... Standard and Band: GSM850/900/1800/1900MHz 3G modem. Designed with industrial grade, supports SMS, CSD, RS232, AT Commands, with the ... by dial-up, etc. It has been used for sending SMS, alarm system, data transmission, etc .Detailed information A. Wireless ... . Standard AT command interface B. Hardware System1.Interface RS232 serial port, rates: 110~230400bits/s Indicator lights: "Power", "ACT", "Online ...