Siemens SIMATIC S7-1500 Function Manual page 161

OPC UA communication
9.3 Using the S7-1500 as an OPC UA server
Node classes
OPC UA servers provide information in the form of nodes. A node can be, for example, an
object, a tag, a method or a property.
The example below shows the address space of the OPC UA server of an S7-1500 CPU
(extract from the OPC UA client "UaExpert" from Unified Automation).
Figure 9-7
In the figure above, the "MyValue" tag is selected (highlighted in gray).
This tag is located below the "Memory" node, which has the node class "Object".
"Memory" is below the "PLC_1" node (also an Object).
Address space
The nodes are linked over references, for example, the reference "HasComponent, which
represents a hierarchical relationship between a node and its subordinate nodes. With their
references, the nodes form a network that can, for example, take the form of a tree.
A network of nodes is also called an address space. Starting from the root, all nodes can be
reached in the address space.
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Example of the address space of the OPC UA server of an S7-1500 CPU
Function Manual, 11/2019, A5E03735815-AH
Communication