I would be curious to see some photos of the PCB you have in your unit to see what port your using.
On the Vent Axia Sentinel Kinetic I’m using, the BMS port (RJ9/RJ10) is connected to a MAX232 equivalent chip, and is used to connect a remote 1602 LCD display over RS232 communication.
There is a RJ11 port I’ve not been able to identify it’s purpose yet, and an unpopulated RJ45 that connects to a TTL UART of the MCU
If the VentAxia device uses CANBUS that would be amazing, I will investigate this in a week’s time.
In the meantime time I’ve been building a remote display with a ESP8266 to make steps towards adding ESPHome support over serial
Needs a couple of fixes (display is rotated by 180 and the MAX3232 prevents programming without the addition of an inline resistor) before a second batch is made, but it works
following this project with great interest I will try to add my bit to the puzzle as well.
There is a company called Regulus in Czechia which is selling rebranded Vent-Axia units. They have a whole suite for home automation which is based on the PLC. Now, they are offering a module that will connect to the Vent-Axia board and will take control over it. It then uses CIB for the communication with PLC. Here are the links to the official connection manual with some schemas. Its in Czech unfortunatelly but you can translate it via AI
How does that even work to set the Summer bypass, read the temperature and know the mode of the unit?
The output the the MVHR is 0-10v on a input pretending to be a CO2 sensor, and the output is for the error LED.
I don’t know how they could get that info or set summer bypass with that control system
Not according to the PDF firing guide for the unit listed above. Just connected to a 0-10V line for fan speed conteol, and the LED ouptput for warning feedback
We are working on it, to connect to the vent axia sentinel kinetic BH and Plus by emulating the display, and then programatically entering into the system by simulating button presses.
This way, while crude, should allow for setting summer bypass mode, fan speed, and even reading the temperature and humidity (By reading from the Development menu)
I will try to add my bit to the puzzle as well.