examples/org.eclipse.epsilon.emc.simulink.examples/create/createFeedbackController.eol

var reference = new `simulink/Sources/Step`;
var controller = new `simulink/Ports & Subsystems/Subsystem`;
var plant = new `simulink/Ports & Subsystems/Subsystem`;
var sum = new `simulink/Math Operations/Sum`;

reference.name = "Reference";
controller.name = "Controller";
plant.name = "Plant";

// Position them on the diagram
reference.position = "[100 100 130 130]";
sum.position = "[200 100 230 130]";
controller.position = "[300 100 400 130]";
plant.position = "[500 100 600 130]";

// Controller subsystem
var pidController = new `simulink/Continuous/PID Controller`;
pidController.name = "PID Controller";
pidController.parent = controller;

var error = Inport.all.selectOne(ip|ip.parent = controller and ip.name="In1");
error.name = "Error";
var control = Outport.all.selectOne(op|op.parent = controller and op.name="Out1");
control.name = "Control";
error.unlink(control);
error.link(pidController);
pidController.link(control);

// Plant subsystem
var transferFcn = new `simulink/Continuous/Transfer Fcn`;
transferFcn.parent = plant;
// to be continued

reference.link(sum);
sum.link(controller);
controller.link(plant);
plant.linkTo(sum, 2);