Integration Manual

LISA-U2 series - System Integration Manual
UBX-13001118 - R25 System description Page 61 of 182
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 27), if the feature is enabled by the appropriate AT command (see the u-blox AT
Commands Manual [2], AT+CNMI command).
Figure 27: 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 ON for more than 1 second.
If an incoming call is answered within less than 1 second (with ATA or if auto-answering is set to
ATS0=1), then the RI line will be set to OFF earlier.
As a result:
☞ RI line monitoring cannot be used by the DTE to determine the number of received SMSs.
☞ In case of multiple events (incoming call plus SMS received), the RI line cannot be used to
discriminate the two events, but the DTE must rely on the subsequent URCs and interrogate the
DCE with the appropriate commands.
The RI line can additionally notify all the URCs and all the incoming data (PPP, Direct Link, sockets,
FTP) on all LISA-U2 series modules except for the “01” product version, if the feature is enabled by the
proper AT command (see the u-blox AT Commands Manual [2], AT+URING command): the RI line is
asserted when one of the configured events occur and it remains asserted for 1 second unless another
configured event will happen, with the same behavior described in Figure 27.
1.9.2.3 UART and power-saving
The power saving configuration is controlled by the AT+UPSV command (for the complete description
see the u-blox AT Commands Manual [2]). When power saving is enabled, the module automatically
enters low-power idle mode whenever possible; otherwise the active mode is maintained by the
module (see section 1.4 for the definition and description of module operating modes).
The AT+UPSV command configures both the module power saving and also the UART behavior in
relation to the power saving. The conditions for the module entering idle mode also depend on the
UART power saving configuration.
The AT+UPSV command can set these different power saving configurations:
 AT+UPSV=0, power saving disabled: module forced to active mode and UART interface enabled
(default)
 AT+UPSV=1, power saving enabled: module cyclic active / idle mode and UART enabled / disabled
 AT+UPSV=2, power saving enabled and controlled by the UART RTS input line
 AT+UPSV=3, power saving enabled and controlled by the UART DTR input line
SMS arrives
time [s]
0
RI ON
RI OFF
1s
SMS
time [s]
0
RI ON
RI OFF
1s