Display Power Management Signaling

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Display Power Management Signaling (DPMS) enables power saving behaviour of monitors when the computer is not in use. The time of inactivity before the monitor enters into a given saving power level, standby, suspend or off, can be set as described in DPMSSetTimeouts(3). Note that DPMS was developed for CRT monitors, and on LCD displays, there is normally no difference between the standby, suspend and off modes.

Linux console

To alter the terminal, setterm issues terminal-recognized escape codes. Essentially it just writes/echos the terminal sequences to the current terminal device, whether that be in screen, a remote ssh terminal, console mode, serial consoles, etc. Its syntax (where 0 disables): 

$ setterm --blank [0-60|force|poke]
$ setterm --powersave [on|vsync|hsync|powerdown|off]
$ setterm --powerdown [0-60]
Note:
  • Console blanking alone does not enable DPMS power saving. Console blanking is disabled by default. [1]
  • setterm --powerdown does not seem to have any effect when the APM_DISPLAY_BLANK kernel configuration option is not enabled. [2]
  • Console blanking can also be enabled by the consoleblank kernel parameter. See the kernel documentation for details.

To see the escape codes used, pipe the output as follows: 

$ setterm --powerdown 2>&1 | exec cat -v 2>&1 | sed "s/\\^\\[/\\\\033/g"

To modify a specific terminal, redirect the escape codes to it (with write permission): 

$ setterm --powerdown 0 >> /dev/tty3
Note: >> is used instead of >. For permission issues using sudo in a script or something, you can use tee to append the output of setterm to the tty device, which tty's let appending sometimes but not writing.

Xorg

Configuration

Note: As of Xorg 1.8 DPMS is auto detected and enabled if ACPI is also enabled at kernel runtime.

To fully disable DPMS, create a configuration file: 

/etc/X11/xorg.conf.d/10-extensions.conf
Section "Extensions"
    Option "DPMS" "false"
EndSection

If you simply want to adjust the delays, change the duration (in minutes): 

/etc/X11/xorg.conf.d/10-serverflags.conf
Section "ServerFlags"
    Option "StandbyTime" "10"
    Option "SuspendTime" "20"
    Option "OffTime" "30"
EndSection
Note: If the OffTime option does not work, use screen blanking (i.e. BlankTime) instead, which will keep the monitor turned on with a black image.

Runtime settings

It is possible to turn off your monitor with the xset command which is provided by the xorg-xset package.

Examples:

Command Description
xset s off Disable screen saver blanking
xset s 3600 3600 Change blank time to 1 hour
xset -dpms Turn off DPMS
xset s off -dpms Disable DPMS and prevent screen from blanking
xset dpms force off Turn off screen immediately
xset dpms force standby Standby screen
xset dpms force suspend Suspend screen

To query the current settings: 

$ xset q
...
Screen Saver:
  prefer blanking:  yes    allow exposures:  yes
  timeout:  600    cycle:  600
DPMS (Energy Star):
  Standby: 600    Suspend: 600    Off: 600
  DPMS is Enabled
  Monitor is On

See xset(1) for all available commands.

Note:
  • XScreenSaver and xfce4-power-manager use their own DPMS settings and override xset configuration. See XScreenSaver#DPMS and blanking settings and Xfce#Display blanking for more information.
  • If using the command manually in a shell you may need to prefix it with sleep 1; for it to work correctly, for example sleep 1; xset dpms force off
  • xset dpms 0 0 0, which sets all the DPMS timeouts to zero, could be a better way to "disable" DPMS, since the effect of -dpms would be reverted when, for example, turning off the screen with xset dpms force off.
  • If using xset in xinitrc does not work, specify settings within a file in /etc/X11/xorg.conf.d/, see #Configuration.

See also