So you want a func_movelinear to raise up 300hu, stay there for a moment, then drop back down again.
Set the Move Direction to '0 90 0' and the move distance to 300.
On the Output tap, give it the following:
Code:
My Output | Target Entity | Target Input | Parameter | Delay
OnFullyOpen | !self | Close | <none> | 2.00
All you will need to do is send the func_movelinear an 'Open' input and it will raise up.