I wanted to give an update on the XTB-232. There are a few beta units out there. One installation uncovered a problem with status reports from 2-way modules. The original beta firmware could receive standard STATUS_ON and STATUS_OFF commands, but not extended or preset-dim status reports. That is fixed now for X10 modules such as the LM14A. After I confirm it also works with a SmartHome 2-way module presently on order, the new beta firmware will be distributed.
The XTB-232 will be a “polite” transmitter. Not only will it wait for a clear line before transmitting, but it will also automatically abort and re-transmit a command if there is a collision with a command sent by a dumb controller such as the TM751. While that doesn't prevent corruption of the command from the dumb controller, the command issued by the XTB-232 should be received cleanly.
This may be an improvement over the actual CM11A because collision testing with that unit not only locked up the CM11A itself, but also the ActiveHome program. I suspect the occasional lockups that occurred back when I used the CM11A were also due to collisions.
The prototype XTB-232 has been tested running under ActiveHome, HomeSeer, and Home Control Assistant. Please let me know if there are other PC-based X10 control systems that I should also test for compatibility.
Jeff