Good day, guys

I want to connect my MCU to an old temperature controller whose communication interface is an RS-485 and uses Modbus as its protocol. I want to be able to control that controller remotely using the MCU. Can anyone help me or give me any tips?

Thanks,

 

There are quite a few suppliers of RS485 IC's, TI for one.
There is quite a bit of information on the Modbus sites for the protocol, including free master or slave simulator programs.
Max.

 

You mean like this one?

http://www.ti.com/lit/ds/symlink/sn65hvd10.pdf

Also, would this be connected to the UART pins of the MCU?

 

Yes, I have also used a cheap ebay RS232 to RS485 convertor where a RS232 was already in place.
Max.

 

SN75176 is a early model of the basic RS-485 transceiver. There are many newer models now available from various manufacturers.