Appliance Control: Making Things Do Stuff - Smart Home Automation with Linux and Raspberry Pi - page 7

Figure 1-1. The LM12U lamp module, 122 × 52 × 42mm

This will support any incandescent lamp between 60 and 300 watts and can be switched on and off or dimmed by
any X10 controller set to the same house code. The LM12U has a sister device, the AM12U, which works in the same
work. The primary difference is that the AM12U is intended for appliances and therefore ignores any “dim” messages.
The LM12U will also respond to two special messages, “all lights on” and “all units off,” provided they are sent using
a matching house code. This module, like many of the others featured here, is placed in series with the power line
acting like a logical AND gate. That is, both the lamp's switch and the power switch at the wall must be on for the X10
“turn on” message to have any effect.

N The code numbers given here are for the U.K. versions of these devices. Because of slightly—but
significantly—different power systems used in various countries around the world, alternate modules are required
according to your country. The LM12U in Italy, for example, is called the LM12I.

Note