DSB75 Development Support Board Rev. B1 Hardware Description
Confidential / Released
DSB75_hd_v12
Page 80 of 96
2008-08-26
7.2
Turn off the GSM Module
Normal Power-off
The best and safest approach to switch off the module is using the AT command AT^SMSO.
This procedure lets the GSM module log off from the network and safe data before it shuts
down.
Emergency-off
The emergency-off (9V power shut off or battery power off) option is reserved only for use in
the case of emergency. It should be used only exceptionally when, due to serious problems,
the software is not responding for more than 5 seconds.
After normal power-off or emergency-off, the module can be restarted by pressing the
ignition key S421.
If the power supply is restarted within one minute, the module may start automatically.
7.3 Emergency
Restart
The emergency restart option is reserved only for use in the case of emergency. It should be
used only exceptionally when, due to serious problems, the software is not responding for
more than 5 seconds.
Pulling down the module’s EMERG_RST pin by pressing the key S420 causes at release a
reset of the GSM module (0 -> 1 edge).
This may cause the loss of information stored in the volatile memory since the reset is
initialized.
The 2-pin jumper X421 connected in parallel to the key S420 can be used to shut off the
module from a remote unit.