Lexmark X940E - Using the RS-232 C Serial Interface

Interfaces
8-11
Serial Interface
The serial interface allows data to flow back and forth between the computer and the
printer. However, the serial interface transfers data at a slower rate than the parallel
interface.
If a serial connector is required, you may be able to install an RS-232C Serial Interface
Card, an External Serial Adapter, or an RS-232C Serial/Parallel 1284-C Interface
Card. See your printer documentation for more information.
When using the serial interface, your printer has the following differences from the
serial interface on some other printers:
• The printer returns XON/XOFF with 2 stop bits in all cases.
• The printer does not support DTR inversion.
Using the RS-232C Serial 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.
3 RXD In Receive Data. The pin receives data from your computer or
terminal.
2513
141
2513
141
25-Pin
D-Shell
(Female)
25-Pin
D-Shell
(Male)
Computer
Side
Printer
Side