RTU-531PM is an intelligent Active 3G Remote Terminal Unit with GPS. Within the high performance 32 bit CPU, RTU-531PM is suit for the hard industrial environment. It features 3G module, 4 digital inputs, 2 digital outputs, 4 analog input, 2 thermistor inputs, 1 RS-232 and SD interface. It can be used in M2M application fields to transfer the local I/O, GPS data via WCDMA/GPRS by the defined period or DI/AI triggers. The local I/O and GPS data can also be stored in the SD card to become a remote data logger. The simple I/O linkage function of RTU-531PM can reach the real time control in the local field. Therefore, RTU-531PM is an ideal solution for environmental monitoring, remote device management and vehicle monitoring system for M2M applications. Meanwhile, it is supplied with easy-to-use API and OPC server Software that streamline application development process, freeing system integrators from dealing with complex communication protocols of WCDMA/GPRS and the Internet.