As a link between production and ERP (see Figure 1), an MES requires communication interfaces to the subordinate machines and the higher-level ERP. The communication with the ERP is usually done via standard mechanisms such as SQL or XML, while the connection down to the machines and process control systems is often complex and expensive. There are many different communication standards in automation systems, and the availability of data relevant to the MES varies greatly from machine to machine, requiring complex engineering to connect these different systems.

To meet the challenge of different communication standards in automation systems, the Weihenstephan Standards defines two universal communication interfaces for connecting different machine and process control systems to an MES:

• WS Protocol
• WS OPC UA

With “WS-Protocol - Physical Interface Specifications”, a specified WS communication interface for data exchange between higher-level IT systems was developed in 2005. It is based on Ethernet TCP/IP and provides proprietary communication commands that allow easy implementation independent of hardware, software and platform. For further information please refer to https://www.weihenstephan-standards.com/.

The present document CS OPC UA for Weihenstephan Standards now provides a second opportunity to ensure that the Weihenstephan Standards meets the requirements for communication in an Industry 4.0 environment.