But I can see a clue: I have an XRB-ANR noise blanker; I think it is detecting what the issue is: very repeatably, on about 1 second cycle, there are 2-4 blips of the LED. Very consistent. I am convinced these are the things causing the XRTB to repeat and blanket my power line so NOTHING works.
Sorry I'm late to this party. The Forum has been pretty quiet recently, and I no longer check in every day. If anyone has a problem with any of the XTB equipment, certainly email me. I normally respond to an email within hours if I'm available.
The P house code is only used for programming the XTBR mode options, and it takes a special sequence to access them. Ordinary P ON and OFF commands are ignored. So there is no problem using the P house code for an installation.
The XTB-ANR does not transmit anything, and cannot cause the XTBR to do anything. The "2-4 blips" indicate you have powerline noise. That is the background noise monitor included for free in the latest XTB-ANR firmware so you have an indication of what the noise level is. A low noise environment would be just one brief flash every cycle. Three very brief flashes indicate the noise is at the threshold where it can begin to effect X10 operation for devices that do not include AGC to raise their detection threshold above the background noise level.
Above 3 brief flashes the XTB-ANR will begin to attenuate the background noise. In that case the flashes become much more obvious to indicate it is turning on the attenuator. I have a Lumoform LED light that pumps out a horrendous amount of noise, and causes the XTB-ANR to flash almost constantly as it is trying to attenuate that noise.
80mV of noise is a serious problem!
The CM15A is a polite transmitter, and will abort a transmission if it recognizes a collision with an existing X10 command. Noise near the X10 carrier frequency can be perceived as an X10 signal. So what I believe is happening is that the CM15A keeps trying to issue a command, but aborts them due to background noise. The XTBR transmitter has a turned circuit that can increase the level of in-band noise just like the tuning circuit in an old time radio allowed it select radio stations. Its LED is flashing in response to the corrupted commands from the CM15A.
In any case, you have a very serious noise problem. You will have to track down the source and either replace it or isolate it with an appropriate filter. Prime candidates are small plug-in power modules and CFL or LED lights. Large appliances with variable speed motors, such as newer HVAC blowers can also be serious noise sources.
Since you already have a Monterey, use it to track down the noise source. Once you remove that your system should behave much better.
As a further thought, if there is another repeater in the installation, you may be experiencing command ping-pong. In that case mode option 16 must be turned off if you just want to use the XTBR for direct boost (no repeat). If you do not have another repeater, the XTBR should be located adjacent to the main distribution panel to be most effective.
Jeff