Capture X10 home automation protocol

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Computski
Newbie
Posts: 1
Joined: Tue Nov 01, 2022 6:14 am

Capture X10 home automation protocol

Post by Computski »

Hi, just aquired a 2000 series unit.
I am trying to capture the transmit waveform from an X10 controller.
I have channel A linked to the 50Hz zero crossing timebase, nice squarewave there.
The X10 output is a series of 1mS pulses coinciding with the ZC transitions.

Here's the issue. I want to capture the entire transmission sequence, which is basically a mark/ space code, and typically takes 50 ZC events (about 0.4s) to transmit.

I set the scope to trigger off B channel transition as I want to capture from start of signal (which is 3 marks). The scope captures over multiple frames, but its not clear that these are continuous from one another in time, or whether when one frame is finished, it waits to re-trigger, and if it is doing this then it will lose any sequential spaces because they won't cause a transition.

i.e. what I want is to trigger the scope and have it record everything (or lack of) for the next 0.5 secs.

What's a recommended setting for this? And is there a way to confirm the capture time is continuous rather than separate windows which might themselves be separated in time.

yeah yeah I could read the manual but forums are where the experts reside :-)

Gerry
PICO STAFF
PICO STAFF
Posts: 1065
Joined: Mon Aug 11, 2014 11:14 am

Re: Capture X10 home automation protocol

Post by Gerry »

Hi Computski,

Sorry for the delay in answering (circumstances have prevented me from answering forum posts for longer than we would prefer).

In case you haven't already resolved your problem, I'll give you an answer here. If you're using a TimeBase value of less than 50ms/div, then you will have gaps between your captures (where the data needs to be transferred to the computer). So, set the Timebase to 50ms/div, and change the number of (requested) samples (i.e. the value in the box to the right of the TimeBase drop down list) to maximum enter 2GS and it will reset to its maximum). This will allow you to capture the complete sequence at once, and use a fast enough Sample Rate to give you a reasonably clean looking waveform.

As I don't know what 2000 series PicoScope you have, I need to also tell you that, the sample rate that you need (for nice square waves) is at least 10 times the fundamental frequency of the square waveform i.e. 10kHz, which, even in a PicoScope 2204A would give you a complete capture on one Channel for 500ms (if you have a PicoScope with a larger Sample buffer then you will clearly be able to sample faster to get an even cleaner looking waveform).

If you haven't already done it, you can view the properties of your capture by going to the 'View' menu and selecting 'View Properties'.

Regards,

Gerry
Gerry
Technical Specialist

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