Nonlinear plant in simulink

I need to model a nonlinear equation in simulink as below:

I think I need to use s-function block, in order to do that I need to code that equation as a function in .m file?

Answer 1

[Andy Bartlett]

The key is to model Y(k+1) to Y(k) using a unit delay.

The output of the unit delay is the input value from one time step early.

Input Output

Y(k+1) Y(k)

then just wire-up the math around that.

[Ömer Ergün]

Thanks for the tip, and where should I wire-up the math equation, in matlab fcn block or in mscript or can I just made a model with fundamental simulink blocks ...?

For example I generated this model, is it true?

(u is the signal comes from PID and the y is the output feedback)

[Walter Roberson]

There is no point having the 1/z in two different places. You should have it only once and split back the signal after the 1/z

I am not sure that you should be mux'ing the two values; I think you should probably be having the u(i) and 1/z flowing directly into the mathematics block as separate inputs.