9 Profiles and namespaces

9.1 Namespace metadata

Table 50 defines the namespace metadata for this specification. The Object is used to provide version information for the namespace and an indication about static Nodes. Static Nodes are identical for all Attributes in all Servers, including the Value Attribute. See OPC 10000-5 for more details.

The information is provided as Object of type NamespaceMetadataType. This Object is a component of the Namespaces Object that is part of the Server Object. The NamespaceMetadataType ObjectType and its Properties are defined in OPC 10000-5.

The version information is also provided as part of the ModelTableEntry in the UANodeSet XML file. The UANodeSet XML schema is defined in OPC 10000-6.

9.2 OPC UA Conformance Units and Profiles

This chapter defines the corresponding profiles and conformance units for the OPC UA Information Model for POWERLINK Profiles are named groupings of conformance units. Facets are profiles that will be combined with other Profiles to define the complete functionality of an OPC UA Server or Client. The following tables specify the facets available for Servers that implement the POWERLINK Information Model companion standard, and for Clients that are communicating with such Servers.

Table 51 defines a server facet for direct access to the POWERLINK Objects through a structured NodeId that may be generated by user entry or by tools.

Table 52 defines a client facet for direct access to the POWERLINK Objects through a structured NodeId that may be generated by user entry or by tools.

Table 53 defines a server facet for access to POWERLINK Objects of the communication profiles EPSG DS 301 and EPSG DS302 through the OPC UA Information Model.

Table 54 defines a client facet for access to POWERLINK Objects of the communication profiles EPSG DS 301 and EPSG DS302 through the OPC UA Information Model.

9.3 Handling of OPC UA namespaces

Namespaces are used by OPC UA to create unique identifiers across different naming authorities. The Attributes NodeId and BrowseName are identifiers. A node in the UA Address Space is unambiguously identified using a NodeId. Unlike NodeIds, the BrowseName cannot be used to unambiguously identify a node. Different nodes may have the same BrowseName. They are used to build a browse path between two nodes or to define a standard Property.

Servers may often choose to use the same namespace for the NodeId and the BrowseName. However, if they want to provide a standard Property, its BrowseName shall have the namespace of the standards body although the namespace of the NodeId reflects something else, for example the EngineeringUnits property. All NodeIds of nodes not defined in this specification shall not use the standard namespaces.

Table 55 provides a list of mandatory and optional namespaces used in a POWERLINK OPC UA Server.

Table 56 provides a list of namespaces and their index used for BrowseNames in this specification. The default namespace of this specification is not listed since all BrowseNames without prefix use this default namespace.