256 Possible Addresses
Since there are 256 possible addresses, am I limited to 256 controlled devices?
No. There are 256 individual X10 addresses--A1 to P16--to allow you to control a large number of devices. In most homes, there are a number of lights that are always turned on around the same time of day. With X10 modules, each light could be assigned an individual address, but turning on a number of lights individually would take some time. Instead, all of the lights could be set to the same address. That way, only a single command is sent to turn on the group of lights. Grouping modules together also removes the limitation of 256 total.