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AIX Version 4.3 AIXwindows Programming Guide

Appendix C. Display Power Management

Display Power Management (DPM) is available for display devices that conform to the VESA Display Power Management Signaling standard, when attached to graphics display adapters that also support that standard.

The VESA standard defines four levels of power consumption:

In full-on mode, the display is in its full power (normal) state with no power savings. The standby, suspend, and off states are the low-power states in order of increasing power savings.

Note: Refer to your display and graphics display adapter product information to determine if your products support the DPM function.

You can define when a supporting display enters each of the power management states through SMIT. Select Devices from the main menu, then Graphic Display, and then Display Power Management. In this dialog there are three time-out values corresponding to each of the low-power states. These time-outs define the interval from the last operator input until the corresponding power management state is entered.

The default values for these time-outs are:

Standby 20 minutes
Suspend 30 minutes
Off 40 minutes

The DPM function is supported in both the LFT and graphics modes. In AIXwindows mode, changes to the time-out values in ODM take effect after the next time the screen saver is deactivated, unless the user has specified power management options on the X Server command line. For LFT mode, changes to the time-out values take effect after the next reboot.

For displays not supporting VESA power management, the AIXwindows screen saver function continues to provide the screen-saving function. A screen-blanking function has been added to LFT mode to reduce burn-in and thus extend the life of the display.

AIXwindows users can also override the DPM time-outs with the -pm flag when AIXwindows is started. The -pm flag allows three parameters, corresponding to the three time-out values, for example:

-pm t1 t2 t3

The time-out values are specified in minutes. The command:

xinit -s 10 -pm 20 30 40

indicates that AIXwindows is to be run with the screen saver activated after 10 minutes and the display to be put in standby state at 20 minutes, suspend state at 30 minutes, and the off state at 40 minutes from the last detected input event.

The DPM time-out function is disabled if either the screen saver is disabled (-s 0 ) or the first DPM (standby) time-out is set to 0 (zero).

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