Could you recommend to function call event system?

I made a function call event system. but when this code complied, it bring error which is loop problem. So I revised the code to add a unit delay. But this process brings a wrong result. Could you recommend to function call event system?

[Walter Roberson]

See https://blogs.mathworks.com/simulink/2015/07/18/why-you-should-never-break-an-algebraic-loop-with-with-a-memory-block/