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SIM548C Hardware Design
be automatic shutdown soon.
If the voltage
≤
3.4V, the following URC will be presented:
UNDER-VOLTAGE POWER DOWN
If the voltage
≥
4.6V, the following URC will be presented:
OVER-VOLTAGE POWER DOWN
After this moment, no further more AT commands can be executed. The module logs off from
network and enters POWER DOWN mode, and only the RTC is still active. POWER DOWN can
also be indicated by STATUS pin, which is a low level voltage in this mode.
3.4.2.4 Over-temperature or under-temperature automatic shutdown
The GSM part will constantly monitor the temperature of the module, if the temperature is equal
or higher than 85
℃
, the following URC will be presented:
+CMTE: 1
If the temperature
≤
-40
℃
, the following URC will be presented:
+CMTE:-1
The uncritical temperature range is -45
℃
to 90
℃
. If the temperature
≥
90
℃
or
≤
-45
℃
, the
module will be automatic shutdown soon.
If the temperature
≥
90
℃
, the following URC will be presented:
+CMTE:2
If the temperature
≤
-45
℃
, the following URC will be presented:
+CMTE:-2
After this moment, the AT commands can’t be executed. The module logs off from network and
enters POWER DOWN mode, and only the RTC is still active. POWER DOWN can also be
indicated by STATUS pin, which is a low level voltage in this mode.
To monitor the temperature, you can use the “AT+CMTE” command to read the temperature when
the module is power on.
SIM548C_HD_V1.01
09.05.2008
31