Simulink code generation: variable subsystem and its code

This paper studies Simulink Variable subsystem in , And its generated conditional compiled code .

1 Problem introduction

Different projects in the work correspond to different needs , Then different requirements may need to be implemented with different model strategies . here , You can use Variant Subsystem modeling , And control the subsystem through which a project outputs results through parameters . also , The generated code can also be expressed in the form of macro definitions .

2 Modeling examples

This chapter demonstrates the modeling method of variable subsystem .

1） First , stay Matlab Create a new workspace Simulink.Parameter Parameter object , Take it as the variable parameter that controls the variable subsystem later ;

among , Who should be StorageClass by Define, Corresponding C Macro definition in code . This is done in order to generate the form of macros later when generating code .

2） Add a variable subsystem to the blank model , Set its properties as follows ：

Right click subsystem , Click on Block Parameters, You can open the configuration interface of the subsystem , Set to the following configuration ;

In the table Name Column , Represents different subsystem names in the subsystem , Set as Gain_2 and Gain_3, hinder Variant control Indicates which subsystem runs in the variable subsystem with parameters a system . When P_Condition2 perform Gain_2 Subsystem , When P_Condition3 perform Gain_3 Subsystem . Save and exit .

3） Double click to enter the variable subsystem , You can see that there are two subsystems , And careful observation can be found that the input and output ports are different .

The names of the two subsystems correspond to Name To configure , The input and output ports should be connected with the outside port bring into correspondence with , And the signal line cannot be connected .

4） In the two subsystems Gain modular , But one parameter is 2, The other is 3;


As set in the first step P_Condition Values for 2, So the top Gain_2 The subsystem is solid , Below Gain3 Subsystem is shadow .

5） Here we are , Modeling has been completed . You can verify that , Add an input at the top of the model as a constant 1, Output is display modular ;

When P_Condition Values for 2 when ,Update After the model , Output is 2;

When P_Condition Values for 3 when ,Update After the model , Output is 3;

That means , Which way to go in the variable subsystem , According to the parameters P_Condition Controlled . In practice , For different projects , Revise it P_Condition The value of the parameter , Different control logics and strategies can be implemented .

3 Code generation

Replace the top-level model with Inport and Outport port ,Ctrl + B The generated code .

stay P_Macro.h In file , Generated P_Condition The macro definition of , Values for 2;

stay step Function , By judgment P_Condition To determine which assignment statement to execute , And is #if Conditional judgment of form , instead of C In language if Conditional statements . This has the advantage of , When the compiler compiles this code , You can skip P_Condition == 3 The following statement , Thus saving the controller flash resources .

4 summary

The variable subsystem can judge the condition , To determine the internal implementation of different logic , Generated code can also be generated in the form of macros .

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