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8.2 NodeId ToC Previous Next

8.2.3 IdType ToC Previous Next

The IdType element identifies the type of the NodeId, its format and its scope. Its values are defined in Table 23.

Table 23 – IdType Values

Value Description
NUMERIC_0 Numeric value
STRING_1 String value
GUID_2 Globally Unique Identifier
OPAQUE_3 Namespace specific format

Normally the scope of NodeIds is the Server in which they are defined. For certain types of NodeIds, NodeIds can uniquely identify a Node within a system, or across systems (e.g. GUIDs). System-wide and globally-unique identifiers allow Clients to track Nodes, such as work orders, as they move between OPC UA Servers as they progress through the system.

Opaque identifiers are identifiers that are free-format byte strings that might or might not be human interpretable.

String identifiers are case sensitive. That is, Clients shall consider them case sensitive. Servers are allowed to provide alternative NodeIds (see 5.2.2) and using this mechanism severs can handle NodeIds as case insensitive.

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