chrisan
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Connecting RCS RS485 Thermostat - How To?

Sat Jan 28, 2017 4:52 pm

I cant's get the unit to respond. myServer connects to the appropriate com port and just sends status requests until the cows come in.
The appropriate thermostat network address is specified in the setup.
All of the comm parameters are correctly set in the com port driver.

So, I think my wires are crossed. RCS are a 2 wire setup. On the PCB of the thermostat you've got T+, R- and Gnd.

In my little DB9 adapter I have T+ T- R+ and R-

I thought it was supposed to be done like this:

Thermostat side T+ ==> R+ Computer side
R- ==> T-

That didn't work. So after that I think I tried every other possible combination. Now I'm just tired and hope someone can throw me a fish. :)

Thanks, Chris

chrisan
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Re: Connecting RCS RS485 Thermostat - How To?

Sat Jan 28, 2017 4:54 pm

That didn't format right:

RCS T+ to computer R+
RCS R- to computer T-

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DavidL
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Re: Connecting RCS RS485 Thermostat - How To?

Sat Jan 28, 2017 5:50 pm

Don't forget that RCS is RS485, not RS232.
You need a RS232 to RS485 adapter plugged into the PC's comport

"SERIAL COMMUNICATIONS TEST
Connect the TR16 to a PC via a RS232/485 converter to a PC serial COM port.
Note: Any RS232 to RS485 adapter used with RCS serial thermostats must have AUTOMATIC
SEND DATA CONTROL. All RCS converters have this feature, if you use another type of converter,
be sure it has this capability.
Using Windows HyperTerminal.
• Set up a direct connection session to the COM port you will be using on the PC.
• Configure Port Settings to 9600 baud, 8 bit, No parity, 1 stop bit and no flow control.
• Under Settings tab go to ASCII Setup…
• Set the ASCII sending to echo characters and no delays.
• Set ASCII receiving to Append line feeds and Wrap lines.
NOTE: RCS serial ASCII commands are CASE sensitive!
Verify Serial communications by typing the following command sequence: A=1 R=1 <cr>
Thermostat should reply with the R1 status message. A=00 O=1 T=xx SP=xx SPC=xx SPH=xx M=x FM=x
If you have problems communicating, check addresses and port settings.
You can also use the RCS Thermostat Control Program to check out serial communications to the
TR16. "

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