These classes follow the polymorphic structure as implemented in ECLASS Advanced. All these classes, including CNS_CP|4|3, have a set of common attributes so that they are in principle interchangeable and can be used in a common schema. In particular, the procedures described above apply without restriction.

The system supports the other connection types (individual connections) defined under ECLASS "CAx connection and function":

With certain restrictions, the CNS_CP|4|9 plug connections are also included in this list. However, this depends on the type of engineering and will be worked out in detail in a separate chapter. The decisive attributes that enable the basic modeling of all these connection types are given by

In analogy to the individual electrical connections, the second pin of the symbol shown is indexed via the Connection EclassSymbolMap attribute and integrated into the function structure. If the given part is not described by other functions/symbols, this attribute assumes the following values for the 3 class instances CNS_CP|4|9:

This procedure couples the real/physical hydraulic connection with the (logical) symbol or function connection in complete analogy to electrical connections.