Integration Manual

TOBY-L2 and MPCI-L2 series - System Integration Manual
UBX-13004618 - R04 Advance Information System description
Page 42 of 141
1.9.2 Asynchronous serial interface (UART)
The UART interface is not available on MPCI-L2 series modules.
The UART interface is not supported by the TOBY-L2x0-00S product version.
1.9.2.1 UART features
The UART interface is a 9-wire 1.8 V unbalanced asynchronous serial interface (UART) that can be connected to
an application host processor for AT commands and data communication.
The module firmware can be upgraded over the UART interface by means of the Firmware upgrade over AT
(FOAT) feature only: for more details see section 1.15 and Firmware update application note [4].
UART interface provides RS-232 functionality conforming to the ITU-T V.24 Recommendation (more details
available in ITU Recommendation [7]), with CMOS compatible signal levels: 0 V for low data bit or ON state, and
1.8 V for high data bit or OFF state. For detailed electrical characteristics see TOBY-L2 Data Sheet [1].
TOBY-L2 modules are designed to operate as LTE/3G/2G cellular modems, i.e. the data circuit-terminating
equipment (DCE) is according to the ITU-T V.24 Recommendation [7]. A customer application processor
connected to the module through the UART interface represents the data terminal equipment (DTE).
The signal names of the UART interface of the TOBY-L2 series modules conform to the ITU-T V.24
Recommendation [7]: e.g. TXD line represents the data transmitted by the DTE (application processor data
output) and received by the DCE (module data input).
The UART interface is controlled and operated with:
 AT commands according to 3GPP TS 27.007 [8], 3GPP TS 27.005 [9], 3GPP TS 27.010 [10]
 u-blox AT commands
For the complete list of supported AT commands and their syntax see u-blox AT Commands Manual [3].
1.9.2.2 UART interface configuration
The UART interface of TOBY-L2 series modules is configured as described in Table 11 (for information about
further settings, see the u-blox AT Commands Manual [3]).
Interface
AT Settings
Comments
UART interface
AT interface: enabled
AT command interface is enabled by default on the UART physical interface
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
 Channel 7: SIM Access Profile
Table 11: Default UART interface configuration