MATLAB: Hidden constants in SIMULINK

MATLABsimulinksimulink constant blocks hidden linked script

Hello

I am attempting to modify someone else's Simulink model. There are constant blocks with constant names as opposed to numbers. For example, rotor RPM input is 'Omega'.

In my experience, this should be defined in the workspace through some appropriate script file. In this model it will run fine without any script file and without any constants defined in the workspace. After the simulation has run no constants appear in the workspace.

Please tell me where the simulink model might be getting these values from! Thanks

Best Answer

They could be in the Model Workspace, which is a great place to "protect" variables from the MATLAB base workspace.

You can go there by selecting View > Model Explorer, or Ctrl+H on Windows. Once you're there, you can navigate through your open model and find the Model Workspace section. See if those variables are there.

Another way to get the Model Explorer opened up is by right-clicking the model and selecting Find Referenced Variables. That will show you the locations of all variables used by that model, and where they are.

- Sebastian

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MATLAB: How to define which objects from data dictionary are used in the model which linked on that data dictionary

If a model has its design data defined in a data dictionary, you can click on the icon in the lower-left corner of the model window to open the data dictionary in the Model Explorer. And you can see Design Data under the data dictionary inside the Model Hierarchy pane.

To identify which objects from the data dictionary are not used by the model, right-click Design Data and select Find Unused Variables. You will be asked to Update diagram. After that, the Model Explorer displays unused objects from the data dictionary.

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The MATLAB has several different workspaces. Simulink model has its own workspace: https://www.mathworks.com/help/simulink/ug/using-model-workspaces.html. The workspace you see on the main MATLAB window is called the base workspace. The method to change a variable in base workspace depends on what you are trying to do. One way is to use the To Workspace block: https://www.mathworks.com/help/simulink/slref/toworkspace.html. The other is to use evalin and assignin functions, as shown in the attached file. To run this model, define a variable x in the base workspace by running

x = 5

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Best Answer

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