Trigger issue

ron · Post by **ron** » Mon Feb 20, 2006 11:58 pm

Just received my new 3206 and I'm having issues with triggering.

I have an old tectronix SC 502 15 Mhz scope with a SG 502 oscillator. I generate a 100 Hz sine wave, set my trigger level, and it shows up on the analog scope no problem locked, without any jitter - as expected.

I send the same sinewave into the 3206 and no matter what trigger setting I use - it's not locking solidly. If I set the trigger close to one of the peaks it seems to settle - but its still jumpy.

It seems to lock on square waves much better.

I'm running the latest SW currently posted on the site - 5.12.7.
Even tried the power adapter - no noticeable difference.

What am I missing here?

Ron.

Michael · Post by **Michael** » Wed Feb 22, 2006 9:55 am

Hello Ron

Try increasing the number of samples per scope trace. The problem you are getting is a low horizontal resolution. I have attached a screencast of changing the number of samples.

Bear in mind the 3206 has a 1 megasample buffer, one of the best features of this scope.

Best regards,
Michael

ron · Post by **ron** » Wed Feb 22, 2006 3:49 pm

Michael,

Thanks for the info. I tried replicating your example using the built in waveform generator - 200 kHz, using settings visible on your sample. It locks good. It seems with higher frequency signals, it locks fine.

The issue is with low frequency singals - in this case I'm trying a 100 Hz sine with the sample rate of 50000 and am not getting a lock. Its as if the software does not know what the slope is, and the waveform is "flipping" regularly.

Can you try a 3206, looking at a 100 Hz sine using the built-in generator, and let me know what you get? Maybe I have a bad 3206?

Thanks!

Ron.

Michael · Post by **Michael** » Wed Feb 22, 2006 4:13 pm

Hello Ron,

You may well have a faulty unit. I have tested a 3206 off the shelf with no problems.

Please post a psd file from PicoScope on the forum for us to have a look at.

Best regards,
Michael

ron · Post by **ron** » Tue Feb 28, 2006 2:00 pm

Here's a link to a sample psd file.

The waveform generator output is connected to channel a.

I get the waveform "flipping" - can't seem to lock on based on slope.

Ron.

http://www.mente.com/waveforms/2006_02_22_004.zip

Michael · Post by **Michael** » Thu Mar 02, 2006 10:20 am

Hello Ron,

This could be a faulty unit, in which case we can repair it for you under warranty(please refer to Pico terms of warranty).

Please confirm you are using the latest version of the software. Your last post states that you are using 5.12.7 compared to the current 5.13.7

Please confirm this and if the problem persists, please contact us on support@picotech.com

Best regards,
Michael