Lexmark X644e User Guide

Parallel Mode 2 is a feature available for many Lexmark printers. The factory default 
setting is 

.

The timing required by the printer is clearly indicated in “Standard Protocol Data 
Transfer Sequence” on page 8-11. This is the classic Centronics interface timing.

By setting 

 to 

 from the printer operator panel, through MarkVision 

Professional, or through a PJL command, the printer changes when data is valid. 
Once 

 is set to 

, the printer takes data from the host computer at the 

trailing edge of STROBE. This is the last possible host driven transition where data 
should be valid.

If 

 is 

, the printer automatically turns 

to 

, 

eliminating any IEEE 1284 data flow control.

You may find this feature helpful when having data transfer reliability 
problems.

The following diagram illustrates the STROBE receiver for the Lexmark X644e and 
X646e.

74LVC161284

470 ±10%

Connector 
Pin

GND