Lexmark C752 Technical Reference page 345

Serial Cable Pin Assignments (RS-422)
The RS-422 serial cable appears as follows:
Pin assignments for this 25-pin connector are shown in Table 8-7. You can set the
polarity of these signals from the printer operator panel or through MarkVision
Professional.
Table 8-7: Dedicated Serial Connector Pin Assignments (RS-422)
Pin
1
15
17
19
25
The following illustration shows how the pins are used:
25 13
25-Pin
(Male)
Printer
1 14
Side
Signal
GND
RXD*
RXD
TXD*
TXD
Printer
Side
25-Pin
Connector
* Positive Signal
8-36
Direction Description
Logic Ground
In Receive Data
In Receive Data
Out Send (transmit) Data
Out Send (transmit) Data
Interfaces
Computer
Side
Customized
Connector
(Optional)