Frequently Asked Questions - X-10 Technology

This page contains answers to frequently asked questions about the X-10 technology. Please feel free to browse the message board for answers to more questions.

What is X-10?
X-10 is a power line protocol that allows commands to be sent over your power line to control electrical devices. Special control modules are used to send and receive these commands. The device modules are addressed with a letter and number code. There are a total of 256 device codes available. Each module may be set with its own unique address using a letter in the range "A'->"P" and the number "1"->"16". You can automate all your lights and appliances without running a single wire! There are 16 commands that may be sent to devices. The most common commands include "ON", "OFF", "DIM", and "BRIGHT".

What's so great about X-10 anyway?
The best thing about X-10 is that it's inexpensive. Device modules can be had for less than $10.00. Table top controllers are less than $15.00, and the computer interface is about $49.00. See the links page for a list of X-10 distributors.

What's not so great about X-10?
The biggest problem with X-10 is that the protocol is not reliable. What this means is that there is no guarantee that the "ON" command you sent the table light really got there. Sometimes commands get lost, and you never know what happened. If two commands are sent at exactly the same time, they could collide on your power line, and they will not reach their destination. If you have a large home, the X-10 commands transmitted by the computer control module may not be strong enough to reach all your devices. You may have to install an X-10 amplifier to solve this problem.

The bottom line here is that it's best to test out your electrical system with just a few modules and see if it works OK.

Some of my modules don't respond at all to X-10 commands, but some do. What's going on?
If your home is over 4000 square feet, you should probably install an X-10 amplifier. If not, you may get away with an X-10 bridge. Your home is wired from the power company with two phases. The power arrives at you electrical panel via two big fat wires. The voltage across these wires is 220 volts. One wire runs down your electrical box on one side, the other down the other side. Thus one wire supplies 110 volts to one side of your house (or half your outlets), and the other, the other side. X-10 signals are only fed into your system through one side (a single outlet), so for that signal to get to any X-10 device on the other side, it needs to go out to the transformer on your electrical pole, then back in the other side. That's a long trip, and it's a wonder it works at all. To fix this, you can add an X-10 bridge between the two phases, that essentially couples the two phases and allows X-10 signals to pass.