If an unconfigured local printer is detected, YaST starts automatically to configure it. YaST can configure the printer automatically if the parallel or USB port can be set up automatically and the connected printer can be detected. The printer model must also be listed in the database used during the automatic hardware detection.

If the printer model is unknown or cannot be automatically detected, configure it manually. There are two possible reasons why a printer is not automatically detected:

23.4.1.1. Configuring Manually¶

To manually configure the printer, select Hardware+Printer in the YaST control center. This opens the main Printer Configuration window, where the detected devices are listed in the upper part. The lower part lists any queues configured so far (refer to Section 23.1, “The Workflow of the Printing System” for more information about print queues). If no printer was detected, both parts of the configuration window are empty. Use Edit to change the configuration of a listed printer or Add to set up a printer not automatically detected. Editing an existing configuration uses the same dialogs as in Procedure 23.1, “Adding a Local Printer Manually”.

In Printer Configuration, you can also Delete an existing entry. Clicking Other opens a list with advanced options. Select Restart Detection, to manually start the automatic printer detection. If more than one printer is connected to the machine or more than one queue is configured for a printer, you can mark the active entry as the default. CUPS Expert Settings and Change IPP Listen are advanced configuration options— refer to Chapter 23, Printer Operation for details.

Procedure 23.1. Adding a Local Printer Manually¶

	YaST Print Test
To make sure that everything works correctly, the crucial configuration steps can be checked with the print test function of YaST. The test page also provides important information about the configuration tested. If the output is garbled, for example, with several pages almost empty, you can stop the printer by first removing all paper then stopping the test from YaST.

1. Start YaST and choose Hardware+Printer to open the Printer Configuration dialog.

2. Click Add to open the Printer Type window.

3. Choose Directly Connected Printers.

4. Select the port to which the printer is connected (usually USB or parallel port) and choose the device in the next configuration screen. It is recommended to Test the Printer Connection at this point. If problems occur, select the correct device or choose Back to return to the previous dialog.

5. In Queue Name, set up a print queue. Specifying a Name for Printing is mandatory. It is recommended to choose a recognizable name—with this name, you can later identify the printer in the printing dialogs of applications. Use Printer Description and Printer Location to further describe the printer. This is optional, but useful if you have more than one printer connected to the machine or if you set up a print server. Do Local Filtering should be checked—it is needed for local printers.

6. In Printer Model, specify the printer by Manufacturer and Model. If your printer is not listed, you can try UNKNOWN MANUFACTURER from the manufacturer list and select an appropriate standard language (the set of commands controlling the printer) from the model list (refer to your printer's documentation to find out which language your printer understands). If this does not work, refer to Section 23.4.1.2, “Adding PPD Files with YaST” for another possible solution.

7. The Configuration screen lists a summary of the printer setup. This dialog is also shown when editing an existing printer configuration from the start screen of this YaST module.

   Figure 23.1. Printer Configuration Summary¶
   
   

   The summary contains the following entries, which you can also modify with Edit:

   • Name and basic settings, Printer Model, and Connection let you change entries made while following this procedure.

   • Refer to Section 23.4.1.3, “Choosing an Alternative PPD File with YaST” for details on PPD file.

   • With Filter settings fine-tune the printer setup. Configure options like Page Size, Color Mode, and Resolution here.

   • By default, every user is able to use the printer. With Restriction settings, list users that are forbidden to use the printer or list users that are allowed to use it.

   • With State and banner settings you can, for example, deactivate the printer by changing its state and specify whether a page with a Starting Banner or Ending Banner is printed before or after each job (the default is not to print them).

Network printers are not detected automatically. They must be configured manually using the YaST printer module. Depending on your network setup, you can print to a print server (CUPS, LPD, SMB, or IPX) or directly to a network printer (preferably via TCP). Ask your network administrator for details on configuring a network printer in your environment.

Apart from setting CUPS options with YaST when configuring a network printer, CUPS can be configured with command line tools like lpadmin and lpoptions. You need a device URI consisting of a back-end, such as USB, and parameters, like /dev/usb/lp0. For example, the full URI could be parallel:/dev/lp0 (printer connected to the first parallel port) or usb:/dev/usb/lp0 (first detected printer connected to the USB port).

With lpadmin, the CUPS server administrator can add, remove, or manage class and print queues. To add a print queue, use the following syntax:

lpadmin -p queue -v device-URI -P PPD-file -E

Then the device (-v) is available as queue (-p), using the specified PPD file (-P). This means that you must know the PPD file and the name of the device to configure the printer manually.

Do not use -E as the first option. For all CUPS commands, -E as the first argument sets use of an encrypted connection. To enable the printer, -E must be used as shown in the following example:

lpadmin -p ps -v parallel:/dev/lp0 -P \
/usr/share/cups/model/Postscript.ppd.gz -E

The following example configures a network printer:

lpadmin -p ps -v socket://192.168.2.202:9100/ -P \
/usr/share/cups/model/Postscript-level1.ppd.gz -E

For more options of lpadmin, see the man page of lpadmin(1).

During printer setup, certain options are set as default. These options can be modified for every print job (depending on the print tool used). Changing these default options with YaST is also possible. Using command line tools, set default options as follows:

When a normal user runs lpoptions, the settings are written to ~/.lpoptions. However, root settings are written to /etc/cups/lpoptions.

After having performed a default installation of SUSE Linux Enterprise, SuSEfirewall2 is active and the external network devices are configured to be in the External Zone which blocks incoming traffic. These default settings have to be adjusted when using CUPS. More information about the SUSEfirewall2 configuration is available in Section 43.4, “SuSEfirewall2”.

The YaST printer configuration sets up the queues for CUPS using only the PPD files installed in /usr/share/cups/model. To find the suitable PPD files for the printer model, YaST compares the vendor and model determined during hardware detection with the vendors and models in all PPD files available in /usr/share/cups/model on the system. For this purpose, the YaST printer configuration generates a database from the vendor and model information extracted from the PPD files. When you select a printer from the list of vendors and models, receive the PPD files matching the vendor and model.

The configuration using only PPD files and no other information sources has the advantage that the PPD files in /usr/share/cups/model can be modified freely. The YaST printer configuration recognizes changes and regenerates the vendor and model database. For example, if you only have PostScript printers, normally you do not need the Foomatic PPD files in the cups-drivers package or the Gimp-Print PPD files in the cups-drivers-stp package. Instead, the PPD files for your PostScript printers can be copied directly to /usr/share/cups/model (if they do not already exist in the manufacturer-PPDs package) to achieve an optimum configuration for your printers.

These printers do not support any common printer language and can only be addressed with special proprietary control sequences. Therefore they can only work with the operating system versions for which the manufacturer delivers a driver. GDI is a programming interface developed by Microsoft* for graphics devices. Usually the manufacturer delivers drivers only for Windows and because the Windows driver uses the GDI interface, these printers are also called GDI printers. The actual problem is not the programming interface, but the fact that these printers can only be addressed with the proprietary printer language of the respective printer model.

Some GDI printers can be switched to operate either in GDI mode or one of the standard printer languages. See the manual of the printer whether it is possible. Some models require a special Windows software to do the switch (note that the Windows printer driver may always switch the printer back into GDI mode when printing from Windows). For other GDI printers there are extension modules for a standard printer language available.

Some manufacturers provide proprietary drivers for their printers. The disadvantage of proprietary printer drivers is that there is no guarantee that these work with the installed print system and that they are suitable for the various hardware platforms. In contrast, printers that support a standard printer language do not depend on a special print system version or a special hardware platform.

Instead of spending time trying to make a proprietary Linux driver work, it may be more cost-effective to purchase a supported printer. This would solve the driver problem once and for all, eliminating the need to install and configure special driver software and obtain driver updates that may be required due to new developments in the print system.

If the manufacturer-PPDs package does not contain any suitable PPD file for a PostScript printer, it should be possible to use the PPD file from the driver CD of the printer manufacturer or download a suitable PPD file from the Web page of the printer manufacturer.

If the PPD file is provided as a zip archive (.zip) or a self-extracting zip archive (.exe), unpack it with unzip. First, review the license terms of the PPD file. Then use the cupstestppd utility to check if the PPD file complies with “Adobe PostScript Printer Description File Format Specification, version 4.3.” If the utility returns “FAIL,” the errors in the PPD files are serious and are likely to cause major problems. The problem spots reported by cupstestppd should be eliminated. If necessary, ask the printer manufacturer for a suitable PPD file.

The safest approach is to connect the printer directly to the first parallel port and to select the following parallel port settings in the BIOS:

If the printer cannot be addressed on the parallel port despite these settings, enter the I/O address explicitly in accordance with the setting in the BIOS in the form 0x378 in /etc/modprobe.conf. If there are two parallel ports that are set to the I/O addresses 378 and 278 (hexadecimal), enter these in the form 0x378,0x278.

If interrupt 7 is free, it can be activated with the entry shown in Example 23.1, “ /etc/modprobe.conf: Interrupt Mode for the First Parallel Port ”. Before activating the interrupt mode, check the file /proc/interrupts to see which interrupts are already in use. Only the interrupts currently being used are displayed. This may change depending on which hardware components are active. The interrupt for the parallel port must not be used by any other device. If you are not sure, use the polling mode with irq=none.

alias parport_lowlevel parport_pc
options parport_pc io=0x378 irq=7

For the print system, the print job is completed when the CUPS back-end completes the data transfer to the recipient (printer). If the further processing on the recipient fails, for example, if the printer is not able to print the printer-specific data, the print system does not notice this. If the printer is not able to print the printer-specific data, select a different PPD file that is more suitable for the printer.

If the data transfer to the recipient fails entirely after several attempts, the CUPS back-end, such as USB or socket, reports an error to the print system (to cupsd). The back-end decides whether and how many attempts make sense until the data transfer is reported as impossible. Because further attempts would be in vain, cupsd disables printing for the respective queue. After eliminating the cause of the problem, the system administrator must reenable printing with the command /usr/bin/enable.

If a CUPS network server broadcasts its queues to the client hosts via browsing and a suitable local cupsd is active on the client hosts, the client cupsd accepts print jobs from applications and forwards them to the cupsd on the server. When cupsd accepts a print job, it is assigned a new job number. Therefore, the job number on the client host is different from the job number on the server. Because a print job is usually forwarded immediately, it cannot be deleted with the job number on the client host, because the client cupsd regards the print job as completed as soon as it has been forwarded to the server cupsd.

To delete the print job on the server, use a command such as lpstat -h cups.example.com -o to determine the job number on the server, provided the server has not already completed the print job (that is, sent it completely to the printer). Using this job number, the print job on the server can be deleted:

cancel -h cups.example.com queue-jobnnumber

Print jobs remain in the queues and printing resumes if you switch the printer off and on or shut down and reboot the computer during the printing process. Defective print jobs must be removed from the queue with cancel.

If a print job is defective or an error occurs in the communication between the host and the printer, the printer prints numerous sheets of paper with unintelligible characters, because it is unable to process the data correctly. To deal with this, follow these steps:

Use the following generic procedure to locate problems in the CUPS print system: