Steve,
The M1 will support "most" all X-10 devices by using the PSC05, two way module (TW523 is consumer number), or the PSC04 one way module which is plugged into the M1 or EZ8 via a RJ11 telephone type cable. Make sure you note in the instructions the way the cable must be made. If it is backwards, it will not work. There is a 50/50 chance of being backwards. Normally with the PSC05 you have to furnish the cable.
The M1 will support many other advanced lighting systems including UPB. The M1XSP acts as a protocol translator from the M1's generic lighting commands to the specific system you are connecting to it such as UPB. You set the jumpers on the M1XSP according to the lighting or thermostat type you are connecting to it.
In the Rule Engine all the lighting commands are the same, no matter what lighting device you have connected to the M1.
One further thing to remember. When setting up a lighting device in ELKRP Lighting menu, make sure you use the format of "Serial Port Expander" when a lighting device is connected to the M1XSP.
UPB requires a System ID that is set in the Global Programming.
The M1 keeps an On/Off mapping of all lighting devices that it can hear so that you can write Rules using the state of lights.
Example: You could write a rule that if you turned the kitchen lights on and off 3 times within 10 seconds, the alarm would disarm... etc.
ELK Products Website has some good M1 application examples that are part of the ELK newsletter. You may want to sign up for the FREE newletter.
Have fun and if you have problems, we are here to HELP.
ELK Swat Team
No BUG is safe!