willcockses.com
Sun Nov 26, 2017 5:59 pm
Forum: PicoScope 6 for Windows
Topic: High pulse width measurement inaccuracy
Replies: 18
Views: 4082

Re: High pulse width measurement inaccuracy

I wasn't able to attach the files as they were rejected as too large (sigh). So I have put them on Google drive:

https://drive.google.com/open?id=1Jleod ... taFL-hPHPx

Rgds,

Ben
by ben@willcockses.com
Sun Nov 26, 2017 5:50 pm
Forum: PicoScope 6 for Windows
Topic: High pulse width measurement inaccuracy
Replies: 18
Views: 4082

Re: High pulse width measurement inaccuracy

Martyn, I re-ran it at 100ms/div (m_100ms_div.psdata) and 200ms/div (m_200ms_div.psdata). As before, the results were correct for 100ms/div but wrong for 200ms/div. I turned off the digital channels and tried again at 200ms/div (m_200ms_div_digital_off.psdata). This does seem to fix the problem. I'v...
by ben@willcockses.com
Tue Nov 21, 2017 12:46 pm
Forum: PicoScope 6 for Windows
Topic: High pulse width measurement inaccuracy
Replies: 18
Views: 4082

Re: High pulse width measurement inaccuracy

Martyn, PicoScope® 6 - PC Oscilloscope software version: 6.12.9.2917 Copyright © 1995-2017, Pico Technology Ltd. Model: PicoScope 2205 MSO Serial Number: CZ114/032 USB Version: 2.0 Calibration Date: 30 May 2014 Hardware Version: 1 Driver Version: 1.3.0.14 Firmware Version: 1.3.3.0 / 0.2.48.0 Thanks,...
by ben@willcockses.com
Mon Nov 20, 2017 9:01 pm
Forum: PicoScope 6 for Windows
Topic: High pulse width measurement inaccuracy
Replies: 18
Views: 4082

Re: High pulse width measurement inaccuracy

Bennog,

Thank you for suggesting that topic, but no, it quite obviously does not explain the differences I am seeing.

Ben
by ben@willcockses.com
Mon Nov 20, 2017 8:57 pm
Forum: PicoScope 6 for Windows
Topic: High pulse width measurement inaccuracy
Replies: 18
Views: 4082

Re: High pulse width measurement inaccuracy

Martyn,

Yes, if I change the slow sampling transition to 500ms/div, then the measurements are good at 200ms/div. So it appears there is a bug which only affects slow sampling mode - do you agree?

Thanks,

Ben
by ben@willcockses.com
Mon Nov 20, 2017 3:37 pm
Forum: PicoScope 6 for Windows
Topic: High pulse width measurement inaccuracy
Replies: 18
Views: 4082

Re: High pulse width measurement inaccuracy

Bennog, Thanks for pointing this out, but I was already aware of it. The thing is, I'm seeing good accuracy at the lower sampling rate, and lousy accuracy at the higher sampling rate. At 12.27KS/sec you'd expect to measure a 500ms interval to about 0.02% accuracy. At 2.5MS/sec, you'd obviously expec...
by ben@willcockses.com
Thu Nov 16, 2017 9:21 pm
Forum: PicoScope 6 for Windows
Topic: High pulse width measurement inaccuracy
Replies: 18
Views: 4082

High pulse width measurement inaccuracy

I have a circuit which generates an accurate pulse 500ms wide. I use the PicoScope 6 measurement function to measure the high pulse width between rulers. When the timebase is set to 100ms/div, I get sensible results: Min=500.1ms; Max=500.1ms; Average=500.1ms; sigma=24.46ns If I change the timebase t...