Lexmark X644e User Guide
Interfaces
8-19
How to Connect the RS-232C Serial Interface
Use Lexmark serial cable P/N 1038693 (15.24 m or 50 ft) to connect the serial
interface.
interface.
RS-232C Serial Cable Pin Assignments
The RS-232C serial cable appears as follows:
Table 8-3: Dedicated Serial Connector Pin Assignments (RS-232C)
Pin
Signal
Direction
Description
1
GND
Frame Ground
2
TXD
Out
Transmit Data. The pin transmits data to your computer or
terminal.
terminal.
3
RXD
In
Receive Data. The pin receives data from your computer or
terminal.
terminal.
4
RTS
Out
Request to Send. The printer sets this signal high and the
signal remains high while the printer is on.
signal remains high while the printer is on.
5
CTS
In
Clear to Send. This pin is optionally used for serial data flow
control protocol when in serial mode.
control protocol when in serial mode.
6
DSR
In
Data Set Ready. This pin is optionally used for data
validation, depending on the Honor DSR setting, or flow
control, depending on the Serial Protocol setting.
validation, depending on the Honor DSR setting, or flow
control, depending on the Serial Protocol setting.
7
GND
Logic Ground
20
DTR
Out
Data Terminal Ready. This pin is optionally used for serial
data flow control protocol when in serial mode.
data flow control protocol when in serial mode.
25
13
14
1
25
13
14
1
25-Pin
D-Shell
(Female)
D-Shell
(Female)
25-Pin
D-Shell
(Male)
D-Shell
(Male)
Computer
Side
Printer
Side