Hi Guys
Wow! thanks for all the info, I'm gob-smacked at the complexity of some of the applications, but agreed, if you want that level of addressability and control it's needed. I just wanted to turn the geyser on/off and one light!! so I will get inspiration from the circuits particularily the mains interfaces, and just use some simple PPL tone switching at 2 different frequencies, the didtances are pretty short and I should mangae without zero crossing detection or phase control etc and just stick to a simple go on/off to 2 devices. I'll give X10 a miss and just output a high on a pic port to turn on the PLL. But thanks a ton for the info.
Graham