Wondering if anyone might know if this might be able to be controlled via MODBUS TCP maybe? Its called a CTRL-DSP and its used to control an MVHR system. Just a bunch of buttons on the front panel to control it manually, was hoping to maybe control it via OH.It appears to be made by Logika and i’ve read that some of their boards are MODBUS TCP compatible, but i can’t find any info about this specific board.
There does appear to be an 8-pin header on there, marked MC2, could that be some kind of serial port perhaps?
In order to use modbus tcp you first have to get device plugged into ethernet network, then MCU has to be able to handle IP stack (which is true in most of nowadays cases). If you have 8 pins then it could be left for ethernet port (it uses 8 pins), but also some combination of few interfaces.
As far I know RS485 in its core is fine with 2 lanes (A, B) but can also work with third pin (A, B, GND) or 4 pins (A, B, GND, shield / A, B, A', B' - duplex mode aka RS422). Full duplex with shield and ground will be then 6 pins. Some devices have also switchable terminator resistor which you can quickly enable by connecting pins.
My advice - get official documentation and see what these pins are. Both modbus rtu and tcp are supported by openHAB.
You say “some of”… Definitely not this one, at least not out of the box. Because it doesn’t look having an Ethernet or wi-fi. But this M1 connector looks like it could be an rs485. May be an add-on plugs in here.
You can attempt to probe for it, but do to this without destroying your hardware you need some electronics experience. Which you, sorry, appear not to have, i am deducing this from your question. Plus, you need some software for a board, which is known to support modbus. Or documentation, because you need to know what to send in order to get a reply
At least you could make a passthrough device, which sits in the middle of the cable to the attic and allows to inject commands from a pc. The protocol can be reverse engineered, it’s most likely modbus RTU.
You can also check your main MVHR unit; good chance it has one more unused rs485 connector for integration purposes. I also have a ventilation unit, looks like this is how they are normally done.
Also note that your control box should be a modbus master, and attic unit is a slave. Modbus regisrers should basically reflect state of internal motors, valves, heaters, sensors, etc; it’s quite dumb; all the logic sits in the control box.
