SRT-50/80/90 series thermostat belongs to the electronic thermostat by using electronic controller for cooling and heating. Three basic types in this series are all get LCD screen, back-light display, four modes of wind-speed setting, 4 pipes for cooling or heating. It can be connected to the BA system directly, supporting BACnet MS/TP, Modbus, and M-Bus communication, billing, remote parameter setting, data reading and tele-control. They are widely used for control room temperature in heating, cooling or year-round central air-conditioning system, especially in the control system such as fan coil, electrical heater.