
Getting Started
Software
Hardware
Installing Modules
Troubleshooting X10
Voice Recognition
Configuring it
The Gadgetry
Web Control
Setting it up
Cameras and Surveillance
Installing Cameras
Software
Heat/AC Control
Hooking up the furnace
Sensing
Weather/Environment
Gathering Data
Getting Info From the Internet
In order to determine which module turns on or off when a command is sent, X10 uses a series of House Codes and Unit Codes. These are set on the module itself, usually using dials (some of the smaller modules are set using a combination of button presses and pauses--check the manual if you're not sure). There are 16 unit codes (1-16) and 16 house codes (A-P). These are combined to identify a certain unit. For example, you could set the unit code dial on a lamp module to 2 and the house code to A. If you sent the command A2 ON using Powerhome, the lamp would turn on. By combining house and unit codes, you can have 16*16, or 256 different modules in a house (assuming your neighbors don't use HA).
It's a good idea when installing a system to keep track of which code combinations you're using. That way you won't overlap, and if you need to reconfigure your software, you'll remember which codes go with what. I use Google Spreadsheets to keep track, since I can then access the file anywhere.