Addressing Of Nodes; Opc Ua Variables - Siemens PROFINET SIRIUS 3RW5 Equipment Manual

Functions
8.4 OPC UA server
8.4.7

Addressing of nodes

Nodes are the basic elements of OPC UA and are comparable with objects from object-oriented
programming. Nodes are used, for example, for user data (variables) or other metadata. Nodes
are used to model an OPC UA address space that also contains a type model with type definitions.
Node ID (NoteId)
Nodes in the OPC UA address space are unambiguously defined by a NodeId (Node Identifier).
The NodeId consists of the identifier ("identifier"), identifier type ("identifierType") and a
namespace index ("namespaceIndex"). Namespaces are used to avoid name conflicts.
The OPC Foundation has defined a number of nodes that provide information about the
respective OPC UA server. These nodes are located in the namespace of the OPC Foundation and
have the index 0. Furthermore, the OPC Foundation has defined data and variable types.
Namespace
Besides the OPC Foundation namespace described above, the namespace for accessing 3RW5
data is of interest: All variables or methods of a 3RW5 OPC UA server are located in the
namespace of the standard server interface "http://siemens.com/opcua/2020/controlproducts/
3rw55". By default, this namespace has the index 6. Another namespace with index 2 is "http://
siemens.com/opcua/2020/controlproducts/siriussimple".
Identifier
The 3RW5 OPC UA server uses numeric identifiers (IdentifierType = NUMERIC) to identify the
nodes. These numeric identifiers allow OPC UA clients to access the corresponding OPC UA
nodes (e.g. variables).
8.4.8

OPC UA variables

The 3RW5 OPC UA server supports the OPC UA specification "OPC 10000 100 ‑ Part 100: Device
Information Model". The information model contains the units for measured values and
parameters.
Faults and warnings
In addition to the individual variables for diagnostics, there is a variable for faults and warnings.
The description of the messages for faults and warnings are shown in separate tables.
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SIRIUS 3RW5 PROFINET communication modules
Equipment Manual, 05/2021, A5E35631297002A/RS-AD/004