Host Interface Reference

Standard printers support three host interfaces: RS-232C, RS-422, and Centronics Parallel. User-level information about the installation, configuration, and use of these interfaces is included in the printer’s Guide to Operations.

RS-232C Host Interface

A printer is standard data terminal equipment (DTE), designed specifically for a direct connection to a standard data communication equipment (DCE) host. The standard signal definitions for DTE to DCE equipment are outlined in the table that follows.

Table 6-1. RS-232C DCE to DTE Signal Definitions

Pin

Signal

Function

Name

 

 

 

 

 

1

FG

Frame or chassis ground

 

 

 

2

TD

Transmitted data

 

 

 

3

RD

Received data

 

 

 

4

RST

Request to send

 

 

 

5

CTS

Clear to send

 

 

 

6

DSR

Data set ready

 

 

 

7

SG

Signal ground

 

 

 

8

DCD

Data carrier detect

 

 

 

9

 

Positive DC test voltage

 

 

 

10

 

Negative DC test voltage (unassigned)

 

 

 

11

(S)DCD

Secondary data carrier detect

 

 

 

12

(S)CTS

Secondary clear to send

 

 

 

13

(S)CTS

Secondary clear to send

 

 

 

14

(S)TD

Secondary transmitted data

 

 

 

15

TC

Transmitter clock

 

 

 

16

(S)RD

Secondary received data

 

 

 

17

RC

Receiver clock

 

 

 

18

RDC

Receiver debit clock

 

 

 

19

(S)RTS

Secondary receive to send

 

 

 

20

DTR

Data terminal ready

 

 

 

21

SQ

Signal quality detect

 

 

 

22

RI

Ring indicator

 

 

 

23

DRS

Data rate select

 

 

 

24

(TC)

External transmitter clock

 

 

 

25

BSY

Busy

 

 

 

6-22

Wiring Diagrams and Electrical Data