UMTS/HSPA Module Series
UG96 Hardware Design
UG96_Hardware_Design 31 / 76
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Automatic shutdown: Turn off the module automatically if under-voltage or over-voltage is detected.
3.7.2.1. Turn off Module Using AT Command
There are several different ways to turn off the module. It is recommended to turn off the module by
command
AT+QPOWD
. It is a safe way to turn off the module. This command will let the module log off
from the network and allow the firmware to save important data before completely disconnecting the
power supply.
The power down scenario is illustrated as the following figure.
VBAT
AT+QPOWD
Log out from network in 2s~12s
RUNNING
Power-down procedure
OFF
Module
Status
STATUS
RXD
Figure 12: Timing of Turning off through AT Command
During power down procedure, module will log off from network and save important data. After logging off,
module sends out
“OK”, then sends out “POWERED DOWN” and shuts down the internal power supply.
The power on VBAT pins is not allowed to be turned
off before the URC “POWERED DOWN” is outputted
to avoid data loss. If logging off is not done within 40s, module will shut down internal power supply
forcibly.
After that moment, module enters into the power down mode, and no other AT commands can be
executed except that only the RTC is still active. Please refer to
document [1]
for details about the
command
AT+QPOWD
.
3.7.2.2. Emergency Shutdown
The module can be shut down by the pin PWRDWN_N. It should only be used under emergency
situation.
The following table shows the pin definition of PWRDWN_N.
