Check if display is powered on

Is there a way to check if display is powered on in linux. I tried xrandr and xset but none of these two give me if any information about monitor power. using xrandr we can identify if the vga cable is connected but not if power is connected. I need this because many of our Lab sy开发者_运维问答stems keep lying unused just because some one pulls out the power cable or so.

-- Jatin