Establishing communication

To establish the connection:

1. Define the data point elements that are to be read, and assign to the data point group OPCRead.

2. Define the data point elements that are to be written to, and assign to the data point group OPCWrite. Values can be set later for these.

3. Start the server in the console after starting the Data and Event Managers. The Server was registered automatically at installation.

4. Start the client

5. Set up the connection to the OPC server as specified in the client handbook. The ProgID (Program Identification from the registry) of the OPC Server is "WinCC_OA.OPC.1" - Generate groups and items on the client.

Automatic general query at the driver start or redundancy switch

The OPC driver receives all data from the server when starting. Thus, a general query is not necessary. The OPC driver, however, executes a general query at a redundancy switch.

In theory the client could also start the server. Starting from the console, however, ensures that the server is also closed when WinCC OA is shut down, so this is advised.