M12 Hardware Design
M12_Hardware_Design_V3.3 - 24 -
Table 6: Overview of operating modes
The module will automatically go into SLEEP mode if DTR
is set to high level and there is no interrupt (such as GPIO
interrupt or data on serial port).
In this case, the current consumption of module will reduce
to the minimal level.
During SLEEP mode, the module can still receive paging
message and SMS from the system normally.
Software is active. The module has registered to the GSM
network, and the module is ready to send and receive data.
GSM connection is ongoing. In this mode, the power
consumption is decided by the configuration of Power
Control Level (PCL), dynamic DTX control and the working
RF band.
The module is not registered to GPRS network. The module
is not reachable through GPRS channel.
The module is registered to GPRS network, but no GPRS
PDP context is active. The SGSN knows the Routing Area
where the module is located at.
The PDP context is active, but no data transfer is ongoing.
The module is ready to receive or send GPRS data. The
SGSN knows the cell where the module is located at.
There is GPRS data in transfer. In this mode, power
consumption is decided by the PCL, working RF band and
GPRS multi-slot configuration.
Normal shutdown by sending the “AT+QPOWD=1” command, using the
PWRKEY or the EMERG_OFF pin. The power management ASIC
disconnects the power supply from the base band part of the module, and only
the power supply for the RTC is remained. Software is not active. The serial
interfaces are not accessible. Operating voltage (connected to VBAT) remains
applied.
Minimum
functionality
mode (without
removing power
supply)
“AT+CFUN” command can set the module to a minimum functionality
mode without removing the power supply. In this case, the RF part of the
module will not work or the SIM card will not be accessible, or both RF part
and SIM card will be closed, but the serial port is still accessible. The power
consumption in this case is very low.
1) Use the EMERG_OFF pin only while failing to turn off the module by the command
“AT+QPOWD=1” and the ON/OFF pin. Please refer to Section 3.4.2.4.