[solved] Somfy RTS reliability problem

[phitar]

I used to have a Somfy Tahoma and could reliably (for 3 years) close all my 18 rolling shutters at night and open them in the morning. I now have a scene in Domoticz to open and close all of them. I disabled the Tahoma about 3 months ago.

I find now with Domoticz sending a command through RFXCom that every now and then, one or two shutters won't receive the command. This happens quite rarely, at least 2 problems with a shutter not closing a month but there is an issue. Not sure if it is timing, power, range... or else. It is much harder for me to notice a problem with opening as they don't all open at the same time.

My house is not very large and in wood, I never had an issue with the tahoma or RTS remotes, the RFXCom transmitter is quite central. It is not always the same shutter that fails to close so I am convinced sending the scene command again 5mn later would fix the issue. I have tried to analyse the problem before reporting it but I can't.

Is there any test I could perform to help debug this ?

[nayr]

sounds like RF interference, Somfy (~900Mhz) and RTXCom (~300-400Mhz) operate on different bands.. there may be some occasional interference on this band that your previous system did not encounter.

external interference can be difficult to overcome, might try a duplicate schedule offset by a few mins, if the first command is jammed out hopefully the second one will be fine.. a lua script could re-issue the last command after 5mins automatically.

[jannl]

I think interference could be the problem. But my somfy and rfxom both (same sending hardware) operate on 433mhz.

Not sure where you got your info.

Do you may be send more commands at the same time? Do you use a kaku relay transmitter?

[b_weijenberg]

phitar:
Are you controlling all motors with the same ID - Unit Code so that only one command has to be send?

If you control each motor separately using a unique ID - Unit Code you have to transmit 18 commands. I can imagine that if 18 commands are transmitted too fast after each other that a motor cannot interpret the code correctly.
Maybe it is a solution to add one ID - Unit Code to all 18 motors so that you can control them all by only one command.

[phitar]

b_weijenberg each blind has a different ID, this way I can control them according to different scenarios
I used to control the same setup with a Tahoma (Somfy's solution) and never had a problem. Again each was controlled separately.
Controlling them all with a single command defeats the purpose of home automation

I am sure I can find a way to circumvent the problem but I believe fixing it properly would benefit the community

nayr, I believe RTS in Europe is on 433MHz. You are probably thinking of IO Homecontrol or ZWave which Somfy also supports and works on frequencies just below 900MHz

janni, no Kaku, just plain RFXCom and Domoticz on a Raspberry

[b_weijenberg]

The RFXtrx433E transmits the same commands as the Somfy RS485 RTS transmitter.
I have not tested the Tahoma but this device transmits maybe repeated commands.

You keep of course a unique ID in each motor. You add also a general ID in all motors so that the motor can be controlled individually and also all motors at once with only 1 command!

[bizziebis]

You can indeed add one ID to every single motor and use that to close/open all blinds at once. I also do it that way. But I also have every blind as a separate switch in Domoticz for when I need more control. You can add the 'master switch' as a slave to all separate blind switches so the status will also change accordingly.

There is also another benefit of this solution. Your blinds will all close synchronized instead of with seconds of delay

[phitar]

Indeed it is a possibility to have a single command. I actually cannot do this as I have multiple windows that have two side by side blinds. When both come down at the same time (from a single command), there is a resonance that blocks one blind before the bottom regularly. This does not occur when there is even a tiny gap.

At any rate, another possibility is to double the command, to have a replicated call moments later.

The thing is I think the domoticz+rfxcom solution can be improved because
1. the problem is random (blind with issue) and not that rare
2. tahoma (Somfy's home automation solution) does not have the problem (it has plenty others mind you, not the least being closed)

It may be a timing issue (interval between commands), command timing, ... or something is missed in Domoticz sending the commands. I don't know. How can I help debug the issue so that everyone's RTS solution gains in reliability and robustness ?

[phitar]

Just to be clear, I appreciate the suggestions on how to work around the issue but I think there is a bug that could potentially affects all people relying on domoticz to close their blinds for security.

This morning I tried shooting a video of the blinds blocking when coming down at exactly the same time but did not succeed... It is probably too cold today.

[phitar]

So the problem still manifests itself.
Today, opening 5 blinds in quick succession, clicking manually, one of them did not open even though domoticz showed the "open" icon, confirming I had clicked the button properly.

[b_weijenberg]

Please contact support rfxcom.com

[b_weijenberg]

The problem was not so evident. It was not a range problem and because the RFXtrx433E has 2 transmitters, one for 433.92MHz and one for Somfy at 433.42MHz it could not be a problem in this area. With the help of the user we found that the problem only appeared when transmitting a large number of commands fast after each other on a fast system. When transmitting a large number of commands fast after each other they will be buffered in the RFXtrx433E. Some Somfy motors do not accept RF commands when transmitted fast after each other.
This problem is solved in firmware version 1002.

There is still a risk that a Somfy motor does not respond on a command. The RFXtrx433E transmit only a few RF packets which is required by some Somfy motors. If another 433.92MHz RF sensor transmits a lot of spurious or a Somfy sensor transmits at the same time the RFY packet is not received.
If you experience this problem you can repeat the RFY commands in Domoticz.