This is a single phase SCR power regulators and temperature controllers 2 in 1 units, in a typical heating system, you would need a temperature controller and a SCR power regulators, and they are two separate devices, we go further and build this two devices in one package, this saves a lot of efforts for panel builders when it comes down to wiring, and RS-485 modbus is a standard feature, controller can be integrated to systems with HMI or PLC etc. the load can be directed wired to this thyristor power regulators, and it works with all kinds of inputs, Thermocuple, RTD, analog signal