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6k series: trigger on aux

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6k series: trigger on aux

Postby darko.veberic » Thu Jul 06, 2017 5:06 pm

Hi,

in our DAQ project, which runs on linux 16.04 LTS, we were up to now using a 6403B PicoScope (on USB2).
Since we wanted to read-out all four channels, we decided to bring the external trigger to the PicoScope via the AUX channel. The external trigger is a simple NIM signal, ie on DC50 it has 0V for logical false and -0.8V for logical true so that AUX input seems perfect for this job. The trigger pulse is ~300ns long and the typical traces that we take are 4000 samples long at 0.8ns sampling time. In my code I used the SimpleTrigger functions to set up all this and the daq was working flawlessly.

Nevertheless, after an upgrade to a PicoScope 6404D (for bandwidth reasons) I've encountered really strange behavior. In the DAQ setup the new PicoScope did not trigger at all, reaching my call limit in polling of the IsReady. When I tried it on my desktop with a function generator closely mimicking the NIM signal, at first the PicoScope refused to trigger. After I left it running with an open GUI over the night, in the morning of the next day suddenly I could get it running. Unfortunately, installing it back into the DAQ setup, it still does not trigger. Just for test, I replaced it again with the old 6403B PicoScope and the exactly same code works flawlessly.

What could be the reason for such behavior? Are the new PicoScopes requiring some more setup steps which I am currently failing to do (and the old PicoScope just works fine because of the defaults?).

Thanks in advance for any help with this excellent devices.

Best regards,
Darko.
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Re: 6k series: trigger on aux

Postby Hitesh » Fri Jul 07, 2017 9:37 am

Hi Darko,

Does the issue also occur with the PicoScope 6 for Linux software?

The AUXIN connector has an 50 Ohm impedance so please check that the input matches that.

We are aware of an issue related to triggering using the auxiliary input with the windows driver which was fixed some time ago so it could be related. We are due to release a new version of the software for Linux so an updated libps6000 driver package should also be available.

Which programming language are you using?

Regards,
Hitesh

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Re: 6k series: trigger on aux

Postby darko.veberic » Fri Jul 07, 2017 10:30 am

Hi,

> Does the issue also occur with the PicoScope 6 for Linux software?

Do you mean with the GUI scope? I would say yes, but fiddling with the trigger settings somehow (I cannot reproduce it) makes it work.

> The AUXIN connector has an 50 Ohm impedance so please check that the input matches that.

Yes, NIM standard is current-based with logical true -16 mA (which into 50ohm gives −0.8V). So this should work correctly when the trigger level is set to -0.4V. And in fact, with the 6403A/B, it does work flawlessly. But not with 6404D.

> We are aware of an issue related to triggering using the auxiliary input with the windows driver which was fixed
> some time ago so it could be related. We are due to release a new version of the software for Linux so an
> updated libps6000 driver package should also be available.

I am getting the libraries via your debian apt repository. The current version of the picoscope deb package is 6.11.13-4r3 with libps6000.so.2.0.0. The ps6000GetUnitInfo(PICO_DRIVER_VERSION) returns "PS6000 Linux Driver, 1.4.6.13".

> Which programming language are you using?

The whole DAQ is written in C++ and we are calling your C api.

Best,
Darko.
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Re: 6k series: trigger on aux

Postby darko.veberic » Sun Jul 09, 2017 10:54 am

Dear Hitesh,

Hitesh wrote:We are aware of an issue related to triggering using the auxiliary input with the windows driver which was fixed some time ago so it could be related. We are due to release a new version of the software for Linux so an updated libps6000 driver package should also be available.


For us this is a total showstopper. Do you have any timeframe for the release of the new version? We can test it immediately.

Best regards,
Darko.
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Re: 6k series: trigger on aux

Postby Hitesh » Mon Jul 10, 2017 9:19 am

Hi Darko,

Could you please e-mail support@picotech.com and I will look to assist you further.

Thanks,
Hitesh

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