RCS TS65I RS485 thermostat communication


New Member
Picked up a new ts65i thermostat on Ebay. The wall unit and control module work fine. Connected a PC via a RS485 converter. With the TS65I set to autosend, I get lots of good data. Following the procedure in the install manual and the command format in the RCS serial protocol document, i attempted to send commands via RS485. Got no response back on RS485 to a R1 status command. Could not command mode or setpoint changes. Basically could not get any response to RS485 commands. Checked the RS485 lines with a scope and data is being sent to the TS65I. The RCS website says they don't do support.
Can anybody help?
It's been many years since I played with RS-485 and RCS thermostats, but I vaguely recall some kind of quirk about carriage returns.  Sorry, I don't remember any more than that.
Thanks for the info. I feel I have been doing everything correct. I have not been able to find detailed info on RCS model TS65I. I have info on a TR65. The one I bought is a mystery. RCS is not willing to help on any thermostat current or discontinued.
On a positive note I found a GE thermostat which is a rebranded RCS TR40 which is very close in functionality to the TS65I. I have had NO trouble communicating with it. I got it at a great price so it softened the loss on the TS65I.
What I am still in need of is an RCS TS15 four wire remote temperature sensor. I ordered one from SmartHome-Products and have not gotten it. They have not shipped it and are not responding to emails or phone calls. I think they are out of business. Does anyone know where I can get this sensor?
Just an update on the RCS TS65I RS485 thermostat. Any ASCII command string you send it has to be terminated with a CRC16-CCITT checksum. Not a simple task. I'm still finding out how to calculate it using Arduino C++.