MTD2000 AT Command Guide R12
Confidential
DAVISCOMMS (S) PTE LTD
96 /105
25 Miscellaneous Functions
25.1 GSM Monitoring
The firmware will monitor the GSM module every 4 minutes to check if the GSM module
is alive. It will shorten the monitoring interval to every minute if there is no response
from the GSM module, and reset the GSM module and clear the GSM register flag in
the event table if there is no response after three consecutive attempts with one minute
interval. It will repeat the above cycle and set the GSM register flag once there is
response from the GSM module.
If dual SIM auto switching is enabled, the firmware will switch over to another SIM card
when GSM module has no response.
The firmware will monitor the GSM module every 4 minutes to check if roaming occurs.
If dual SIM auto switching is enabled, the firmware will switch over to another SIM when
roaming take places.
25.2 GPS Monitoring
The firmware will monitor the GPS module every 10 seconds to check if the GPS
module is alive. It will reset the GPS module and clear the GPS operational flag in the
event table if there is no response from the GPS module after three consecutive checks.
Thereafter, the firmware will monitor the GPS module every 2 minutes and will set the
GPS operational flag if the response is resumed.
25.3 GPS Antenna Detection
The firmware will monitor the GPS external antenna to check for disconnection. When
the GPS external antenna is disconnected from the device, the firmware will set the
GPS antenna flag in the event table. When the GPS external antenna is connected to
the device, the firmware will clear the GPS antenna flag.
25.4 Low Battery Shutdown
When the battery voltage drops below 3 V, the device will shutdown and send out an
unsolicited response to indicate device shutdown. The device will reset and resume
normal operation when the battery voltage goes above 3.6 V (e.g. apply external power
source).
