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SARA-G450 - System integration manual
UBX-18046432 - R08
System description
Page 41 of 143
C1-Public
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The signal names of SARA-G450 modules’ auxiliary UART interface conform to the ITU-T V.24
recommendation
: e.g. the TXD_AUX line represents the data transmitted by the DTE
(application processor data line output) and received by the DCE (module data line input).
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Hardware flow control and software flow control are not supported on the auxiliary UART interface.
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SARA-G450 modules do not support automatic baud rate detection (autobauding) and automatic
frame recognition on the auxiliary UART interface: 115200 bit/s and 8N1 are the default setting.
The auxiliary UART interface provides only data output and input signals, so that for example the &C,
&D and &S AT commands have no effect on the interface, since there are no DCD, DTR and DSR lines
available.
When the auxiliary UART interface is configured in AT command mode by means of the +USIO AT
command (for more details, see
and the u-blox AT commands manual
), then both the
primary main UART and the secondary auxiliary UART can receive AT commands in parallel. The
primary main UART can be used for AT commands, data communication and multiplexer
functionalities, while the secondary auxiliary UART can be used for AT commands and data
communication.
See the “Multiple AT command interfaces” appendix in the u-blox AT commands manual
further details regarding multiple AT command interfaces general usage and related AT command
profile configurations.
The power saving configuration is controlled by the +UPSV AT command, which can be retrieved over
the secondary auxiliary UART interface as over the primary main UART interface: it sets the module
power saving configuration and also the interface behavior in relation to the power saving. For further
details regarding power saving configurations, see section
, +UPSV AT command.
The multiplexer protocol is not supported over SARA-G450 modules’ auxiliary UART interface.
SARA-G450 modules’ auxiliary UART interface can be configured in GNSS tunneling mode by means
of the +USIO AT command (for more details, see
and the u-blox AT commands manual
so that:
raw data flow to and from a u-blox GNSS receiver connected to the cellular module via I2C interface
is available (for more details, see the u-blox AT commands manual
, +UGPRF AT command)
None flow control is supported
Baud rate is 115200 bit/s
Frame format is 8N1 (8 data bits, no parity, 1 stop bit)