Define System Object for Use in Simulink

Develop System Object for Use in MATLAB System Block

You can develop a System object™ for use in a MATLAB System block and interactively preview the block dialog box. This feature requires Simulink^®.

With the System Block editing options, the MATLAB^® Editor inserts predefined code into the System object. This coding technique helps you create and modify your System object faster and increases accuracy by reducing typing errors.

Using these options, you can also:

View and interact with the block dialog box design using System Block > Launch Mask Editor > Preview Dialog as you define the System object.
Add dialog box customization methods. If the block dialog box is open when you make changes, the block dialog design preview updates the display on saving the file.
Add icon customization methods.

The System Block menu drop-down option is displayed.

The Preview Dialog option is selected from the Mask Editor toolstrip.

Define Block Dialog Box for Plot Ramp

Create a System object using the menu option New > System Object > Simulink Extension.
Name the System object PlotRamp and save the file. This name becomes the block dialog box title.
Delete the comment at the beginning of the file and replace it with the block description.
```
% Display a button to launch a plot figure.
```
This comment becomes the block parameters dialog box description, under the block title.
Select System Block > Launch Mask Editor > Preview Dialog. The block dialog box displays as you develop the System object.
Add a ramp limit by selecting Insert Property > Numeric. Then change the property name and set the value to 10.
```
  properties (Nontunable)
    RampLimit = 10;
  end
```

Locate the getPropertyGrouplsImpl method using the Analyze button.

      function group = getPropertyGroupsImpl
          % Define property section(s) for System block dialog
          group = matlab.system.display.Section(mfilename('class'));
      end

Create the group for the Visualize action.

      function group = getPropertyGroupsImpl
          % Define property section(s) for System block dialog
          group = matlab.system.display.Section(mfilename('class'));
          group.Actions = matlab.system.display.Action(@(~,obj)...
            visualize(obj),'Label','Visualize');
      end

Add a function that adds code to display the Visualize button on the dialog box.

  methods
    function visualize(obj)
      figure;
      d = 1:obj.RampLimit;
      plot(d);
    end
  end

As you add elements to the System block definition, save your file. Observe the effects of your code additions to the System block definition.
The System Block menu also displays checks next to the methods included in your file.

Delete any unused methods in the template or modify the methods to further customize the System object and System block. The class definition file now has all the code necessary for the PlotRamp System object.

classdef PlotRamp < matlab.System
  % Display a button to launch a plot figure.
        
  properties (Nontunable)
    RampLimit = 10;
  end
    
  methods(Static, Access=protected)
    function group = getPropertyGroupsImpl
      group = matlab.system.display.Section(mfilename('class'));
      group.Actions = matlab.system.display.Action(@(~,obj)...
            visualize(obj),'Label','Visualize');
    end
  end
    
  methods
    function visualize(obj)
      figure;
      d = 1:obj.RampLimit;
      plot(d);
    end
  end
end

After you complete your System block definition, save it, and then load it into a MATLAB System block in Simulink.