Add a first figure to Modelica.Blocks.Examples.PID_Controller

Modelica/Blocks/package.mo

@@ -155,7 +155,10 @@ works reasonably, since the input to the limiter (PI.limiter.u)
 is forced back to its limit after a transient phase.
 </p>
 
-</html>"));
+</html>", figures = {Figure(title = "Anti-windup compensation", identifier = "anti-windup", preferred = true, plots = {Plot(title = "Reference tracking", identifier = "tracking", curves = {Curve(y = integrator.y, legend = "Reference speed"), Curve(y = inertia1.w, legend = "Actual speed")}), Plot(title = "Anti-windup limiter", identifier = "limiter", curves = {Curve(y = PI.limiter.u, legend = "Input to the anti-windup limiter"), Curve(y = PI.y, legend = "Controller output")})}, caption = "%(plot:tracking) Reference speed (%(variable:integrator.y)) and the actual speed (%(variable:inertia1.w)). The system initializes in steady state, since no transients are present. The inertia follows the reference speed quite good until the end of the constant speed phase. Then there is a deviation.
+
+%(plot:limiter) Here the reason for the deviation can be seen: The output of the controller (%(variable:PI.y)) is in its limits. The anti-windup compensation works reasonably, since the input to the limiter (%(variable:PI.limiter.u)) is forced back to its limit after a transient phase.
+")}));
   end PID_Controller;
 
   model Filter "Demonstrates the Continuous.Filter block with various options"