2.1 IO control systems2.1.1 General IO system description2.1.2 Input-output (IO) description of a plant2.1.3 Input-output (IO) description of a feedback controller2.1.4 Input-output (IO) description of a feedback control system2.2 ISO control systems2.2.1 General ISO system2.2.2 ISO plant2.2.3 ISO feedback controller2.2.4 ISO feedback control system