It would be helpful to know what kind of model this is. Continuous or discreet? variable or fixed step size?
In general, I recommend you accumulate the true values with an integrator or counter as is appropriate to your model, and reset that to zero whenever the value is false. You can then test the output of the integrator to see if the truth table output has been true for 5 or more seconds.
See this hastily-concocted model for an example:
