This part of IEC 62541 defines the Information Model of the OPC Unified Architecture. The Information Model describes standardised Nodes of a Server’s AddressSpace. These Nodes are standardised types as well as standardised instances used for diagnostics or as entry points to server-specific Nodes. Thus, the Information Model defines the AddressSpace of an empty OPC UAServer. However, it is not expected that all Servers will provide all of these Nodes.