TOBY-L4 series - System Integration Manual
UBX-16024839 - R04
System description
Page 33 of 143
1.6.2
Module power-off
TOBY-L4 series can be properly switched off by:
AT+CPWROFF command
3
(see the
u-blox AT Commands Manual
uCPU application
4
Low pulse on the
PWR_ON
pin, which is normally set high by an internal pull-up, for a valid time period (see
the
TOBY-L4 series
Data Sheet
[1]), module normal switch-off: the internal switch-off sequence of the
module starts when the external application releases the
PWR_ON
line from the low logic level, after that it
has been set low for an appropriate time period.
The methods listed above represent the appropriate normal switch-off events, triggering an appropriate normal
switch-off procedure of the module: the current parameter settings are saved in the module’s non-volatile
memory and a clean network detach is performed.
An abrupt under-voltage shutdown occurs on TOBY-L4 series modules when the
VCC
module supply is removed.
If this occurs, it is not possible to perform the storing of the current parameter settings in the module’s non-
volatile memory or to perform a clean network detach.
It is highly recommended to avoid an abrupt removal of the
VCC
supply during TOBY-L4 series modules
normal operations: the switch-off procedure must be started by an appropriate switch-off event (see
above), and then a suitable
VCC
supply must be held at least until the end of the modules’ internal
switch-off sequence, which occurs when the generic digital interfaces supply output (
V_INT
) is switched
off by the module.
An abrupt emergency shutdown procedure is triggered on TOBY-L4 series modules when a long enough low
pulse is set at the
PWR_ON
input pin (see the
TOBY-L4 series
Data Sheet
[1], module emergency switch-off). In
this case, storage of the current parameter settings in the module’s non-volatile memory and the clean network
detach are not performed.
This abrupt emergency shutdown procedure is intended only for use for emergency, e.g. if the module does not
provide a reply to a specific AT command after a time period longer than the one defined in the
u-blox AT
Commands Manual
[2], or if shutdown via a normal switch-off procedure fails.
An over-temperature shutdown occurs on TOBY-L4 series modules when the temperature measured within the
cellular module reaches a critical range.
3
Not supported by "00" product version
4
Not supported by "50" product version
