Reported 'algebraic loop error' when I was using feed back in logic simulation.

As the Question and the model below. Thanks for your help！

Answer 1

[Ryan G]

http://www.mathworks.com/help/simulink/ug/simulating-dynamic-systems.html#f7-19688

Long story short, the input of the highlighted AND is dependent on the OR which is dependent on the previous AND which is dependent on the aforementioned OR etc etc. Simulink has no way to know which one you want it to process first.