Serial Cable Pin Assignments (RS-232C)

The following illustration shows the RS-232C serial cable:

 

25-Pin

25-Pin

 

 

 

Male

D-shell

 

 

13

25

Female

25

13

1

14

14

1

 

Serial Adapter Side

Computer Side

 

RS-232C Serial Connector Pin Assignments

Pin

Signal

Description

 

 

 

2

TXD

This line transmits data from the printer to the host. The data

 

(Transmit Data)

characteristics are specified by the function menu settings which are

 

 

read only during a Power On Reset (POR). The only data

 

 

transmitted are XON (x’11’) and XOFF (x’13’) signals. Transmission

 

 

occurs only when CTS is high.

 

 

 

3

RXD

This line receives data from the host. The serial interface accepts

 

(Receive Data)

data only when DSR is On.

 

 

 

4

RTS

This line is set high and remains high even after the serial interface

 

(Request to Send)

finishes its POR.

 

 

 

5

CTS

This line is monitored only if the XON/XOFF protocol is selected

 

(Clear to Send)

because transmission occurs only when CTS is high.

 

 

 

6

DSR

DSR is another method of providing data integrity. Data is accepted

 

(Data Set Ready)

only when DSR is high.

 

 

 

20

DTR

This line is set high after the serial interface finishes its POR

 

(Data Terminal Ready)

sequence. However, if you select DTR pacing handshake protocol,

 

 

this line is used to indicate to the host whether or not the printer is

 

 

ready to receive any more data.

 

 

 

Section 6: Using the Printer Interface

97

 

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Image 97
Lexmark 248X, 249X manual Serial Cable Pin Assignments RS-232C, Following illustration shows the RS-232C serial cable