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Resolution enhance interaction with Sin(X)/X interpolation

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Resolution enhance interaction with Sin(X)/X interpolation

Postby CoyoteDavid » Wed Aug 25, 2010 8:02 am

I seem to have a wierd problem where the resolution enhance feature does not always work when I have Sin(X)/X turned on. I have a 3424 set to 16 bit resolution. At first, I get no enhancement. If I then turn off the Sin(X)/X, the enhancement starts. Then sometimes, when I turn it back on, it stays enhanced, sometimes it goes away.

To show the problem, I setup with channel A as 12 bits, Auto. Channel C as 16 bits, Auto. Connect a square wave at 1 kHz, trigger on A in the center of the screen, 10 uS/div, >=100k samples. Now toggle Sin(x)/X on and off and observe the waveform. The enhancement for C comes and goes with the Sin(x)/X interpolation.

Is this normal?
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Re: Resolution enhance interaction with Sin(X)/X interpolati

Postby ziko » Fri Aug 27, 2010 9:44 am

Hi that is strange because I do not seem to have this problem. What software version are you running? Could you send an example waveform?
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Re: Resolution enhance interaction with Sin(X)/X interpolati

Postby CoyoteDavid » Sat Aug 28, 2010 6:06 am

Hi Ziko,
My version is 6.4.64.0

I have attached the psdata file of when it occurred. I also experimented a bit more, and found that as soon as I saved the psdata file, it fixed itself! I tried it several times. The sequence to recreate is as follows:

1) Bring PicoScope up from icon on desktop (not a psdata file, this is important)
2) Connect 1 kHz square wave to channel A and C, A in 12 bit, C in 16 bit, both auto scale, 20 uS/div (or 10, or 50, etc.).
3) Notice that channel C looks identical to channel A, no enhancement.
4) Now go FILE->Save Current Waveform As... and save a data file. I used the file name "EnhanceNotWorking.psdata".
5) Since that stopped the acquisition, hit GO again. Notice that enhancement is now working like it should.

If you look at the thumbnail for the file I attached, it shows the waveform of the non-working enhancement. If you double click the file, to bring it up, the enhancement instantly starts working, and the waveform shows it working (not like the thumbnail).

Does this help?
Attachments
EnhanceNotWorking.psdata
(15.31 KiB) Downloaded 109 times
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Re: Resolution enhance interaction with Sin(X)/X interpolati

Postby ziko » Thu Sep 02, 2010 8:46 am

Hi I cannot recreate this problem.

I have taken a video of what I was doing, can you verify if I am doing exactly the same?

http://screencast.com/t/NTJlMGQzOWUt

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Re: Resolution enhance interaction with Sin(X)/X interpolati

Postby CoyoteDavid » Sun Sep 05, 2010 7:34 am

That does appear to be the same. I put a video up also, to show the problem when I do it:

http://screencast.com/t/OTllMDdkMzA

This shows another display problem that seems to have appeared also. The second half of this shows the problem I talked about.

BTW, I just loaded Jing, which I discovered from your post. Thank you!
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Re: Resolution enhance interaction with Sin(X)/X interpolati

Postby ziko » Mon Sep 06, 2010 11:18 am

Yeah its pretty good, if a pictures worth a thousand words and a video is worth 25 pictures in a second then one seconds video is worth 25,000 words!

Anyway on a serious note I have managed to recreate your problem, there is a bug in the software however not for the same reasons that you may think.

Sin(x)/x will override any of the filtering options depending on a threshold defined under interpolation. So if you defined 1000 samples then if you drop below 1000 then Sin(x)/x will remain on and your res enhancement will not switch on. However the software is not doing this and is getting stuck so this will be fixed. Now in terms of the other problem can you try doing the same set-up without probes set to x10?

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