User's Manual

Cinterion
®
ELS61-AUS Hardware Interface Description
2.1 Application Interface
52
 ELS61-AUS_HID_v00.031 2016-06-03
Confidential / Preliminary
Page 40 of 102
2.1.13.4 Fast Shutdown
The GPIO4 interface line can be configured as fast shutdown signal line FST_SHDN. The con-
figured FST_SHDN line is an active low control signal and must be applied for at least 10 mil-
liseconds. If unused this line can be left open because of a configured internal pull-up resistor.
Before setting the FST_SHDN line to low, the ON signal should be set to low (see Figure 19).
Otherwise there might be back powering at the ON line in Power Down mode.
By default, the fast shutdown feature is disabled. It has to be enabled using the AT command
AT^SCFG "MEShutdown/Fso". For details see [1].
If enabled, a low impulse >10 milliseconds on the FST_SHDN line starts the fast shutdown. The
fast shutdown procedure still finishes any data activities on the module's flash file system, thus
ensuring data integrity, but will no longer deregister gracefully from the network, thus saving
the time required for network deregistration.
Figure 19: Fast shutdown timing
Please note that if enabled, the normal software controlled shutdown using AT^SMSO will also
be a fast shutdown, i.e., without network deregistration. However, in this case no URCs includ-
ing shutdown URCs will be provided by the AT^SMSO command.
BATT+
VCORE
V180
VDDLP
Fast shut down procedure Power down
EMERG_RST
ON
GPIO4/FST_SHDN