while loop: execution time and continuos updated - elapsed time VI back to false?

Dear all, 

I want to control the execution time of a while loop. I want the user to have the possibility to decide for how long he wants to execute the while loop. THe while loop is used to update some values, so it should continuosly run, not just run once and then wait (which I could easily do using the timing functions).

I used the elapsed time VI like suggested in this post:

http://forums.ni.com/t5/LabVIEW/How-to-create-a-time-control-for-while-loop/m-p/2530212/highlight/false#M767929

and works ok, but the while loops are integrated into another for loop, and when the for goes to next iteration, the elapsed time boolean output is fixed to true and it does not execute the while (I think this is the problem). 

Is it possible to set the boolean output of the elapsed time VI back to false once the time target has been reached? This would solve my problem, I think...

I attach a part of my VI, even if I don't know it could be useful to you...

Thanks for your help