External components, External component screen, External substances, Practical use, Using an external process, Default instanciation, Selection of the class, Instantiation of the class choosen, Configuration of Thermoptim , Loading extUser.zip with Winzip, Basic concepts, Programming with Java, Compilation of a class, Classes grouped in packages, External class archives, External class viewer, Thermocouplers, Thermocoupler screen, Java environnement, Two modes of operation, Thermoptim emulation, Structure of the external class mechanism, SolarCollector class, Calculations, Backup / reading of parameters, External nodes , Consistency check