u-blox SARA-G3 Series User Manual

SARA-G3 series - System Integration Manual
UBX-13000995 - R06 Objective Specification System description
Page 63 of 218
over the used physical link (UART or SPI): the user can concurrently use AT command interface on one
MUX channel and Packet-Switched / Circuit-Switched Data communication on another multiplexer channel.
Each session consists of a stream of bytes transferring various kinds of data such as SMS, CBS, PSD,
GNSS, AT commands in general. This permits, for example, SMS to be transferred to the DTE when a
data connection is in progress.
The following virtual channels are defined for SARA-G350 modules:
 Channel 0: control channel
 Channel 1 – 5: AT commands / data connection
 Channel 6: GNSS tunneling
The following virtual channels are defined for SARA-G300 and SARA-G310 modules:
 Channel 0: control channel
 Channel 1 – 2: AT commands / data connection
For more details, refer to Mux implementation Application Note [20].
1.9.2 Auxiliary asynchronous serial interface (UART AUX)
The auxiliary UART interface is a 3-wire unbalanced 1.8 V asynchronous serial interface (only the
RXD_AUX data output and TXD_AUX data input are provided), available for SARA-G3 modules FW
upgrade by means of the u-blox EasyFlash tool and for Trace log capture (debug purpose). The AT
commands interface is not available on the auxiliary UART interface.
1.9.3 DDC (I
2
C) interface
SARA-G300 and SARA-G310 modules do not support DDC (I
2
C) interface.
An I
2
C bus compatible Display Data Channel (DDC) interface for communication with u-blox GNSS
receivers is available on SDA and SCL pins of SARA-G350 modules. Only this interface provides the
communication between the u-blox wireless module and u-blox positioning chips and modules. The AT
commands interface is not available on the DDC (I
2
C) interface.
DDC (I
2
C) slave-mode operation is not supported: the SARA-G350 wireless module can act as master
only, and the connected u-blox GNSS receiver automatically acts as slave in the DDC (I
2
C)
communication.
Two lines, serial data (SDA) and serial clock (SCL), carry information on the bus. SCL is used to
synchronize data transfers, and SDA is the data line. To be compliant to the I
2
C bus specifications, the
module bus interface pads are open drain output and pull up resistors must be used conforming to the
I
2
C bus specifications [13].
u-blox has implemented special features in SARA-G350 wireless modules to ease the design effort
required for the integration of a u-blox wireless module with a u blox GNSS receiver.
Combining a u-blox wireless module with a u-blox GNSS receiver allows designers to have full access to
the positioning receiver directly via the wireless module: it relays control messages to the GNSS receiver

u-blox SARA-G3 Series Specifications

General

Brand	u-blox
Model	SARA-G3 Series
Category	GSM/GPRS Modules
Language	English