Please indulge me the long post -- I'd like to explain my situation as thoroughly as possible. Hopefully the experts can reassure me that I'm on the right troubleshooting track, and other "newbies" like myself can see that it takes more than "plug & play" to get X10 working as advertised...
I'm using a DS7000 security console on House code J. When I add in the MS15A, I did
NOT specify it as a transceiver for house code J. (If I did, I run the risk of repeating commands and potentially causing powerline collisions, right?) So, with this setup, I have two sources of powerline commands -- the DS7000 ("transceiving" the RF commands) and the MS15A (sending AHP-generated commands).
Now, if these two devices are on opposite phases of my house wiring (i.e., DS7000 on phase A, CM15A on phase B), I can see how some modules would operate from remote control but not from AHP, and vice versa. (This is, indeed, happening.) In fact, if the two phases were completely isolated, I would expect RF commands to control all modules on phase A (since they are transmitted by the DS7000), and AHP commands to control all modules on phase B (since there are transmitted by the CM15A). However, I have a bunch of modules that work from BOTH command sources.
So, even though some commands seem to be crossing phases, I figured that a SignaLinc signal coupler plugged into my 240V dryer outlet couldn't hurt, right? Unfortunately, this did not solve my problems. So, after reading through EL34's very thorough "Fixing your X10 problems..." posting and website (
http://www.el34world.com/Misc/home/X10_0.htm), I'm going to try an "active" plug-in coupler/repeater next -- hoping that this will strengthen the X10 signal enough to reach all of my modules. I don't have ANY available space in my main distribution panel to add circuits for a hard-wired coupler/repeater without replacing the entire panel. Hopefully, the plug-in coupler/repeater will be my magic bullet. I'll respond with the results of that test next week.