ContDownTimer : sign and redstone

Hi !
Are you able to make a such plugin ? (Countdown)

1_I create a signe with L1 : [CDTimer] ; L2 : 300
2_And I place a redtone poder on one each side of the sign and a pressure plate on one side.
3_If the sign is activated by redstone, the count down starts.
4_When the woundown timer is finish (300 seconds in this example), the sign activates (5) the other redstone with a redstone signal.

http://sketchtoy.com/60056115

Thanks

 

please help me

 

You might want to clarify. You want a sign that activates via redstone after a timer? what would activating the sign do?

 

Thanks
YES ! And when the sign is activated after the timer :
I will do a big door and the redstone will open it ! Something like that ! (I have to do several doors and messages which alert platyers)