Triggering and Streaming

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richk449
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Joined: Tue Jun 22, 2021 3:43 pm

Triggering and Streaming

Post by richk449 »

I'm trying to make a picoscope 4828 function like a regular oscilloscope through the python interface. (As a starting point - not because that is the end goal.) I am inputting a signal into channel A with periodic 5 V, 0.27 ms wide pulses at a period of 10 ms, with the voltage set to 0 outside of the pulses.

Because I want to continuously capture these pulses over a long period of time, I am trying to use streaming mode, with triggering. (Note that I don't really care about the data between the pulses, just the short window when the voltage is non-zero.) However, in my script, the triggering only works once, and then never again, even though many of the sets of data captured should meet the triggering criteria.

Does anyone know why the triggered flag is not true on subsequent data sets?

(For the record, if I run Picoscope6, it captures my signal exactly like I would expect.)
Attachments
PS4000aStreamingExample_x3.py
(9.77 KiB) Downloaded 119 times

bennog
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Re: Triggering and Streaming

Post by bennog »

In infinite streaming mode you don't use triggers.

Then you do the real-time analyse in your software on the incoming data stream.

Benno

richk449
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Joined: Tue Jun 22, 2021 3:43 pm

Re: Triggering and Streaming

Post by richk449 »

bennog wrote:
Thu Jun 24, 2021 7:50 am
In infinite streaming mode you don't use triggers.

Then you do the real-time analyse in your software on the incoming data stream.

Benno
Thank you. The problem I am running into is that the highest sampling rate allowed in infinite streaming mode is much lower than what is allowed in block mode, or the sampling rate that Picoscope 6 achieves. I want to get the same performance as Picoscope 6 (sample rate during capture, and waveform update rate) but I can't come anywhere close with any of the modes. With streaming mode, I can achieve an acceptable waveform update rate, but low sampling rate in the capture. With block mode, I can achieve a good sampling rate in the capture, but a very low waveform update rate. With rapid block mode, I can achieve a good sampling rate and waveform update rate, but only for a fixed number of cycles. I need to run continuously (days, months, years) not just for a fixed number of cycles.

Gerry
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Re: Triggering and Streaming

Post by Gerry »

Hi richk449,

Sorry for the late response,

Could you post a psdata file for the capture that you say you can achieve in PicoScope 6?

Regards,

Gerry
Gerry
Technical Specialist

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