Contents Overview of s-Functions What Is an S-Function? 2 Using S-Functions in Models 1-3 Passing Parameters to S-Functions 1-4 When to Use an s-Function 15 How S-Functions Work l-6 Mathematics of simulink blocks Simulation Stages... l-6 S-Function Callback methods 1-9 Implementing S-Functions 1-10 M-File s-Functions l-10 MEX-File S-Functions l-11 S-Function Concepts l-13 Direct Feedthrough 1-13 Dynamically Sized Arrays l-13 Setting Sample Times and Offsets 1-15 S-Function Examples l-18 Writing M s-Functions Introduction 2-2 S-Function Arguments 2-2 S-Function Outputs Defining S-Function Block Characteristicsi Contents 1 Overview of S-Functions What Is an S-Function? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 Using S-Functions in Models . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 Passing Parameters to S-Functions . . . . . . . . . . . . . . . . . . . . . . 1-4 When to Use an S-Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5 How S-Functions Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6 Mathematics of Simulink Blocks . . . . . . . . . . . . . . . . . . . . . . . . 1-6 Simulation Stages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6 S-Function Callback Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9 Implementing S-Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10 M-File S-Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10 MEX-File S-Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11 S-Function Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13 Direct Feedthrough . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13 Dynamically Sized Arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13 Setting Sample Times and Offsets . . . . . . . . . . . . . . . . . . . . . . 1-15 S-Function Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-18 2 Writing M S-Functions Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 S-Function Arguments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 S-Function Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3 Defining S-Function Block Characteristics . . . . . . . . . . . . . . 2-5