OPC is the technological basis for the convenient and efficient link of automation components with control hardware. The topic covered during our diploma thesis was: ?Receive time consistent data with an OPC XML-DA Server? An OPC XML-DA Server allows access to data from a PLC over the Internet. All that is needed is a network connection between the OPC XML-DA Server and the OPC XML Client. So it is possible for an employee to supervise an automation component over an OPC XML-DA Server.

The purpose of this research project is to develop an add-on for an existing OPC-XML-Server running on an industrial PC. This add-on enables to directly connect a PLC ControlLogix 5563 to receive process data. The process data has to be consistent in time.

Our Software is written in C# and includes the .NET Framework from Microsoft as well as the OPC .NET API from the OPC Foundation. To access the ControlLogix PLC over the backplane a C-DLL API from OLDI is used. Our task was to establish communication between the OPC Server and the C-DLL API.

As the result an OPC XML Client is able to connect to our OPC XML Server and select some data points to a group which can be observed.

This software has been tested in various situations. The resulting software is working properly. For a professional use of this software only a few additional functions are necessary.