Powerline modem

On a sunny day (Fri, 02 Nov 2012 15:40:52 +0100) it happened Marco Trapanese wrote in :

I'd probably grab an old 4046 or 2 :-) FM, PLL at rx end. I have used tthat over some cables. Wind some coupling inductors... Maybe a transistor or 2...

"Marco Trapanese":

If this is intended to be slow speed link for control/status purpose, I do FSK in the software of main microcontroller.

Vladimir Vassilevsky DSP and Mixed Signal Consultant

Well, I would shamelessly recommend my powerline modem library and reference design, that does BPSK in software on a dsPIC:

Drop me an e-mail if you wish to get more info.

Cheers, Andrzej Ekiert

Il 02/11/2012 17:04, Andrzej Ekiert ha scritto:

Interesting! I did something similar years ago - like an rtty transceiver. Ok, different frequencies but similar concept.

I was afraid it doesn't work on a noisy and wide power network of a large apartment.

But if you did that I'm sure it works! Marco

Well, it has its limits. Apartaments and residential households are generally easy. We have more trouble with large offices and industrial buildings, brushed motor machinery, etc.

Thanks for that confidence ;-)

Regards, Andrzej Ekiert

This appears to be 230/400 Vac 50 Hz environment with possibly three phases even in every apartment in an apartment building,

There might be problems communicating between devices, connected to different phases. The only communication path would be through capacitive coupling in the feeder cable to the distribution panel.

Il 02/11/2012 20:55, snipped-for-privacy@downunder.com ha scritto:

Here is very unlikely to have different phases in each apartment of the same building. Of course isn't possible to communicate between two apartments due to the power meter which "isolate" each one. But I don't want this. I want to communicate within the same apartment only.

About the coupling with the power line, do you know any app note that describes the best ways to design the front-end?

Thanks! Marco

I have 3x16 A circuit breakers for the electric stove in my 7th floor apartment (after a renovation two years ago). I have not measured, if the mains sockets in different rooms are on different phases.

I have only been involved with powerline communication, in order to prevent the buildup of internet service providers from using PLC technology, due to the RF pollution caused by these PLC systems.

Anyway powerline communication is usable at reasonable bit rates and reasonable distances. Have you studied for instance what couplers LON

Maybe rare in apartment buildings, but common in standalone residential houses. Anyway, easy do deal with using a capacitive coupler that could be installed in the breaker panel. Any three-phase device usually provides enough coupling to get the transmission going (e.g. a flow water heater, electric oven).

That's a common myth. Energy meters don't significantly filter signals in the CENELEC bands. Unless, of course, someone somewhere installs meters with a built-in filter. Having heard about that, I have yet to see such a thing in the field.

Regards, Andrzej Ekiert

Il 03/11/2012 13:55, Andrzej Ekiert ha scritto:

I'm talking about my (little) experience here in Italy.

I did some tests with my front-door friends and our energy meters prevent the communication.

Marco

Italy. You live in the only (I think) country that has deployed PLC for automatic meter reading on massive scale. May be that ENEL's modems/meters include filters to keep the medium quiet. You do have a solid state meter with a PLC modem, don't you?

Regards, Andrzej

Il 03/11/2012 15:17, Andrzej Ekiert ha scritto:

I guess you're right.

yep, this one:

Marco

It depends what you want.

how much range, how much bandwidth, how much cost....

Il 03/11/2012 15:31, Jasen Betts ha scritto:

within a single apartment.

about 2400 bps is enough.

as low as possible, of course ;) But I'd prefer smaller size rather than lower cost.

Marco

On a sunny day (Sat, 03 Nov 2012 15:39:04 +0100) it happened Marco Trapanese wrote in :

Use some of those 430 MHz modules. For example the fan control in my bathroom sends data that way to a big exhaust fan in the attic. Digital encoded commands, like a remote control.

exhaust fan in the attic.

My power company uses 2.5GHz smart meter. They probably know something about what not to use. i.e. Powerline modem. 2.5GHz is more standalize than