This part of IEC 62541 defines the Information Model of the OPC Unified Architecture (OPC UA). 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 UA server. However, it is not expected that all servers will provide all of these Nodes.