User's Manual

LZT 123 1836 57
5.12 Serial Data Interfaces
The serial channels consist of two UARTs and a USB port. These provide
communication links to the application or accessory units.
The serial channels can be used in differing configurations, depending upon the users
requirements and application. In practice, both UARTs can be configured as either
the control interface or the logging interface. Similarly, control and logging can be
carried out simultaneously on the USB interface. However, the common (default)
configuration options are described:
UART1 has full RS-232 functionality and is used for all on- and off –line
communication (modem sleep & wake functional control is an integral component of
this interface). Its intended use is that of the primary command (AT) interface.
UART2 behaves as a general-purpose serial data link. It can be used for data logging
and de-bugging purposes. It can also be used as a data interface to peripheral
devices, such as a GPS receiver.
The USB port provides a convenient general purpose peripheral (slave) port for use
with host devices which have USB controllers.
5.12.1 UART1
Pin Name Direction Function
53 RI Output Ring Indicator
54 DCD1 Output Data Carrier Detect (UART1)
55 DTR1 Input Data Terminal Ready (UART1)
57 RTS1 Input Ready To Send (UART1)
58 CTS1 Output Clear To Send (UART1)
59 DTM1 Input Data To Module from host (UART1)
60 DFM1 Output Data From Module to host (UART1)
56 DSR1 Output Data Set Ready (UART1)
UART1 is a full featured Universal Asynchronous Receiver Transmitter providing full-
duplex asynchronous communication.