Reproduction forbidden without Fibocom Wireless Inc. written authorization - All Rights Reserved
FIBOCOM FG621-LA Series Hardware Guide
Page 28 of 57
Shutdown
Mode
Shutdown Method
Applicable Scenario
Hardware
shutdown
Pull down PWRKEY for at least 2.1s,
3s~8s recommended
Hardware normal shutdown
AT
command
shutdown
AT+
CPWROFF
Software normal shutdown
Note:
1. When the module is working properly, do not cut off the power of the module immediately to
avoid damaging internal flash. It is strongly recommended to shut down the module by
PWRKEY pin or AT command before cutting off the power supply.
2. When using the AT command to shut down the module, make sure that the PWRKEY pin is
always at the high level after the shutdown command is executed, otherwise the module will
automatically power on again.
3. During the shutdown process, it takes about 6 seconds from the release of PWRKEY to the
complete power-off of VDD_EXT. Other operations such as power-on, reset, etc. can be
performed only after the complete power-off.
The shutdown timing is shown as follows:
Figure 5-4 Shutdown timing
5.1.2 Reset
FG621-LA series module can be reset by hardware and software.
Table 5-3 Reset modes
Reset Mode
Reset Method
Hardware reset
Pull down RESET_N pin for more than 2s, then release it, 3s~8s
recommended
Software reset
Send AT command AT+CFUN=15
Clients can control RESET_N pin by OC/OD drive circuits and button switch. The reference circuits are
