The structure of the Companion Specification Profile and its Facets is interdependent, as depicted in Figure 20. Implementations of the Companion Specification are required to fulfil the LADS BaseServer Server Profile. Additionally, up to three optional Facets - Maintenance, ProgramManager, and ExtendedFunctionalUnit (blue) - can be implemented.

The Maintenance Facet encompasses all necessary nodes for maintenance use cases. The ProgramManager Facet includes all nodes for read-only Program Management, which can be expanded with management methods in the ExtendedProgramManager.

The ExtendedFunctionalUnit Profile mandates the optional methods of the FunctionalUnit, enabling control of a functional unit and a program. This structure provides a comprehensive and flexible framework for implementing the LADS Companion Specification.

In addition, at least one Facet function (grey) needs to be implemented. For the CoverFunction and the ControllerFunction, there is a base Profile (read-only) and an extended Profile with method and write implementation.

Figure 20 – Overview of the Profiles