Siemens SIMATIC ET 200AL System Manual page 1446

Alternative:
You can also select a new read list by dragging the right field of the editor ("OPC UA Server
interface") to a node of the type Object or Folder and then dragging it to "Add new read
list" in the left field of the editor. The new read list then contains all PLC tags of the node
that has been moved.
In the example, select the object "Data_for_OPC_UA_Clients", which contains the tags
"NewProduct" and "ProductNumber". STEP 7 generates the new read list
"Data_for_OPC_UA_Clients". In addition, the object contains the tag "Temperature". Delete
the "Temperature" tag from the read list. Since they should not be read in the example.
Change the name of the read list in "ReadListProduct".
The following figure shows the content of the read list:
Figure 9-64
Note
Read and write lists do not support all node types.
The OPC UA client of the S7-1500 CPU does not support all OPC UA data types (node
types) that can be made available via an OPC UA server interface. If you place an
unsupported node type, for example, in a read list or write list a corresponding error signal
appears. In this case, you cannot include the corresponding node in the read or write list.
Which types are supported is described here: Mapping of data types (Page 169)
Communication
Function Manual, 05/2021, A5E03735815-AJ
Read list
9.4 Using the S7-1500 CPU as an OPC UA client
OPC UA communication
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