GPRS 3G LTE Cat.M1 NB IoT RTU The DinBox RTU M4 is a low-cost micro RTU with built-in wide range AC power supply. The power supply comes with a supercap back-up, in order to ensure the required energy to communicate with the SCADA system, even after a mains power supply disconnect. Direct WAN communication is possible thanks to the built-in Sierra Wireless communication module. Everything is managed by a powerful Cortex M4 microcontroller. Finally, the RTU is built into a DIN rail mountable housing. The DinBox RTU M4 uses IEC 60870-5-104 to communicate as a slave with the SCADA system (master). Other protocols can be implemented. The DinBox has 8 active digital inputs, which enable sending events when a change has been detected. Furthermore, it has 2 digital outputs which can be controlled via SCADA commands, and 2 analogue inputs to monitor. Thanks to the modbus master implementation and the modbus-to-IEC104 mapping the DinBox RTU M4 can be used as a gateway to connect other modbus slave IEDs. Authentication, integrity and security are provided per application or service running on the RTU by protecting the transport layer of the protocol stack with TLS (Transport Layer Security).