LISA-U series - System Integration Manual
UBX-13001118 - R17
Advance information
System description
Page 43 of 190
1.6.2
Module power-off
The power-off sequence of LISA-U series modules can be correctly started, so that the current parameter settings
are saved in the module’s non-volatile memory and a proper network detach is performed, in one of these ways:
AT+CPWROFF command (more details in
u-blox AT Commands Manual
Low pulse on the
PWR_ON
pin for at least 1 s (not supported by LISA-U1 series and LISA-U200-00S version)
An over-temperature or an under-temperature shutdown occurs when the temperature measured within the
cellular module reaches the dangerous area, if the optional Smart Temperature Supervisor feature is enabled and
configured by the dedicated AT command. For more details see the section 3.14 and to the
u-blox AT
Commands Manual
[3], +USTS AT command.
An abrupt under-voltage shutdown occurs on LISA-U modules when the
VCC
supply is removed, but in this case
the current parameter settings are not saved in the module’s non-volatile memory and a proper network detach
cannot be performed.
It is highly recommended to avoid an abrupt removal of the
VCC
supply: the power off sequence of the
module must be properly started as described above (e.g. by means of the AT+CPWROFF command), and
a proper
VCC
supply must be maintained at least until the end of the power off sequence, which occurs
when the generic digital interfaces supply output (
V_INT
) is switched off by the module.
An abrupt hardware shutdown occurs on LISA-U series modules when a low level is applied to the
RESET_N
pin.
In this case, the current parameter settings are not saved in the module’s non-volatile memory and a proper
network detach is not performed.
It is highly recommended to avoid an abrupt hardware shutdown of the module by forcing a low level on
the
RESET_N
input pin during module normal operation: the
RESET_N
line should be set low only if reset
or shutdown via AT commands fails or if the module does not reply to a specific AT command after a time
period longer than the one defined in the
u-blox AT Commands Manual
