OPC
WinCC OA allows to map a CNS view to the address space of OPC servers. Therefore the server address space is independent from the data point structure of the respective project and can be freely defined (see also OPC DA server CNS, OPC HDA server CNS and OPC UA server CNS for further information).
Figure - OPC
After creating a view, the appropriate element can be selected via the tree on the left side.
OPC Access Right
The bits corresponding to the set checkboxes define the AccessLevel of the node and are automatically written on the UserData with the key "OA:OPC" (refer to the CNS chapter of the respective OPC server for further information on the AccessLevel). You can also use the CTRL function cnsSetProperty to define the AccessLevel.
Inheritance
These options define which nodes are mapped to the address space and how the values of nodes can be accessed.
- Inherit from parent node - Settings are inherited from the parent node
- Apply only for this node - Settings are only applied for this node
- Apply for this node and subnodes - Settings are applied for this node as well as child nodes
Read
Defines if the node value is readable.
Write
Defines if the node value is writable.
History
Defines if the history of a value is readable.
Alarms
Defines if the alert information is represented in the address space.
Event
Defines if the data point element of the node can send an OPC UA Base Event. This is only supported for dyn_string DPEs.
- Index 0 - Severity; Value Range: [1,1000]
- Index 1 - Event text; Custom string
