... MODEM transmit widely, stably and reliably, KB3030 GPRS DTU is widely used in unattended operation device, Remote AMR, remote data acquisition, ... COM port through GPRS mobile data network.KB3030 GPRS DTU is used in electric power automatic system, industry monitoring, traffic management, ... mode, user can set to type A (with protocol) or type B (transparent). When set to Modem, compatible standard ...