... gsm modem, rs485 modem 2.with standard TCP/IP protocol stack, i/o 3.Support transparent data transfer 4. Support DDNS IP modem, RS232 modem, GSM IP modem, GPRS ... GPRS network.It adopts high-powered industrial 32 bits CPU and embedded real time operating system. ... output function. Ideal for M2M fields, smart grid, industrial automation, telemetry, finance, POS, water supply, environment protection, ...