How to model a delay in a boolean equation

Hi,

I am a newer in Simulink.

I have a Simulink block (Block1) which represent a boolean equation. If the output of Block1 is 1 after N-seconds an input of another Simulink Block (Block2) must be setted to 1 and must be 1 until the output of Block 1 is 1. In the other cases the input of Block2 must be 0 also in the case that during the N-seconds the output of Block 1 is setted to 0.

How can I model this behaviour?

Thanks a lot for your replies

Andrew

P.S. The Block2 represents another boolean equation and I use MATLAB R2011b