Yesterday I was using my pico to check a inductive crank shaft sensor on a corsa at work, set the scope up and used the preset for cranking. Took a recording and stopped it using the space bar but it wouldn't let me view the captures I had taken. Tried using the little compass symbol and the blue arrows at the top. All it seemed to have recorded was the screen from when I stopped it. It then crashed and locked up not long after, I thought it was due to my laptop running around 4 programmes at once so restarted.
Today I used it again to check 2 rear abs speed sensors on a chevy aveo, recorded 30 odd screen captures . Stopped the recording but again wouldn't let me view what I had recorded. It was only showing the on s teen image in the buffer.
I contacted pico technical who advised to restart and unplug and reconnect the scope etc. had it running in demo mode and everything was working fine. Rechecked it on a corsa O2 sensor and it worked ok, could view the screen captures in the buffer. I then connected it to the front abs sensor and it wouldn't let me go through the captures, was only showing the on screen image!? Am I doing something wrong?
I've contacted James at technical topics who is going to contact me after the weekend as he wasn't in. Do you guys have any ideas?
Seems odd how it doesn't let me view anything with a AC wave?

I've had somewhat the same concern, I believe it to be software  , Using an earlier beta release I do not seam to have the problem ....  [smiley=huh2.gif]

Russ,

Were you in streaming mode with a low sample rate selected?  Got a data or settings file?  What version software?

What you describe sounds similar to this in 6.6.16.12:

Finally stumbled across this bug where you have say a 3/4 screen in streaming mode and maybe more screens captured before that one.

Stop the scope and the capture squishes up against the left side of the screen and any previous screens cannot be viewed.

This occurs only in streaming mode when samples are turned way down below what would be a useful setting.

Just found this by accident in class today demonstrating the results of a poor sample rate.

You should never encounter this if you are using a decent sample rate.  I only was able to duplicate this finally by showing what not to do... ;)

Tom Roberts wrote on Mar 2^nd, 2012 at 7:12pm:

This occurs only in streaming mode when samples are turned way down below what would be a useful setting.

That sounds similar to what I was having issues with too Tom.  I believe I was looking at oxygen sensor signals, which is why I turned the samples down so low, to filter out noise while viewing the pattern. 

Tom Roberts wrote on Mar 2^nd, 2012 at 7:12pm:

Russ, Were you in streaming mode with a low sample rate selected?  Got a data or settings file?  What version software? What you describe sounds similar to this in 6.6.16.12: Finally stumbled across this bug where you have say a 3/4 screen in streaming mode and maybe more screens captured before that one. Stop the scope and the capture squishes up against the left side of the screen and any previous screens cannot be viewed. This occurs only in streaming mode when samples are turned way down below what would be a useful setting. Just found this by accident in class today demonstrating the results of a poor sample rate. You should never encounter this if you are using a decent sample rate.  I only was able to duplicate this finally by showing what not to do... ;)

Tom,
That's the problem! Same software version.
When I tested the crank and abs sensors I was using the presets so didn't alter the sampling rate. However when I viewed the O2 using zirconia preset I could view the buffer although ( this may be me again) whilst in streaming mode the image is just a huge streaming block of blue. I have to stop it with the space bar to view the waveform....?

I did try and save the abs but it wouldn't let me then the software crashed. If I get a car in today and have some time will try and take a recording and save the file.

Cheers Russ

Ps if the issue is a sampling issue then what should I turn it up to on for example the abs preset. 50ks is what pico sets...  :)

Russ,

We recommend that you get away from using the automotive presets as soon as possible.  They are great for example study and the library is a good read but these are not optimized for best results to use for live work.

Take the ABS analogue selection, for example.  This is set for AC coupling.  That is incorrect.  You need to use DC.  And, yes.  That preset displays the bug quite nicely.   ::)

It should work OK boosting samples to 200kS or higher.

If this results in a hairy waveform, simply dial in some low pass filter after you have captured it to clean up as desired.

Running with filter can reduce sample rate.  In streaming mode you will not see the filter effect until the capture is finished anyway.  Just run without filter and filter your capture afterwards.

We don't usually provide specific PicoScope help outside of the Picogroup area but this is an issue where a software bug is involved that has a simple workaround and we want eveyone to be able to use this release. 

Thanks for sharing this with us.  We have had only a few mention this issue and only yesterday was I able to duplicate it and see what was happening.

Tom,
Thanks for the help, your explanation about streaming and using the filter will help me out. I did manage to retest a abs sensor this morning and cranked up the sample rate to get rid of the bug!