IEC PAS 62406:2005

specifies the protocol set necessary for RTE-TCnet, specifically of the Data Link layer and the Application layer, which is mapped on top of the Data Link layer to exploit the services in terms of the "three-layer" Fieldbus Reference Model which is based in part on the OSI Basic Reference Model. Both Reference Models subdivide the area of standardization for interconnection into a series of layers of specification, each of manageable size