X10 CM11A signal strength.

123

Senior Member
This question is for old school X10 users who pulled out a lot of hair getting their X10 systems halfway reliable. :)
 
I've been using X10 SmartLinc switches for many years and they've been reasonably reliable ('good enough'). However, there are a few that are persistently unreliable and I've long given up debugging them. With a CM11A, they'll rarely act on the transmitted signal. If you hit the jackpot and get one to turn on, you won't get it turn off. For X10, those switches are in Outer Slobovia.
 
Having said that, there is something that does make them work reliably. If I use a Maxi Controller (SC503; the brown box with many buttons) it can control those Outer Slobovian switches very reliably. Clearly, the Maxi Controller sends a stronger signal than my CM11A (both plugged into the same outlet).
 
Has anyone else experienced this? Is your CM11A the weakest transmitter of all? Or is my CM11A degrading?
 
 
 
I'm aware of the XTB-232 which has a good reputation for producing a very strong signal. However, I hesitate to part with $109 to fix some old-tech X10 switches. It would seem to make more sense to spend money on expanding the number of UPB switches I have (which work very reliably for me).
 
I'd get another CM11A if I knew it would perform better and not just duplicate what my current CM11A does.
 
Been testing the CM11A (a few of them), TW-523 and XTB11R along with leaving an old Elk X10 signal meter on line. 
 
I used to use the XTB amplifier and have removed it from the mix above.  It was working fine before removing it.
 
Current updated configuration has the above mentioned controllers hanging off the fuse panel on separate breakers.
 
Have switched over to Linux now for automation and use of Digi 8 Port USB to Serial controllers (used these with Windows for many many years).
 
I have not had any recent issues testing about 5 CM11A's (old ones) here and did not see any signal differences between the CM11A's.

Tested using Homeseer and HeyU in Linux and X10 branded Appliance and Light switches and outdoor Black and Decker Free Wire modules.  (light switches originally went from X10 to Insteon then removed).
 
As temperatures have climbed here in the midwest seeing on an off noise as I did last summer.  More than likely it is related to noisy or starting to go bad compressor motors maybe which does ding X10 signals here occassionally.
 
So when you look at why a technology doesn't work, you need to learn about how the technology operates. X-10 is an old technology, obviously, and communicates by sending tones on the powerline. Back when it was invented, it was quite reliable, but the things we plugged in the outlet were much simpler. Incandescent lights, fans, irons, butter churning machines :)  so the signal went through. But today its more complex, and MANY things you might plug in the wall block signal, and filter it out.  The list is so long today that its not worth even listing. 
 
But first of all, do you have a coupler in your breaker box to better couple one phase to the next?  If not get one.  Will a new CM11A help? Likely not. Will switching to UPB help. Definitely, it works different than X-10, BUT you still need to deploy it carefully and use a coupler or even better, an active repeater.
 
So for your problem, it comes down to just unplugging devices from near where it doesn't work, and you will see when you unplug one, things start to work. Maybe a microwave, TV, UPS power supply, you name it. Then you can buy X-10 filters to plug these devices into, but it becomes a game of wack-o-mole. If your cheap, that is the solution. If you really want to fix it, switch to UPB and deploy it correctly, and it will just work.
 
@Pete: Thanks for the info that you saw equivalent performance for 5 CM11A units.
 
@ano: I have a Smarthome SignaLinc Repeater installed (Model 4826A). Even with it unplugged, the Maxi Controller's signal will get through to Outer Slobovian switches whereas the CM11A won't with (or certainly without) the repeater.
 
 
I understand the issue of X10 being old tech and susceptible to noisy devices and signal-suckers. However, I have the situation where one transmitter (the Maxi Controller) reliably gets through to Outer Slobovia whereas the other (CM11A) doesn't. So there are hurdles for the X10 signal to surmount but they're not very high because the Maxi Controller gets over them easily.
 
What I need is a CM11A with the performance of the Maxi Controller. Maybe a new CM11A has this kind of performance … or maybe not and the Maxi Controller is just a better performer. I had hoped someone has observed this difference and could confirm/deny there is/isn't a performance difference between the two models of transmitter. 
 
It's frustrating to watch the Maxi Controller reach every X10 device in the house (meaning it encounters no insurmountable line noise) whereas the CM11A's reach is considerably shorter. I guess I have no choice but to lower the noise floor by turning off a bunch of breakers to try to isolate which device (if any) is creating hurdles for the weaker CM11A.
 
saw equivalent performance for 5 CM11A units
 
Many hot spares collected here (same with UPB) just in case.  A couple of the CM11A's did get a bit warm when testing (not hot though).
Thinking there are more TW523's here than CM11A's (cuz of the OmniPro 2 panel I suppose).
 
As Ano mentions above check out the X10 old filters and dual phase bridges. 
 
Have a few different old Radio Shack controllers (thinking one is the Maxicontroller)and BSR which I have used plugged in to different outlets around the house...watch the debug logs on a tablet or laptop which I wander around the house with the manual controllers.
 
The old TW-523 combo with the Ocelot also works well for me.  I have left it in place but do not utilize it today.
 
Jeff Volp's stuff is a steroidal injection and cleansing of X10 should you decide to utilize it.  He has added a new XTBII now called the XTBIIR (repeater).
 
Here is the debug I watch with Homeseer ...slower it is the noiser the power line is.
 
Jun-20 3:17:19 PM           Starting Plug-In     Initializing plugin X10 ...
Jun-20 3:17:21 PM           Info     Initializing CM11A/12U on COM port /dev/ttyUSBX10
Jun-20 3:17:21 PM           Starting Plug-In     Plugin X10 started successfully in 1436 milliseconds
Jun-20 3:17:49 PM           X10 DEBUG     CM11A.SendIt(): Sending 2 bytes: 0x4 0x66
Jun-20 3:17:49 PM           X10 DEBUG     CM11A.SendIt(): Data sent, waiting for checksum From CM11a...
Jun-20 3:17:49 PM           X10 DEBUG     CM11A.SendIt(): Received a good checksum: 0x6A
Jun-20 3:17:49 PM           X10 DEBUG     CM11A.SendIt(): Send 0x00 to CM11a (command to transmit the data onto the power line).
Jun-20 3:17:49 PM           X10 DEBUG     CM11A.SendIt(): Got ack of: 0x55
Jun-20 3:17:49 PM           X10 DEBUG     CM11A.SendIt(): Success! 0.498 seconds for CM11a to send.
Jun-20 3:17:49 PM           X10 DEBUG     CM11A.SendIt(): Sending 2 bytes: 0x6 0x62
Jun-20 3:17:49 PM           X10 DEBUG     CM11A.SendIt(): Data sent, waiting for checksum From CM11a...
Jun-20 3:17:49 PM           X10 DEBUG     CM11A.SendIt(): Received a good checksum: 0x68
Jun-20 3:17:49 PM           X10 DEBUG     CM11A.SendIt(): Send 0x00 to CM11a (command to transmit the data onto the power line).
Jun-20 3:17:50 PM           X10 DEBUG     CM11A.SendIt(): Got ack of: 0x55
Jun-20 3:17:50 PM           X10 DEBUG     CM11A.SendIt(): Success! 0.007 seconds for CM11a to send.
 
123 said:
It's frustrating to watch the Maxi Controller reach every X10 device in the house (meaning it encounters no insurmountable line noise) whereas the CM11A's reach is considerably shorter. I guess I have no choice but to lower the noise floor by turning off a bunch of breakers to try to isolate which device (if any) is creating hurdles for the weaker CM11A.
No I don't think you have it. "Noise" and signal reduction are NOT the same thing, and "lowering" the "noise floor" likely isn't a problem.  Certainly X-10 noise can exist, but constant X-10 noise is quite rare. Usually you just see temporary noise. The biggest problem is signal sucking where devices on your powerline filter out the X-10 signal, because to them, the X-10 signal looks like noise.  Also, there is no "noise floor" as if some noise is the same all around your house. It isn't. 
 
Unless you know for a fact that you have noise, that probably isn't your problem.  Certainly fix noise if you know about it.  But if signal is not where you want it, then it most likely caused by some device greatly reducing your signal.
 
Also one other thing. If your X-10 is old, I have seen old X-10 transmitters malfunction where they fail and constantly send some bogus X-10 signal over and over, and this "noise" stops some devices from working.  X-10 signals usually take three parts, the letter, the number, then ON or OFF or DIM.  A constant "B" or "12" over and over again causes havoc. 
 
I know of nothing that will boost the CM11A, a second one closer to the troublesome modules might work or might make it worse. If 2 X10 devices send at the same time (not 100% in sync) then the signals will probably get garbled.
 
As another poster noted, you have a problem with signal suckers. You can try to isolate them but pretty much everything made today with a switching power supply can be a signal sucker. As devices age (X10 and Insteon modules also) they become larger signal suckers. It's one of the reasons I've moved away from power line communications.
 
@ano
 
Please specify where I said noise and 'signal sucking' were the same thing. I never did and I even bothered to mention both terms because I know the readership here tends to zero-in on these things. Nevertheless, one shorthand use of 'Noise floor' was sufficient to get a drubbing that "No I don't get it". Such is Cocoontech.
 

Unless you know for a fact that you have noise, that probably isn't your problem. Certainly fix noise if you now about it.
I'll know after I investigate by switching off breakers and bringing them back up, one by one, to identify which circuit (if any) contains one or more devices causing the problem. It may also be due to the cumulative effect of devices on multiple circuits. Until I gather more information, I don't know the specific source of the problem. It could be those Outer Slobovian switches, all the same model (23885W, have grown old and become hard of hearing.
 
What seems to be glossed over is the fact that only the CM11a is thwarted and the Maxi Controller works first time, every time ("Damn the noise and signal suckers, full speed ahead!"). Clearly, the two devices are not performing identically … and I still don't know if that's the norm or if my CM11A has degraded.
 
 
@linuxha
Thanks. I tried moving the CM11A to an outlet within 5 feet of the breaker panel and that permitted it to turn on some of those Outer Slobovian switches but it was hit or miss for turning them off. I concluded the meagre performance improvement was not worth the effort of running a new cable to relocate the CM11A. It's currently located farther from the panel (and on a dedicated circuit). Meanwhile, the Maxi Controller works when plugged into to just about any outlet in the house (wish the CM11A worked like that).
 
I'm OK with powerline communications; the UPB switches I have work fine (undoubtedly benefitting from all the work I did to pamper the more fragile X10 system). 
 
At my old house, I struggled getting a reliable signal with a CM11a on my HomeSeer computer, and a TW-523 from my Ocelot.  I finally purchased a signal strength meter and did the breaker test.  I also installed a signal/coupler in my breaker box (can't remember the brand, but I do have a spare one i believe, even went through different brands until I found this one that worked).
 
You would not believe the devices that caused signal sucking (night lights, monitors, computers with cheap power supplies, etc...).  I then purchased a bunch of signal blocks and started putting them on my plugged in devices.  all of this is mentioned above in previous posts.  This is the 'only' way to get reliability, but once it is done, the commands are pretty consistent and the system performed well.
 
I experienced the same thing you are with the plug-in Maxi controller, it would always work.
 
I do have a bunch of my old X-10 for sale from my previous house.  I believe I may also have signal/coupler and possibly another CM11a in my closet.
 
BraveSirRobbin said:

I experienced the same thing you are with the plug-in Maxi controller, it would always work.
 
Thanks for the confirmation.
 
 
I shut off all breakers, brought them up, one by one, and identified a circuit that, when off, allowed the problematic switches to run properly. When the circuit was enabled, the problematic switches could no longer be controlled. The circuit in question has 4 SwitchLincs on in … so there's not much I can do about their attenuation.
 
Long story short, I replaced the CM11A and the problematic switches are now controllable.
 
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