DPMS(Display Power Management Signalling)

Display Power Management Signaling (DPMS) is a standard to reduce power consumption in monitors. Typically, both the monitor and the video card must support the DPMS standard in order to receive any benefit from it. DPMS specifies four modes of operation (in order of increasing power savings):

"Normal", "Standby", "Suspend" and "Off". Two signal lines, "Horizontal Sync" and "Vertical Sync" provide a method for signalling these four different states to a DPMS monitor.