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 6.1. Default stty Settings Used by the LP Print Service

Option

Description

9600

Sets baud to 9600

cs8

Sets 8-bit bytes

cstopb

Sends one stop bit per byte

parity

Does not generate parity

ixon

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

opost

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

olcuc

Do not map lowercase to uppercase

onlcr

Changes linefeed to carriage return/linefeed

ocrnl

Does not change carriage returns into linefeeds

onocr

Outputs carriage returns even at column 0

n10

Provides no delay after linefeeds

cr0

Provides no delay after carriage returns

tab0

Provides no delay after tabs

bs0

Provides no delay after backspace characters

vt0

Provides no delay after vertical tabs

ff0

Provides no delay after form feeds

How to Adjust the Printer Port Characteristics

  1. Log in as superuser, lp, or assume an equivalent role on the print server.

  2. Adjust the printer port characteristics.

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

    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 the stty ( 1 ) man page. Table 6–1 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 6.1. 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 6.2. 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"