System Administration Guide: Printing

Adjusting Printer Port Characteristics

The printer port characteristics set by the LP print service must be compatible with the printer communication settings. If the default printer port settings provided by the LP print service do not work with a printer, refer to the printer manual from the manufacturer to determine what settings the printer requires from the LP print service. Use the stty command to set and display printer communication settings.

The following table shows the default stty settings that are used by the LP print service.

Table 7–1 Default stty Settings Used by the LP Print Service




Sets baud to 9600 


Sets 8-bit bytes 


Sends one stop bit per byte 


Does not generate parity 


Enables XON/XOFF (also known as START/STOP or DC1/DC3) 


Does “output post-processing” using all the settings that follow in this table 


Do not map lowercase to uppercase 


Changes linefeed to carriage return/linefeed 


Does not change carriage returns into linefeeds 


Outputs carriage returns even at column 0 


Provides no delay after linefeeds 


Provides no delay after carriage returns 


Provides no delay after tabs 


Provides no delay after backspace characters 


Provides no delay after vertical tabs 


Provides no delay after form feeds 

ProcedureHow to Adjust the Printer Port Characteristics

  1. Become superuser or assume an equivalent role.

    Roles contain authorizations and privileged commands. For more information about roles, see Configuring RBAC (Task Map) in System Administration Guide: Security Services.

  2. Adjust the printer port characteristics.

    # lpadmin -p printer-name -o "stty=options"

    Specifies the name of the printer for which you are adjusting the port characteristics.

    -o “stty=options”

    Sets the port characteristic (stty option) specified by options. You can change more than one stty option setting with this command. Enclose each option in single quotation marks, and use a space to separate the options. For a complete list of options, see thestty(1) man page. Table 7–1 shows the default stty settings used by the LP print service.

  3. Verify that the printer port characteristics have been changed.

    # lpstat -p printer-name -l

Example 7–1 Adjusting the Printer Port Characteristics

This example shows how to set the port characteristics for the printer luna. The parenb option enables parity checking/generation. The parodd option sets odd parity generation. The cs7 option sets the character size to 7 bits.

# lpadmin -p luna -o "stty='parenb parodd cs7'"

Example 7–2 Setting the Terminal Baud Rate

This example shows how to set the terminal baud rate to 19200 for the printer venus.

# lpadmin -p venus -o "stty=19200"