5.11 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.

5.11.1UART1

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.

LZT 123 1836

53