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