Dear Oscar,

You have an output that is negative is to get the error it is necessary to have a positive reaction.

The controllable canonical form can analyze and synthesize a control easier.

The application of the controllable canonical form perfectly represents the process and using it can synthesize any qualifying order.

Best regards

So the system image is incorrect?

I know that the output is negative , but the feedback is positive : Could get the error so ?

If the system is wrong : how you could do positive plant or the positive output ?

Thank you very much for your attention .

A greeting.

No your image is correct.

If your error is not zero you will get a ‘Epsilone’ since you have the difference between a positive setpoint and a negative output.

Good understanding 

oh , gratifies me that the system is correct.

I introduced in Simulink with a step and got the expected sign.

Thank you very much for your help!

A greeting