The Workflow Of The Printing System; Methods And Protocols For Connecting Printers - Novell LINUX ENTERPRISE SERVER 11 - ADMINISTRATION Administration Manual

10.1 The Workflow of the Printing
System
The user creates a print job. The print job consists of the data to print plus information
for the spooler, such as the name of the printer or the name of the printer queue, and
optionally, information for the filter, such as printer-specific options.
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 filter and back-end to the printer.
The filter converts the data generated by the application that is printing (usually
PostScript or PDF, but also ASCII, JPEG, etc.) into printer-specific data (PostScript,
PCL, ESC/P, etc.). The features of the printer are described in the PPD files. A PPD
file contains printer-specific options with the parameters needed to enable them on the
printer. The filter system makes sure that options selected by the user are enabled.
If you use a PostScript printer, the filter system converts the data into printer-specific
PostScript. This does not require a printer driver. If you use a non-PostScript printer,
the filter system converts the data into printer-specific data. This requires a printer
driver suitable for your printer. The back-end receives the printer-specific data from
the filter then passes it to the printer.
10.2 Methods and Protocols for
Connecting Printers
There are various possibilities for connecting a printer to the system. The configuration
of the CUPS print system does not distinguish between a local printer and a printer
connected to the system over the network. In Linux, local printers must be connected
as described in the manual of the printer manufacturer. CUPS supports serial, USB,
parallel and SCSI connections.
►zseries: Printers and similar devices provided by the z/VM that connect locally with
the IBM System z mainframes are not supported by CUPS or LPRng. On these platforms,
printing is only possible over the network. The cabling for network printers must be
installed according to the instructions of the printer manufacturer. ◄
Printer Operation 115