Setup of the Communication between OPC UA Client and Server

In order to setup functioning communication between the WinCC OA OPC UA client and WinCC OA OPC UA server the steps described in the following are necessary. Detailed explanations can be found in the further chapters. It is assumed that WinCC OA is already installed.

1. Creating data points

Per used server an internal connection data point of the type _OPCUAServer has to exist and per used subscription an internal data point of the type _OPCUASubscription has to exist (see also internal data points of the OPC UA client). These are created and configured in the corresponding panels (see configuration of the servers and configuration of a subscription).

2. Startup of the client

The WinCC OA OPC UA client has to be started like each other WinCC OA manager:

Insert the OPC UA client manager (WCCOAopcua) to be started in the WinCC OA console. For the OPC UA client all WinCC OA standard command line options can be used, as the client does not have own ones. In case that several managers are running each manager (=driver) must be started with another manager number. The manager number is specified by the -num <manager number> option. The use of the further parameters are described in the corresponding documentation chapters.

Note

When the WinCC OA OPC UA manager is running, then the simulation driver must be stopped.

3. Set internal data points

A server can be added dynamically to a WinCC OA project without a restart of the OPC UA client. Therefore the name of the OPC UA data point (see step 1.) must be written to the "_OPCUA<manager number>.Command.AddServer DPE. In order to establish a connection between an OPC UA data point and the manager successfully, the OPC UA data point must be already created with the corresponding number of the manager. A connection will be then established as long as the client is active and running. If the client stops, the connection is severed and will not reestablish automatically after the restart of the client. To set the connection persistent, the OPC UA data point must be added to the "_OPCUA<manager number>.Config.Servers". If a peripheral address has already been created for the server, this step is not necessary anymore due to being added automatically to the DPE "_OPCUA<manager number>.Config.Servers".

4. Connection setup on the WinCC OA OPC UA server (in WinCC OA project)

Assignment of data point elements to the data point groups OPCUARead (data that can only be read over OPC UA) and OPCUAWrite (data that can be read and written over OPC UA).

For further information see Access to WinCC OA data.

5. Startup of the server

In order that an OPC UA client can communicate over the WinCC OA OPC UA server with WinCC OA, the OPC UA server manager (WCCOAopcuasrv) has to be added to the WinCC OA console of the project. This establishes the communication with the Event Manager.

Start the WinCC OA OPC UA server manager.

Note

In the event that the WinCC OA OPC UA server manager cannot be started and an error message is displayed in the WinCC OA log viewer, the reason for that could be:

- The server port number is occupied (in order to change it see possible config entries for the OPC UA client)
- The certificate directory cannot be found (for information on certificates see certificates)

6. Definition of the peripheral addresses in the WinCC OA client project

Via the peripheral address the assignment of hardware address in the target system to the address of the WinCC OA data point element takes place. See Definition of the peripheral address of the OPC UA driver.

7. Browsing for items in the WinCC OA client project

Browsing for items in the server address space - see Browsing for Items.