1. Home
  2. General Home Automation
  3. Recording X-10 PLC sequences

Recording X-10 PLC sequences

This was buried in another thread so I thought it might attract more attention in a thread all its own.

I've put together a very preliminary web page showing how I modified my ESM1 X10 Signal Meter to output signals for ZC and PLC activity which can then be viewed on an oscilloscope and/or recorded as a .WAV file using the LINE-IN input of a soundcard. The .WAV file can be viewed (and scrolled) in a wave editor. I use LoopRecorder for recording and GoldWave for viewing and editing.

The advantages are that the ESM1 is a low voltage device and is isolated from the powerline by its 12VAC wall transformer and that the ESM1's electronics do all the heavy lifting. All we have to do is tap into its data stream. The disadvantages are that we cannot see anything the ESM1 cannot see although we can see low level signals and noise which do not illuminate any LEDs on the ESM1.

I cut about 8" off the female end of a 3.5mm M/F adapter cable like...

formatting link
I stripped about 3" of the outer insulation and soldered the leads to the points indicated in the schematic on the web page. I can now just plug it into my soundcard using a 3.5mm M/M cable. I will add some photos to the web page in a few days once I get my network running again. (I lost a 7 port switch to a power glitch a few days ago.)

The preliminary page is at...

formatting link
CAUTIONS:

  1. Do not connect to any soundcard input other than LINE-IN.

  1. My ESM1 was made by Telesystems before ELK bought the rights to the design. I do not know whether the schematic (drawn by John Galvin) represents the current ESM1 design.

  2. I don't know if there are any limits on the size of a .WAV file for either LoopRecorder or GoldWave. All of my experiments have used 1 minute loops recorded at 8000 samples/second. Longer recordings will be cumbersome to view and edit even if the editor can handle the file size.
Reply to
Dave Houston
Loading thread data ...

I finally got my network fixed and have now added a photo showing the connections to make on the bottom of the ESM1 circuit board to add a 3.5mm stereo connector for recording via soundcard Line-In.

formatting link
I've also prototyped a stand-alone module that does the same thing. It works with 90-250VAC and doesn't need an ESM1. There's a brief description here...

formatting link
Since it involves mains voltage, I think the latter needs to be sold assembled and tested rather than as a DIY kit. If there's adequate interest, I'll work out the cost, design a circuit board and see if I can find someone to assemble and distribute them. I think it can sell for $25-30 including all cables (in N. America).

P.S. There's no real need for the ZC signal since the wave editors have time scales. Connecting both tip & ring to pin 18 of the ESM1 PIC eliminates the

60Hz hum.
Reply to
Dave Houston

Nice work!

I'm certainly interested in several. Will it run from a wall wart or have a built-in PS like the Monterey?

I'd try this mod, but I like my ESM1 - my soldering's not got enough to handle the job, I'm afraid. But I'll happily commit to whatever $75 will eventually buy!

I'm assuming that there will be lots of interesting stuff that can be done to analyze the signals once they've been captured to disk.

-- Bobby G.

Reply to
Robert Green

It's all passive components so there's no PS. It uses the power inlet on the right in this (non-PDF) link...

formatting link

You assume too much. Even the best soundcards can only sample at 96ksps which is too low for an accurate picture of the 120kHz waveform. The demodulated output will look like the ESM1 screenshots but, as it has no active components, will show all phases. The soundcard input must be limited to about 2Vpp or its built-in limiters will clip the signal so you'll have to adjust the maximum soundcard input signal level down to this level. You can later amplify it in the wave editor so you'll be able to make relative judgements of signal levels but cannot measure the absolute level. The major benefit will just be that you can record lengthy sequences to see what's actually on the powerline. X-10 interfaces only report valid codes - this gives a picture of collisions, middle-of-the-night mystery signals, etc. It's not likely to be a big seller - it probably won't even pay back the development costs.

I'll provide some screenshots in a few days.

Reply to
Dave Houston

I've added a picture of the prototype and a screenshot of an X-10 powerline signal recorded as a .WAV file with a soundcard.

formatting link
This should answer whether J STATUS REQUEST is really on the powerline or not.

Reply to
Dave Houston

Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.