Modbus is working, so Modbus relay modules can be controlled via RS485!
Python code of this example:
import minimalmodbus
import serial
#assign RS-485 interface to serial port (use “COM…” for Windows, “/dev/ttyUSB…” for Linux)
AOG_Modbus = minimalmodbus.Instrument(“/dev/ttyUSB1”, 1)
AOG_Modbus.serial.baudrate = 9600
Relay = 5
State = 0x0100 # possibilities: 0x0100 = on, 0x0200 = off, etc
status = AOG_Modbus.write_register(Relay, State, 0, 6, False)