... . Support DDNS IP modem, RS232 modem, GSM IP modem, GPRS data modem, data terminal,GPRS DTU, TCP/IP modem, Support transparent data transfe, gprs ip modem, gsm modemgprs modem with rs232 rs485 ... pulse wave output function. Ideal for M2M fields, smart grid, industrial automation, telemetry, finance, POS, water supply, environment protection, post, weather ...