Lexmark 33S0300 Technical Reference - Page 335

8-21 Interfaces Using the RS-232C Serial Interface This section describes how to use the RS-232C serial interface. 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. RS-232C Serial Cable Pin Assignments The RS-232C serial cable appears as follows: 25-Pin 13 25 D-Shell (Male) 25-Pin D-Shell 13 25 (Female) 1 14 Printer Side 1 14 Computer Side 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. 4 RTS Out Request to Send. The printer sets this signal high and the 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. 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.