Integration Manual

Table Of Contents
TOBY-L3 series - System Integration Manual
TSD-19090601 - R13 System Integration Manual Page 36 of 143
Figure 14 describes the TOBY-L3 series modules’ proper normal switch-off sequence started by means of
the +CPWROFF AT command, allowing storage of current parameter settings in module’s non-volatile
memory and a clean network detach, with the following phases
The +CPWROFF AT command is sent to the module by the external application: the module starts the
switch-off routine
Then, the module replies OK on the AT interface: the switch-off routine is in progress
At the end of the switch-off routine, all the digital pins are tri-stated and all the internal voltage
regulators are turned off, including the generic digital interfaces supply (V_INT).
Then, the module remains in power-off mode as long as a switch-on event does not occur (i.e. applying
a suitable low level pulse to the PWR_ON input pin), and enters not-powered mode if the supply is
removed from the VCC pins.
Figure 14: Description of TOBY-L3 series power-off sequence, as triggered by +CPWROFF AT command
The Internal Reset signal is not available on a module pin, but it is highly recommended to monitor the
V_INT pin to sense the end of the switch-off sequence.
VCC supply can be removed only after V_INT goes low: an abrupt removal of the VCC supply during
TOBY-L3 series modules normal operations may lead to an unrecoverable faulty state!
The duration of each phase in the TOBY-L3 series modules’ switch-off routines can largely vary
depending on the application / network settings and the concurrent module activities.