SIM340 Hardware Design
following figure.
Figure 11: Timing of restart system
3.5 Power saving
There are two methods for the module to enter into low current consumption status. “AT+CFUN”
is used to set module into minimum functionality mode and DTR hardware interface signal can be
used to lead system to be in SLEEP mode (or slow clocking mode).
3.5.1 Minimum functionality mode
Minimum functionality mode reduces the functionality of the module to a minimum and, thus,
minimizes the current consumption to the lowest level. This mode is set with the “AT+CFUN”
command which provides the choice of the functionality levels <fun>=0
，
1
，
4
0: minimum functionality;
1: full functionality (default);
4: disable phone both transmit and receive RF circuits;
If SIM340 has been set to minimum functionality by “AT+CFUN=0”, the RF function and SIM
card function will be closed, in this case, the serial port is still accessible, but all AT commands
correlative with RF function or SIM card function will not be accessible.
If SIM340 has been set by “AT+CFUN=4”, the RF function will be closed, the serial port is still
active in this case, all AT commands correlative with RF function will not be accessible.
After SIM340 has been set by “AT+CFUN=0” or “AT+CFUN=4”, it can return to full
functionality by “AT+CFUN=1”.
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