i tried the rj45 port and also the other one, that does mention modbus bellow, but instead of A B 0 it has D1 D0 COM…
can you just tell me if your board is similar to mine ?
Also any idea what that female USB port is for ? (maybe a wifi pen )
It seems that I have a earlier version of the board. Mine is showing A B 0…
And doesn’t have the female USB port.
Second connector down on righthand side is marked for A / B / 0 (and 12V).
I think you’re on the wrong connector.
The D0/D1 connector might be RS232 Modbus port or suchlike.
No the D1 D0 COM connector next to the RJ45 is the good one. As you can see below the connector it is marked as Modbus.
And it corresponds with the board description given in the manual.
@Paulo_Fernandes have you any progress? I’m also trying to connect it, but I had a stupid misconception. I thought I wouldn’t loose the remote so I gave up when the remote got disabled. I’ll try again. I’m using a USR device and will try to connect D0, D1 and COM.
Also, I see the remote is connected to a socket with A, B, 0 and 12V. Isn’t this also modbus? Couldn’t we just clip to the A, B, 0 cables? From my experience, modbus should have no problem with that (if it’s also modbus).
i gave up, because after many tries, with different adapters and apps i never got anything , then i noticed there was a page inside the manual box, that was an adendum to the main manual, it changed one thing only: next to modbus it says “disabled in this version”
i also tough that the remote seems to be connected to a modbus port, but i had no courage to try it, the machine is a bit expensive 
There is also the RJ45 connector to investigate.
I did it! 
For reference, I’m using a usr-wifi232-630 device, connecting to D0, D1 and COM (I’m not sure if D0 is A on my device or the opposite). I set the jump JP1 and use ModbusTCP<=>ModbusRTU mode.
I was almost going to give up but then (by my experience with modbus) I set retry every second, and the device started to reply on second request (first request is like a wake up, it will never respond).
I can see baudrate, and other stuff that I can confirm it’s real data. I’m now going to try and start it as I already found the air flow speed.
I used RJ45 connector in the past with other DIN rail modbus devices but from what I understand, there’s no standard in the port, so it should work exactly the same (it should be RTU, not modbus TCP).
Yes, the serial RJ45 pinout is in a picture further up this thread.
I seem to be able to read everything I want and I was able to even see where to change “speed”, but I don’t see how to turn it on and off. Does anyone know how?
A ventilation is not supposed to be switched off at any time. So there is no ON/OFF.
Only thing you can do is to select a configuration with Stand-by mode and but it in stand-by. See here: OpenHAB_VMC_modbus/DOMEO_PARAMETRES_MODBUS-03_2016.PDF at master · FaBienPi/OpenHAB_VMC_modbus · GitHub
My ventilation system is optional, I don’t have it turned on in some part of the year. But I understand what you mean, I thought of that, I saw standby on and supposed it meant the machine was “paused”. I’m going to try and swap that value to see if it works. Thank you
Hi Diogo, can you tell me what software you used and what model ? You manage to connect using the modbus port or the wired remote one ?
Hi Diogo nay chance that you can give me some tips about how you did it and the exact model you have ?
Hi Paulo, I didn’t receive any notifications so I was unable to reply. I was using my own code written in node.js to communicate over modbus TCP. The hardware is a PUSR module (look pusr.com) which has a mode in which it convert RTU to TCP and vice-versa.
Hi! Did any of you finally get it working? I have a domeo 210 FL 3V EU and would like to do the same. Thank you in advance!
Hi Diogo! Did you get it working? What model do you have? (I have DOMEO 210 FL 3V EU) I’d appreciate if you could share the code you used and some details about the process so that I can also try it out! 
I’d appreciate it a lot! Thank you in advance!