Confidential
MANUAL
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7/198 17-LXE 108 566 Uen
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Note: Any hard copy of this document is for reference only.
Due to template and application dependencies the header and footer may fail to display correct data. It is the
responsibility of the user to ensure that they have a correct and valid version. Any outdated hard copy is invalid and must be removed from possible use.
3.1.2.5 HW_SD
This signal, located on pin 15 in the system connector, provides the ability of performing a hardware shutdown of
the module. It is a bi-directional signal that is pulled up inside the phone module.
Figure 19: HW_SD Recommendation
Note:
The Module must be shutdown by either toggling the shutdown pin or issuing the AT+CFUN=0 command.
The GM41 is not designed to have its power source removed without first receiving a shutdown signal.
Furthermore, the shutdown procedure initiates deregistration from the network which is required for proper
operation.
3.1.3 SIM Signals Recommended Circuitry
By default, the external SIM interface supports a 250mm cable. All signals except SIMDET shall be directly
connected to its respective signal on the SIM-holder. SIMDET shall be pulled low when an external SIM is present.
3.1.3.1 SIM-Holder
It is recommended that the SIM-holder used by the application is of locking configuration, i.e. the SIM-card is locked
in position by the SIM-holder.
It is also recommended that the application ensures that the SIM-card cannot be removed from the SIM-holder
while being active, since this could result in loss of data, or in worst case damage the SIM-card. This can be done
by detecting the removal/opening of the SIM-card cover, and forwarding that information to the phone module
through the SIMDET-signal. That way the phone module can power down the SIM before the user removes the
SIM-card from the SIM-holder.
The application cannot connect the VPP-contact (C6) of their SIM-holder to anything. This pin must be left not
connected (floating).
