M12 Hardware Design
M12_Hardware_Design_V3.3
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3.4.2.1. Power down module using PWRKEY pin
In application, the module can be turned off by driving the PWRKEY to a low level voltage for
certain time. The power-down scenario is illustrated in Figure 9.
The power-down procedure causes the module to log off the network and allows the software to
save important data before completely disconnecting the power supply, thus it is a safe way.
Before the completion of the power-down procedure, the module sends out the result code as
shown below:
NORMAL POWER DOWN
Note: This result code does not appear when autobauding is active and DTE and DCE are not
correctly synchronized after start-up. The module is recommended to set a fixed baud rate.
After this moment, no other AT commands can be executed. And then the module enters the
POWER DOWN mode, only the RTC is still active. The POWER DOWN mode can also be
indicated by the STATUS pin, which is a low level voltage in this mode.
VBAT
PWRKEY
(INPUT)
STATUS
(OUTPUT)
EMERG_OFF
(INPUT)
Logout net about 2s to 12s
0.6s<Pulldown<1s
>160us
Figure 9: Timing of turning off the module
3.4.2.2. Power down module using AT command
Customer’s application can use an AT command “AT+QPOWD=1” to turn off the module. This
command will let the module to log off from the network and allow the software to save important
data before completely disconnecting the power supply, thus it is a safe way.
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