Pico 5243D - Sync scope acquisition with AWG signal output

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Pico 5243D - Sync scope acquisition with AWG signal output

Post by MarBrunero » Tue Jan 29, 2019 4:55 pm

I would like to start a single acquisition of a finite number of samples at the same time of the generation of a single short pulse, using the arbitrary AWG, and repeat these two steps (pulse and acquisition) at the end of the previous acquisition, with the shortest delay possibile.

Ideally I would rather not split the AWG signal (the maximum output amplitude is already at the limit, being "only" 2 Vpp, for our application) and trigger both the pulse and the scope with LabVIEW. Will be possible to obtain a precise and stable synchronization using only a software solution?

Thank you,

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Joined: Tue Oct 21, 2014 3:07 pm

Re: Pico 5243D - Sync scope acquisition with AWG signal output

Post by AndrewA » Mon Feb 11, 2019 5:05 pm

This is possible by configuring the AWG to be trigger by software and can be run continuous in a loop. But the main issue is rearm time of the scope can be anywhere from 10-60ms, with a same capture settings, as I found out in testing this.
This caused by the scope having to transfer the data over the USB bus which timing varies.
If you wish to have the captures at a repetitive rate with a short rearm time I suggest you use raid block capture. But you will still have to stop the scope once the buffer memory is full and download the data.
In block mode the rearm time of the trigger around 1-2ms but in rapid block mode this is reduced to 1-2us.
Also the other thing you you could use is the Overlapped functions that will save calls to the driver, and reduce over all capture time. These can used for all block mode captures (block, rapidblock, rapidblockbulk).
See pages 56 and 57 of the PG- https://www.picotech.com/download/manua ... -guide.pdf
The overlapped functions is what picoscope 6 application uses. We currently don't have any LabVIEW examples that use overlapped functions.

To answer your other question- Basically starting the block capture and starting the AWG output at the same time with no trigger on the scope.
You can do this if you set the AWG Trigger source, to Scope trigger. And disable the scopes trigger, just call runblock to start.
The AWG output is always close to the end of the pre-trigger samples point. (With my setup it was about 27us delayed) But you would need to take a few captures with AWG connected to channel to use as reference, if you not going to have connected.
With this setup you can call the scope trigger functions before or after the signal generator function calls.
And won't have modified our LabVIEW llb files.
Let me know if you have any more questions.
Regards Andrew
Technical Specialist

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