Picoscope 6 + PS5242B

Forum for discussing PicoScope version 6 (non-automotive version)
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dkrypt
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Joined: Wed Aug 08, 2018 1:45 am

Picoscope 6 + PS5242B

Post by dkrypt »

Hello,

I am using Picoscope 6 with PS 5242B and the serial decoding works fine, the triggering on the serial bus also works fine, the signal generator works fine too.

However, when I wanted to use the serial decoding function together with the signal generator, it does not work. I was using Channel A (Scope) as the trigger source, to trigger on a Falling edge. I could not send out any serial messages, let alone see any signals from the GEN output. I realized later that the serial bus is grounded, when I clipped the GEN output to the data line of my serial bus. My serial bus is active high by default. When there is data, it will go low on the start bit.

What I was trying to achieve, was to wait on trigger for a falling edge (start bit) on my serial bus, and then, use the signal generator function in Picoscope to send out an arbitrary waveform.

Is there a way to invert the logic of the sig gen waveform? Otherwise, I can only use it as a standalone scope or standalone sig gen, but not together, as it grounds my serial bus.

Pls advise. Thanks.

Martyn
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Re: Picoscope 6 + PS5242B

Post by Martyn »

Can you send a picture of your circuit showing where you have the sig gen and the digital pins connected, including any ground connections. Can you also send in a psdata file that has the signal generator waveform you are intending to use.

If you send these to support@picotech.com we can take a look.
Martyn
Technical Support Manager

dkrypt
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Joined: Wed Aug 08, 2018 1:45 am

Re: Picoscope 6 + PS5242B

Post by dkrypt »

serial bus is still high
- open Picoscope 6 --> there's a clicking sound from picoscope hardware, serial bus goes low
- bus is grounded --> no communication is possible
-->
Here are the scope shots showing the difference between a standalone sig gen:
standalone_siggen_output.png
- serial bus is high by default
- clipping (crocodile clip) standalone sig gen's output (BNC) to the serial line will not ground the bus
- switch on output on standalone sig gen, pattern is sent out
- switch off output on standalone sig gen, pattern stops sending

and Picoscope's sig gen:
picoscope_gen_output.png
- serial bus is high by default
- serial line goes low on start bit
- clip (crocodile clip) output from Picoscope's GEN (BNC) --> serial bus is still high
- open Picoscope 6 --> there's a clicking sound from picoscope hardware, serial bus goes low
- bus is grounded --> no communication is possible