Operation Manual
At least one dedicated printer queue exists for every printer. The spooler holds the print
job in the queue until the desired printer is ready to receive data. When the printer is
ready, the spooler sends the data through the lter and back-end to the printer.
The lter converts the data generated by the application that is printing (usually
PostScript or PDF, but also ASCII, JPEG, etc.) into printer-specic data (PostScript,
PCL, ESC/P, etc.). The features of the printer are described in the PPD les. A PPD
le contains printer-specic options with the parameters needed to enable them on the
printer. The lter system makes sure that options selected by the user are enabled.
If you use a PostScript printer, the lter system converts the data into printer-specic
PostScript. This does not require a printer driver. If you use a non-PostScript printer,
the lter system converts the data into printer-specic data. This requires a printer
driver suitable for your printer. The back-end receives the printer-specic data from
the lter then passes it to the printer.
11.2 Methods and Protocols for
Connecting Printers
There are various possibilities for connecting a printer to the system. The conguration
of the CUPS print system does not distinguish between a local printer and a printer
connected to the system over the network. For more information about the printer
connection, read the article CUPS in a Nutshell in the Support Database at http://
old-en.opensuse.org/SDB:CUPS_in_a_Nutshell.
WARNING: Changing Cable Connections in a Running System
When connecting the printer to the machine, do not forget that only USB de-
vices can be plugged in or unplugged during operation. To avoid damaging
your system or printer, shut down the system before changing any connections
that are not USB.
Printer Operation 151










