CoolGate-M is a versatile gateway device connecting VRV/VRF air conditioning systems (Daikin, Sanyo, Toshiba, Fujitsu, LG, Mitsubishi Electric, Hitachi & Mitsubishi Heavy) to BMS or any other industrial controllers. Using MODBUS RTU protocol CoolGate-M enables full control and monitoring of the indoor units and provides access to VRV system parameters (CoolGate-M Pro). In other words CoolGate-M hides complexity of internal air conditioning communication line (including very unique physical layer) and instead provides standard MODBUS RTU interface over RS485 communication network.