The Cellular IoT M2M RTU S475/S475E is an industrial class, high reliability, high stability, and programmable Remote Terminal Unit (RTU).
The RTU features 8 digital inputs, 6CH 24 bit analog or PT100 Resistance Temperature Detector (RTD) inputs, 4 relay outputs, 1 temperature and humidity input, 1 Ethernet RJ45 port, and 2 RS485 serial port supports 320 IO tags via Modbus RTU protocol.  
The 4G RTU can be used as Modbus RTU Master and Slave at the same time and supports transparent data transmission. The Cellular IoT RTU can be used as Modbus RTU Master to reading smart meters, I/O modules, PLC, and converts to SMS alert once triggered the threshold value, or transmit data to remote server over GPRS/3G/4G network. 
The RTU supports BLIIoT IoT RTU protocol, Modbus RTU, Modbus TCP, MQTT protocol, which can communicate directly with the server, cloud platform or SCADA.