System Overview

System Unit Rear Panel Connectors

RS-232C Serial Input/Output Connector

You can attach a variety of pointing devices (such as a mouse or trackball), or peripheral devices (such as printers, plotters, modems, and scanners) to the RS-232C Serial Input/Output (SIO) ports on this computer. Consult the documentation that accompanies each pointing or peripheral device for specific information concerning its use.

The SIO ports are programmable. This means that you can set functions such as bit rate, character length, parity and stop bits using the System Administration Manager (SAM) or by selecting a system special device file with the functions already programmed. The SIO ports are used as an interface for serial asynchronous devices to the CPU.

Table 1-3shows the SIO connector pin listings. The serial connectors are 9-pin D-sub connectors. Signal names are those specified in the EIA RS-232 standard.

Table 1-3

Serial I/O Pins

 

 

 

 

 

 

Pin No.

Signal

Description

 

 

 

 

 

1

DCD

Data Carrier Detect

 

 

 

 

 

2

RXD

Receive Data

 

 

 

 

 

3

TXD

Transmit Data

 

 

 

 

 

4

DTR

Data Terminal Ready

 

 

 

 

 

5

GND

Ground

 

 

 

 

 

6

DSR

Data Set Ready

 

 

 

 

 

7

RTS

Request To Send

 

 

 

 

 

8

CTS

Clear To Send

 

 

 

 

 

9

RI

Ring Indicator

 

 

 

 

Chapter 1

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