stevenhanna6 wrote:Hiller, I dont know who should do what right now I need the equipment first to play around with. Looks like CM11a is the way to go, as far as I understand it works with both RF and over power lines.....does it do 2 way communication for both?
The CM11A is effectively a bi-directional RS232 serial to X10 convertor. It also has an ability to store some macros internally that can act as a mini controller/scheduler although often people avoid this and drive their system purely via the serial port from a PC application like ActiveHome or HomeSeer.
The CM11A can both send and receive X10 signals on the house wiring but it will not receive or send any RF (radio) signals - you would need the RF transceiver for that - but they are low cost. These products have different numbers in the UK so I am unfamiliar with the US models here
X10 was originally a transmit only (command) type of system but was enhanced to add status reporting of devices. Only some devices support status reporting and in the UK variants almost none
. However using xAP you can ask for the status of any device as it tracks commands to know what state a device (should) be in. If it is changed locally eg turned off at the switch this could be wrong though.
Also worth mentioning is that X10 is somewhat slow and sending the command to turn a light on takes a couple of seconds, dimming a light to say half brightness can take considerably longer. X10 is a little 'old hat' technology wise and over time it has had new features shoehorned into an awkward model, but it still has several great advantages - it is very low cost - pervasive, and also totally retrofit meaning you don't have to run cables anywhere. The protocol lacks sophistication by todays standards though and various X10 products work in different ways even sometimes within the same labelled product manufactured by different manufacturers ..
X10 is a great entry product to HomeAutomation though and remains my recommendation for all new people experimenting in HA. It illustrates the possibilities and concepts and helps people understand what is critical in their own HA setups. The shortfalls of the product are often outweighed by the accessibility and cost. You can choose anything from X10 at the low end through mid range solutions like C-Bus, Dynalite etc to hugely expensive Crestron/Lutron/AMX solutions at the other extreme - but you won't be taking under $10K at that end. For example in some applications a 2 second delay to turn a light on is fine ( an ouside light on a timer or dayligt sensor would be ideal ) however for other applications it can be awkward eg triggering a light from a PIR movement sensor as you enter a room .
Kevin