The King Pigeon S2XX Serial GSM GPRS Remote Controller is a universal GSM dialer and controller as well as a GSM GPRS Remote Control and Alarm Unit. it provides multi digital relay outputs(120VAC/3A, 24VDC 3A,), upto 6 digital inputs(Opto-isolated,Active Contact, 3~24VDC, Completely isolated).can be used as pulse counter inputs), 2 temperature inputs for DS18B20, multi analog input(both of 0-20mA and 0-5V, 12 bit resolution), RS485 Port(Support Modbus RTU Protocol, more protocols can be added according to application requirements), reserved RS232 Serial Port and USB port for setting and download upgraded firmware by user on-site. It allows you to monitor and control an alarm or remote stations or equipments or machines by SMS(Short Message Service) Or GPRS. Another, it can transmit data from apparatus (thermometer, humidity meter, electric meter, flowmeter, PLC) to user or monitoring center by GPRS