Adding serial terminals

Fixing hung terminals

A terminal is considered ``hung'' if the previous work session is still visible on the display, but it does not respond to keyboard input. To fix a hung terminal:

  1. Wait a minimum of 60 seconds before trying to resurrect the terminal. (If the system is busy, the terminal may not respond immediately to keystrokes because the system response time has increased.)

  2. Press <Ctrl>q to re-enable transmission in case the <Ctrl>s (transmit off) signal was inadvertently pressed.

  3. Check to see that all power cords, keyboard cords, and communications cables are connected.

  4. Reset the terminal hardware by recycling power to the terminal and then reinitialize it by running tset(C) with no arguments.

  5. Verify the terminal set-up mode configuration settings (if available) as described in step 3 of the previous section.

  6. Test the hardware communications by redirecting output from an operating terminal to the locked one as described in the step 6 of previous section.

  7. Check the processes that are running on the locked terminal port with the following command:

    ps -t ttyline

    Stop the process that the user was running when the terminal hung using kill(C). (See ``Killing a process''.) If the program does not die, you must reboot the system to stop the process.

  8. Determine whether the current line characteristic parameters are correct. For example, use the following command to display these values for tty2a:

    stty -a < /dev/tty2a

    You can also compare the stty settings with those of a working terminal.

  9. Reset the serial line characteristics with the following command:

    <Ctrl>j stty sane <Ctrl>j

    If you cannot enter the command on the terminal, you can redirect the stty command from another terminal as follows:

    stty sane < /dev/tty2a

If the ps -t command shows only a getty program, the terminal should display a login prompt. If it does not, check the terminal hardware again.
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© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003