The GSM Controller RTU5011 is a universal GSM dialer and controller as well as a GSM Remote Control and Alarm Unit. it provides 8 relay drivable outputs(12V-24V), 8 inputs,4AD Inputs and RS232 Serial Port. It allows you to monitor and control an alarm or remote stations or equipments or machines by SMS(Short Message Service) Or transport data between user and PLC. Another, it can transmit data from apparatus (thermometer, humidity meter, electric meter, flowmeter) to user or monitoring center by SMS(GSM DTU).