... RS232 modem, GSM IP modem, GPRS data modem, data terminal,GPRS DTU, TCP/IP modem, Support transparent data transfe, ... High-performanceSupport TCP server and support multi TCP client connection(optional)Support double data centers, one main and another ... /1.8V user card interface, 15KV ESD protectionPowerTerminal block interface, reverse-voltage and overvoltage protectionTerminal BlockAntenna Interface ...