Lexmark C720 Guia De Referência

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. 

Some printers have a standard serial connector for RS-232C serial interface. If a serial 
connector is not standard, you may be able to install a Tri-Port interface option card. 
Refer to your printer user documentation for more information.

The Tri-Port interface option card supports two serial interface standards: RS-232C 
and RS-422. The RS-422 serial interface provides more protection from electrical 
noise than RS-232.

Use RS-232C serial interface if the printer is more than 3.04 m (10 ft) from the 
computer but less than 15.24 m (50 ft) away. (You can also use a 6.1 m (20 ft) Lexmark 
cable to connect a printer and a computer located up to 20 feet apart.)

Use RS-422 if your computer is more than 15.24 m (50 ft) away from the printer. You 
may need to purchase an RS-422 adapter and software for your computer to run 
RS-422. Refer to your computer documentation for more information. You also need 
to purchase a custom cable for the serial interface, because serial RS-422 interface 
pinouts are usually unique to each computer.

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.

This section describes how to use the RS-232C serial interface. If you are using 
RS-422, see “Using the RS-422 Serial Interface” on page 8-46.

Use Lexmark serial cable P/N 1038693 (15.24 m or 50 ft) to connect the serial 
interface.