House code letters? What is the purpose?

[Jeremyj]

I am going to use about 9 window-door sensors, a couple of motion sensors and a couple of light modules. I understand the unit dial has to be on the same # as the console, but is it ok to have 2 window sensors on the same house letter, for example, the front and back door or two doors that are near one another? The house code letters only communicate with the Voice Dialer Console (PS561) to tell you where there has been a security breach, right???

[Brian H]

Not exactly. The house code has to match the house codes set on the Lamp Modules and Motion Sensors not of the Security Type.
The House Code in use will also allow the master remotes non security keys to turn on and off the lamp and other X10 modules you may have if they match the house and unit code address.
Security Motion Sensors, Security  Door/Window Sensors and the Security Remotes all have to be registered with the console and do not use the standard House Code/Unit Code Address.