I'd like to thanks all who posted in response to my question, all very interesti
ng!

The goal of my project is to make an net of PICs (mostly keyboard and LCD displa
y) communicating to an master in the roof (no display or any button).
This is for simplifying the connections between the devices, wich has to be "non
 invasive"
to the existing wires of the house, to make installation easy to anyone!

So, i think that a pair of cable or the AC outlet is the best way to work with.
Speed is not a problem, since data can be exchanged with the points at a rate of
 150-300 bps or less!

My questions are about the polling within stations and collision avoid.

I'll be glad with your replies!

Thanks again!

Silvio B.
ssj@unorpnet.com.br
ICQ:2221034