Minimalist IoT gateway is a smart Modbus/RTU/IO to GPRS/4G/WiFi gateway. The gateway expands data communication over wireless networks with Secure and two-way communication. The minimalist gateway replaces the wired approach of sending the slave data to the centralized server, either single or multiple slaves using TCP/HTTP/UDP/CoAP/MQTT protocol. All the parameters are configurable via PC Utility or SMS or Server IP Commands. All configurations are done remotely, not required to have the device during configurations. The gateway is optionally provided with a cloud based dashboard interface to manage device machines easily. Users can monitor and control the Slave and I/O data of RTU devices.