User's Manual

SARA-R4 series - System Integration Manual
UBX-16029218 - R03 System description
Page 20 of 94
1.6.3 Module reset
SARA-R4 series modules can be properly reset (rebooted) by:
 AT+CFUN command (see SARA-R4 series AT Commands Manual [2]).
In the case listed above an “internal” or “software” reset of the module is executed: the current parameter
settings are saved in the module’s non-volatile memory and a proper network detach is performed.
An abrupt hardware shutdown occurs on SARA-R4 series modules when a low level is applied on RESET_N input
pin for a valid time period. 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. Then, the module remains in power-off mode as long
as a switch on event does not occur applying a proper low level to the PWR_ON input.
It is highly recommended to avoid an abrupt hardware shutdown of the module by forcing a low level on
the RESET_N input during modules 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 provide a reply to a specific AT command
after a time period longer than the one defined in the SARA-R4 series AT Commands Manual [2].
The RESET_N input pin is equipped with an internal pull-up to the V_INT supply. Detailed electrical
characteristics with voltages and timings are described in SARA-R4 series Data Sheet [1].