User's Manual

TOBY-R2 series - System Integration Manual
UBX-16010572 - R04 System description
Page 39 of 147
1.9.1.2 UART interface configuration
The UART interface of TOBY-R2 series modules is available as AT command interface with the default
configuration described in Table 10 (for more details and information about further settings, see the u-blox AT
Commands Manual [2]).
Interface
AT Settings
Comments
UART interface
AT interface: enabled
AT command interface is enabled by default on the UART physical interface
AT+IPR=0
One-shot autobauding enabled by default on the modules
AT+ICF=3,1
8N1 frame format enabled by default
AT&K3
HW flow control enabled by default
AT&S1
DSR line (Circuit 107 in ITU-T V.24) set ON in data mode
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and set OFF in command mode
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AT&D1
Upon an ON-to-OFF transition of DTR line (Circuit 108/2 in ITU-T V.24), the module (DCE)
enters online command mode
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and issues an OK result code
AT&C1
DCD line (Circuit 109 in ITU-T V.24) changes in accordance with the Carrier detect status; ON
if the Carrier is detected, OFF otherwise
MUX protocol: disabled
Multiplexing mode is disabled by default and it can be enabled by AT+CMUX command. For
more details, see the Mux Implementation Application Note [11].
The following virtual channels are defined:
 Channel 0: control channel
 Channel 1 – 5: AT commands / data connection
 Channel 6: GNSS tunneling
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Table 10: Default UART interface configuration
1.9.1.3 UART signals behavior
At the module switch-on, before the UART interface initialization (as described in the power-on sequence
reported in Figure 14), each pin is first tri-stated and then is set to its relative internal reset state
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. At the end of
the boot sequence, the UART interface is initialized, the module is by default in active-mode, and the UART
interface is enabled as AT commands interface.
The configuration and the behavior of the UART signals after the boot sequence are described below. See
section 1.4 for definition and description of module operating modes referred to in this section.
RXD signal behavior
The module data output line (RXD) is set by default to the OFF state (high level) at UART initialization. The
module holds RXD in the OFF state until the module does not transmit some data.
TXD signal behavior
The module data input line (TXD) is set by default to the OFF state (high level) at UART initialization. The TXD
line is then held by the module in the OFF state if the line is not activated by the DTE: an active pull-up is enabled
inside the module on the TXD input.
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For the definition of the interface data mode, command mode and online command mode see the u-blox AT Commands Manual [2]
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Not supported by “02” product versions
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See the pin description table in the TOBY-R2 series Data Sheet [1]