› M1 Support Forum › Questions about moving from HAI OmniStat to Aprilaire 88xx › Reply To: Questions about moving from HAI OmniStat to Aprilaire 88xx
November 30, 2022 at 1:30 pm #6522
I don’t know if the 8811 is required, but I assume it’s doing some RS485 “translations”.
I did some more research, and I found out why it’s needed. The RS485 terminals on the M1XSP are 2-wire half-duplex, but the Aprilaire system uses 4-wire full-duplex communication.
A number of people on other forums say that any generic RS485/RS422 to RS232 converter will work, not just the Aprilaire 8811. I ordered a cheap generic one, and I’m going to test it out.