SIM900D Hardware Design
SIM900D_HD_V1.02
09.04.2010
12
Road safety comes first! Do not use a hand-held cellular terminal or mobile when driving a
vehicle, unless it is securely mounted in a holder for hands free operation. Before making a call
with a hand-held terminal or mobile, park the vehicle.
GSM cellular terminals or mobiles operate over radio frequency signals and cellular networks
and cannot be guaranteed to connect in all conditions, for example no mobile fee or a invalid
SIM card. While you are in this condition and need emergent help, Please Remember using
emergency calls. In order to make or receive calls, the cellular terminal or mobile must be
switched on and in a service area with adequate cellular signal strength.
Some networks do not allow for emergency call if certain network services or phone features
are in use (e.g. lock functions, fixed dialing etc.). You may have to deactivate those features
before you can make an emergency call.
Also, some networks require that a valid SIM card be properly inserted in the cellular terminal
