User's Manual

LISA-U1/LISA-H1 series - System Integration Manual
3G.G2-HW-10002-2 Advance Information System description
Page 47 of 116
Figure 22: RI behavior during an incoming call
The RI line can notify an SMS arrival. When the SMS arrives, the RI line switches from OFF to ON for 1 s (see
Figure 23), if the feature is enabled by the proper AT command (please refer to u-blox AT Commands Manual
[2], AT+CNMI command).
Figure 23: RI behavior at SMS arrival
This behavior allows the DTE to stay in power saving mode until the DCE related event requests service.
In case of SMS arrival, if several events occur coincidently or in quick succession each event triggers the RI line
independently, although the line will not be deactivated between each event. As a result, the RI line may stay to
ON for more than 1 second.
If an incoming call is answered within less than 1 second (with ATA or if autoanswering is set to ATS0=1) than
the RI line will be set to OFF earlier.
As a result:
RI line monitoring can’t be used by the DTE to determine the number of received SMSes.
In case of multiple events (incoming call plus SMS received), the RI line can’t be used to discriminate the
two events, but the DTE must rely on the subsequent URCs and interrogate the DCE with the proper
commands.
1.9.2.3 UART and power-saving
The power saving configuration is controlled by the AT+UPSV command (for the complete description please
refer to u-blox AT Commands Manual [2], AT+UPSV command). When power saving is enabled, the module
automatically enters idle-mode whenever possible, otherwise the active-mode is maintained by the module. The
AT+UPSV command sets the module power saving configuration, but also configures the UART behavior in
relation to the power saving configuration. The conditions for the module entering idle-mode also depend on
the UART power saving configuration.
The different power saving configurations that can be set by the AT+UPSV command are described in the
following subchapters and are summarized in Table 19. For more details on the command description please
refer to u-blox AT commands Manual [2].
SMS arrives
time [s]
0
RI ON
RI OFF
1s
SMS
time [s]
0
RI ON
RI OFF
1s
1s
time [s]
151050
RI ON
RI OFF
Call incomes
1s
time [s]
151050
RI ON
RI OFF
Call incomes