SIM340 Hardware Design
For detailed information about “AT+CFUN”, please refer to
document [1]
.
3.5.2 Sleep mode (slow clock mode)
We can control SIM340 module to enter or exit the SLEEP mode in customer applications through
DTR signal.
When DTR is in high level and there is no on air and hardware interrupt (such as GPIO interrupt
or data on serial port), SIM340 will enter SLEEP mode automatically. In this mode, SIM340 can
still receive paging or SMS from network but the serial port is not accessible.
Note: For SIM340, it requests to set AT command “AT+CSCLK=1” to enable the sleep mode;
the default value is 0, that can’t make the module enter sleep mode.For more details please
refer to our AT command list.
3.5.3 Wake up SIM340 from SLEEP mode
When SIM340 is in SLEEP mode, the following methods can wake up the module.
Enable DTR pin to wake up SIM340.
If DTR Pin is pulled down to a low level, this signal will wake up SIM340 from power
saving mode. The serial port will be active after DTR changed to low level for about 40ms.
Receiving a voice or data call from network to wake up SIM340.
Receiving a SMS from network to wake up SIM340.
RTC alarm expired to wake up SIM340.
Note: DTR pin should be held low level during communicating between the module and DTE.
3.6 Summary of state transitions (except SLEEP mode)
Table
8
: Summary of state transitions
Further mode
Current mode
POWER DOWN
Normal
mode
Alarm mode
POWER DOWN
Use
PWRKEY
Switch on from POWER DOWN
mode by RTC
Normal mode
AT+CPOWD or
use PWRKEY pin
Set alarm by “AT+CALARM”, and
then switch off the module. When the
timer expire, the module turn on and
enter Alarm mode
Alarm mode
Use PWRKEY
pin or wait
Use
AT+CFUN
SIM340_HD_V3.09
18.03.2009
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