x-10 Technology – The Low-key Protocol

09 Mar 2006

by Andrew Reed

Last December we described the Superna Home Automation system in the context of its convenience and ease of operation for homeowners and apartment dwellers. Now, for those who are neither techno-geeks or -phobes, but just interested and curious potential customers, here’s a somewhat closer look at the x10 protocol that’s one of the industry standards for operating automated systems.

x10 is a communications protocol. Unlike familiar protocols like TCP/IP that are used in sophisticated computer communications, however, x10 uses only one-tenth of one percent – 1/1000 – of the bandwidth needed for a dial-up connection. The system simply piggy-backs on the 60 mHz power of standard home wiring by sending a 120 mHz signal along the same electric lines. That limitation is also a benefit: x10 commands are slow, low-power, and very simple: “turn the radio off,” for example.

Here’s how the protocol works. An x10 system can have up to 256 addresses, devised by using the first 16 letters of the alphabet – A through P – and numbers “1” through “16.” An x10 controller is connected to your computer, and a receiver is plugged into an electric outlet (or a wall switch can be hardwired to the system).

You might give your kitchen appliances – dishwasher, coffee-maker, etc. – addresses beginning with “K” and ending with 1, 2, 3; assign “A” addresses to all audio system components throughout the house; and use “G” (as in, “Gee whiz, now I feel safe”) for your security system, including automatic locks, garage door openers, security lights, etc. If you want you can assign the same address to multiple objects, so that, for example, several lamps are turned on by a single command.

Each appliance is plugged into an x10 receiver, or, if your house is appropriately wired, into the wall outlet. Each appliance or group of appliances will now have a letter and number address. You control them through your “master switch” on your computer.

That simplicity allows x10 commands to be sent through existing home wiring systems without disrupting anything else. All appliances that are connected to x10 control devices (or through hardwired switches) receive every command to every device, but each appliance responds only to commands addressed to it. Thus, when you send a command – turn on the kitchen radio – to address A-7, that command is received by your lamps, garage door opener, and everything else that’s connected. But it’s ignored by anything with a different address, so (unless you’ve been careless in assigning addresses) you don’t have to worry about accidentally turning off the nanny-cam when you turn on the dishwasher.

Many devices are available that are compatible with x10 remote systems. As we described in December, the system allows you to centralize control over everything from lawn-sprinklers to comfort control thermostats and humidity sensors; security devices like motion sensors, security cameras, and nanny cams; and conveniences like lighting, washers and dryers, A/V, and home theater systems. You can even create a remote-controlled MP3 juke box.

When ATMs first came into use in the late 1980s, many people preferred to stand on line in the bank and do transactions the old-fashioned way. After using an ATM when the line was long and time was short, or in an “emergency” – being short of cash to pay a restaurant dinner tab – people began to like them. Many felt the same about online bill paying and automatic deductions to pay car insurance and other bills. But even people far from the cutting edge of high-tech life are finding it rewarding – even fun – to live in the 21^st century rather than the 19^th!

So even if you’re not quite ready to automate your whole house, try starting small by connecting one or two appliances: a pair of living room lamps, or a radio tuned to your favorite talk show. Then, as you get comfortable with the technology, you’ll be surprised at how quickly you want your system to grow!