How can explain the relation between mdlDerivatives output and mdlOutputs in S-function simulink

I am new in Simulink and have a model which is used the S-function. I can not understand how the output of the mdlDerivatives relates to the outputs of the mdlOutputs? In another word, If I want to write a mfile(without using Simulink) what are the states and what are the outputs? I want to write a mfile and find ddq, dq and q but do not get how states in these two parts make the output?(file attached)

Answer 1

[Nick Choi]

As described in this documentation link, 'mdlDerivatives' is an optional method that can be used to compute the derivatives for the continuous states of an S-function at each time step:

https://www.mathworks.com/help/simulink/sfg/mdlderivatives.html

'mdlOutputs' is a required method that computes the outputs for an S-function block at each time step

https://www.mathworks.com/help/simulink/sfg/mdloutputs.html

Regarding how the sections of an S-function relate to each other, the following documentation page provides some useful information on how S-functions work and it also describes how the inputs, outputs and states of a block are related:

https://www.mathworks.com/help/simulink/sfg/how-s-functions-work.html