X10 IR Commands Do Not Have House Codes
Can the IR543 work with more than one house code?
How do I change the House Code on my infrared remote?
Unlike X10 radio signals, which have both a house and a unit code (like A9 ON,) commands sent from infrared remotes just have a Unit Code (like 9 ON). The IR543 that receives the commands adds the House Code. This means you could use multiple IR543 receivers with one X10 remote to control more than one House Code. Put the IR543s on opposite sides of the room and set them to different House Codes. You can select which devices you want to control by pointing your remote at the corresponding IR543.