AirGate-Modbus is a wireless multifunctional gateway that allows the transparent and easy insertion of wireless branches into existing wired RS485 networks. The AirGate-Modbus has four operation modes, Modbus Master, multiplexer, USBRS485 converter and simple wireless RS485 extension. A proprietary protocol based on IEEE 802.15.4 facilitates operation in Star mode, allowing the connection of several wireless segments to an existing Modbus RS-485 network.