Integration Manual

Table Of Contents
TOBY-L2 and MPCI-L2 series - System Integration Manual
UBX-13004618 - R26 System description
Page 45 of 162
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 TOBY-L2 series modules 00 product versions.
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 [6].
UART interface provides RS-232 functionality conforming to the ITU-T V.24 Recommendation [8], 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]), providing:
data lines (RXD as output, TXD as input),
hardware flow control lines (CTS as output, RTS as input),
modem status and control lines (DTR as input, DSR as output, DCD as output, RI as output).
TOBY-L2 modules are designed to operate as LTE/3G/2G cellular modems, i.e. as the data circuit-terminating
equipment (DCE) according to the ITU-T V.24 Recommendation [8]. A host application processor connected to the
module through the UART interface represents the data terminal equipment (DTE).
UART signal names of TOBY-L2 modules conform to the ITU-T V.24 Recommendation [8]: e.g. TXD line
represents data transmitted by the DTE (host processor output) and received by the DCE (module input).
The UART interface is controlled and operated with:
AT commands according to 3GPP TS 27.007 [9], 3GPP TS 27.005 [10], 3GPP TS 27.010 [11]
u-blox AT commands
For the complete list of supported AT commands and their syntax see u-blox AT Commands Manual [3],
and in particular for the UART configuration see the +IPR, +ICF, +IFC, &K, \Q, +UPSV AT commands.
Flow control handshakes are supported by the UART interface and can be set by appropriate AT commands (see
u-blox AT Commands Manual [3], &K, +IFC, \Q AT commands): hardware flow control (over the RTS / CTS lines),
software flow control (XON/XOFF), or none flow control.
Hardware flow control is enabled by default.
Software flow control is not supported by “00”, “01”, “60” and TOBY-L201-02S product versions.
The one-shot autobauding is supported: the automatic baud rate detection is performed only once, at module
start up. After the detection, the module works at the detected baud rate and the baud rate can only be changed
by AT command (see u-blox AT Commands Manual [3], +IPR).
One-shot automatic baud rate recognition (autobauding) is enabled by default.