... GPRS function, please disable the PIN code of the SIM card.Before install the SIM card, please power off the system first.After installation ... ring,please confirm the SIM card has been installed properly, the SIM card PIN code is disable,and the SIM card has enough charge, and ... in the open place, and hasconnect firmly to the socket.Technology Parameter:1)Working Voltage:9-15DC2)Standby Current:<30mA3 ...