Internal datapoints of the OPC UA server

The WinCC OA OPC UA server uses a central datapoint of the type _OPCUAPvssServer for general status displays and configuration parameters. By default, this datapoint is named OPCUAPvssServer. The manager number is not included in the name, as typically only one OPC UA server is present in a project, and it can be started with any manager number. You can set the datapoint name in the config configuration file (see Possible Config Entries for the OPC UA Server).

_OPCUAPvssServer

Datapoint element Type Description
Config.EnableLogging uint

Enables logging in the OPC UA SDK (UaTrace).

No logging = 0 (default)
Config.DisableDataUpdate uint

If set to 1, no data values are updated in the OPC UA process space. If values change in the WinCC OA project, the value is marked as "Uncertain" in the OPC UA process space.

If this element is reset to 0, current values are sent to the client automatically, without any client action.

Default value = 0
Config.DisableWrite uint
  • If set to 1, the UA server does not allow write requests from clients and returns the error code WriteNotAllowed.
  • If set to 2, write requests are silently discarded without any error on the client side.
Config.CNSViews dyn_string This element contains all CNS views linked to the server for creating the address space.
Config.GroupAuthentication dyn_uint Group authentication can be enabled with this element. By default, this element is empty, so group authentication is not active. If you define group IDs, the server checks whether the specified user is a member of at least one of the defined groups, in addition to user authentication.
Config.AlarmPrioMapping dyn_string

This element contains all configured assignments of WinCC OA alert classes to OPC UA severities.

When the OPC UA server receives an alert from WinCC OA, it checks for configured severities. If a severity is set for the alert class, the alert is forwarded using it. Otherwise, the WinCC OA alert priority is used as the OPC UA severity.

The list contains one entry for each assignment in the format <alert_class> <severity>.
Config.StatusMapping dyn_string

This element contains all configured assignments of user bits to OPC UA status codes.

When the value of the server datapoint element changes, it checks for mapped user bits. If a user bit with an assigned status code is set, the server forwards the value change with that status code. If multiple user bits with assigned status codes are set, the highest one is used.

The list contains one entry for each assignment in the format <user_bit> <status_code>.
Config.DatapointLogging bit32

This element enables or disables datapoint logging.

Session Logging
Set bit 1 to TRUE to enable Session Logging. This logs whenever a client connects or disconnects, and writes to State.DatapointLogging.Session.
Write Logging
Set bit 2 to TRUE to enable Write Logging. This logs all value changes made by clients, and writes to State.DatapointLogging.Write.
Method Logging
Set bit 3 to TRUE to enable Method Logging. This logs method calls, including the Session ID and Node ID, and writes to State.DatapointLogging.Method.
Important:
Bit numbering starts at 1.
Tip:
You can combine multiple bits as needed.
Command.DebugPI bool Returns the current datapoint elements enabled by the OPC UA server and their UaNodeIds to the log file.
  • 0 -> no action
  • 1 -> output is generated
Note:
The debug flag "-dbg 10" is required for the OPC UA server; otherwise, no information is written to the log files.
State.ClientsConnected uint Number of clients currently connected to the OPC UA server.
State.CNSViews dyn_int

Shows the current state of each CNS view.

Status Description
0 The CNS view state is not defined because the OPC server is not running. If the server was not stopped properly (for example, using the KILL command), the last set status remains until the OPC server is started again.
1 The distributed system is connected, and the CNS view (or all OPC elements of the view) are correctly present in the server's address space. The values of all elements in the address space match the actual value of the respective data point element.
2 The distributed system is connected, and a delta synchronization is running. Connected OPC clients can receive values from the OPC server.
3 The distributed system is connected, and the entire CNS view is being refreshed in the OPC server's address space (Full Sync). In this case, connected OPC clients receive the last usable values from the OPC server, which are marked with OPC quality "Uncertain, Last Usable Value". If one CNS view of a system is in Full Sync state, all other CNS views will also be in this state.
4 The distributed system is connected, but the configured CNS view does not exist or cannot be found in the system.
5 The distributed system is not connected, and the server does not have any information about the configured CNS views in the address space. As soon as the distributed system is connected, the OPC server performs a full synchronization for all views.
6

The distributed system is not connected, but the OPC server has IP identification and CNS views in its address space. The server marks all values of the CNS view system with OPC quality status "Uncertain, Last Usable Value". If the connection to the distributed system is established, the OPC server starts a full or delta synchronization, depending on the maxUpdateMsgCount config entry and the amount of changed data.

If the OPC server is started with useLocalIdentification, the address space is created using information loaded from proj_path/data/DpMsgTypeContainer.bin and proj_path/data/DpMsgIdentification.bin, so TypeContainer and DpIdentification do not need to be transmitted over the network.
State.MaxNumberOfClients bool

Indicates whether the maximum number of client connections has been reached.

TRUE = maximum number reached

FALSE = maximum number not reached
State.DatapointLogging.Session string

This element is updated whenever a client connects or disconnects from the server.

It contains messages in the format:

<hex session id> <code> “<session name>” “<authentication method>” “<username>” <hex ua status code>

For more information, see Enable Session Logging.

This element is only updated when Session Logging is enabled in Config.DatapointLogging.
State.DatapointLogging.Write string

This element is updated whenever an OPC UA client changes values.

It contains messages in the format:

<hex session id> <UA node id> <new value> <hex ua status code>

For more information, see Enable Write Logging.

This element is only updated when Write Logging is enabled in Config.DatapointLogging.
State.DatapointLogging.Method string

This element is updated whenever an OPC UA Method is called.

It contains messages in the format:

<hex session id> <UA node id>

For more information, see Enable Method Logging.

This element is only updated when Method Logging is enabled in Config.DatapointLogging.