Wireless controllers and switches
Power line communications requires a power line connection, of course. It’s inconvenient to walk around trailing an extension cord, which led to the creation of modules that let wireles devices interact with X-10 networks. The X-10 model TM751 Wireless Transceiver Module provides the interface between wireless units and the power line network, receiving wireless signals and generating the appropriate messages onto the power line.
One restriction you need to keep in mind using the TM751 is that, although you can select the specific one, the device only responds on a single house code. That’s an advantage in applications where you have a large area to cover wirelessly. At most, you’re only going to get approximately a 100-foot range between a wireless transmitter and the transceiver, and the range can be severely reduced by intervening metallic surfaces. You can usually solve the range problem by adding more transceivers, but you’ll want them on different house codes to ensure they don’t both receive a transmission and output to the power line.
Two alternatives to the TM751, shown in Table 1-4, give you some other options. The Smarthome All Housecode X-10 RF Receiver works at longer ranges, and can be programmed through your PC to operate on multiple house codes. The Smarthome X-10 RF Receiver to RS-232 Adapter gives you a direct wireless interface to your PC, giving you more options for wireless control of software such as HomeSeer.
An interesting problem you can solve wirelessly with X-10 control is putting a switch where there presently are no wires. The Smarthome X-10 Wireless Wall Switch enables you to do that — it looks like a four-element wall switch, but instead of wiring into a switch box in the wall, it transmits wireless codes to a nearby transceiver. You can let the transmitted codes control X-10 lamp or switch modules directly, or you can receive the transmission at your PC through a controller and execute any actions you desire.