Keywords:wireless gsm 3g rtu, data converter,Wireless SMS Alarm,RF Data Acquisition Module to SMS gateway, The Wireless GSM 3G RTU S280 is a powerful wireless RTU special for monitoring wireless distributed multi-point I/O by RF 433Mhz wireless network, the range can up to 3~5Km, it inbuilt industrial 433Mhz RF module and GSM/GPRS/3G/RJ45 module. It is special for converting the wired detectors/transducers/PLC/meters to 433 MHz wireless and then transmits it to GSM/SMS/GPRS/3G/Ethernet network. The Wireless GSM 3G RTU S280 can be widely used in lots of applications, e.g.: BTS monitoring, remote data acquisition, telemetrically, farm, energy saving, agriculture, automatically meter reading system, weather station, storage, factory and other applications. It supports 433Mhz, voice, SMS, GPRS, 3G and TCP/IP internet communications. The Wireless GSM 3G RTU S280 supports Modbus RTU, Modbus TCP, TCP/UDP, and data transparent transmission protocol; it can be used as RF Data Acquisition Module to SMS gateway, RF Data Acquisition Module to GPRS/3G/ Internet Router, Modbus RTU Master or Modbus RTU Slave. The Wireless GSM 3G RTU S280 can be used as Wireless SMS Alarm, when the wireless endpoint value exceeds the threshold, it also can send pre-definition SMS to users.