The IR543 can control units 1 through 8, and all lights on/off using the buttons on the IR543. However, it can also transceive all 16 unit codes from IR to X-10 power line signals. In other words, the Pronto or other remotes that transmit X-10 IR signals, can use the IR543 to control all 16 unit codes on a single house code. The X-10 CCF files on this forum will allow the Pronto to control all 16 unit codes through the IR543.
RCI Automation[Link: ourworld.compuserve.com]