Increasing vector value over time

Hi Guys, i’m kinda new to ue4. I want to have an emissive value increase and decrease over time.
First, i made a dynamic instance material, and the emissive value gets to 100 from 0 when the collisionbox gets hit. Fine ! but i find it to hard, and want to have a transition between 0 and 100. I tried to follow those two answers :

Unfortunatly my understandings of the blueprint grammar are limited right now. here is a snap from my bp (which also includes sounds when Box gets hit).

I don’t get how “get float value” takes informations from my curvefloat (which goes to 0,0 to 2,100) which has a time information AND needs an “in time” information…

Thanks for your time and answers