Integration Manual

SARA-R4 series - System integration manual
UBX-16029218 - R20 System description Page 21 of 129
C1-Public
The initial operating mode of SARA-R4 series modules is the one with VCC supply not present or below
the operating range: the modules are switched off in not-powered mode.
Once a valid VCC supply is applied to the SARA-R4 series modules, they remain switched off in the
power-off mode. Then the proper toggling of the PWR_ON / PWR_CTRL input line is necessary to
trigger the switch-on routine of the modules that subsequently enter the active mode.
SARA-R4 series modules are fully ready to operate when in active mode: the available communication
interfaces are completely functional and the module can accept and respond to AT commands,
entering connected mode upon cellular RF signal reception / transmission.
The internal GNSS functionality can be concurrently enabled on the SARA-R422M8S modules by the
dedicated +UGPS AT command, as well as the external GNSS functionality can be concurrently
enabled using SARA-R410M, SARA-R412M or SARA-R422S modules by the same AT command.
SARA-R4 series modules switch from active mode to the low power idle mode whenever possible, if
the low power configuration is enabled by the dedicated +UPSV AT command. The low power idle
mode can last for different time periods according to the specific +UPSV AT command setting,
according to the DRX / eDRX setting, and according to the concurrent activities executed by the
module, as in particular according to the concurrent GNSS activities.
SARA-R4 series modules enter the User Equipment Power Saving Mode defined in 3GPP Rel.13
whenever possible, if the use of the PSM is enabled by the +CPSMS / +UCPSMS AT commands, and
according to the +UMNOPROF AT command settings. The PSM can last for different time periods
according to the T3412 periodic TAU timer set by the network. Then, the modules enter the ultra-low
power deep-sleep mode whenever possible, if no other concurrent activities are executed by the
module, in particular if no concurrent GNSS activities are executed by the SARA-R422M8S modules.
SARA-R422, SARA-R422S and SARA-R422M8S modules may automatically enter the ultra low power
deep sleep mode in-between eDRX cycles, whenever possible, if the functionality is enabled using the
+UPSMVER AT command.
Once the modules enter the ultra-low power deep-sleep mode, the available communication interfaces
are not functional: a wake-up event, consisting in proper toggling of the PWR_ON / PWR_CTRL input
input line or the expiration of the timer set by the network, is necessary to trigger the wake-up routine
of the modules that subsequently enter back into the active mode.
SARA-R4 series modules can be gracefully switched off by the dedicated +CPWROFF AT command,
or by proper toggling of the PWR_ON / PWR_CTRL input.
Figure 5 describes the transition between the different operating modes.
Remove VCC
Switch ON:
• PWR_ON
• PWR_CTRL
Not powered
Power off
Switch OFF:
• AT+CPWROFF
• PWR_ON
• PWR_CTRL
Apply VCC
If PSM mode is enabled (AT+CPSMS=1),
if AT Inactivity Timer and Active Timer are expired,
if no other concurrent activity is executed
• Upon expiration of the Periodic Update Timer
• Using PWR_ON pin
Incoming/outgoing data, or
other dedicated network communication
No RF Tx/Rx in progress,
Communication dropped
ActiveConnected Deep Sleep
If low power idle mode is enabled (AT+UPSV≠0),
if AT Inactivity Timer is expired,
if there is none concurrent activity
Idle
Data received over UART (if AT+UPSV=4),
DTR assert to ON (if AT+UPSV=3),
Other concurrent activity
Figure 5: SARA-R4 series modules operating modes transitions