SERCOS

Scope / Goals

Develop specifications to map Sercos services and objects (IDNs) to OPC UA. Sercos devices are controls, drives, I/Os and other decentralized peripheral, such as encoders, safety devices and vision systems.
ADVANTAGES

The specified Sercos OPC UA mapping allows the access to the device information model, based on the defined Sercos profiles. Sercos device suppliers & users find ready-to-use methods, tools and applications to make available machine and process data to higher-level systems. On the other hand, manufacturers of IT systems (including MES/ ERP and SCADA software) are able to directly access the available information without the need for vendor-specific interpretations or conversions. The best of both worlds combination shows a migration to Industry 4.0, allowing to connect each and every existing Sercos-based device, with very low efforts!

Technical content

The specified OPC UA mapping for Sercos is based on an extension of an OPC UA server. Therefore, it can be used for different implementation approaches (see figure).

1. The OPC UA server functionality can be implemented in a Sercos master device (e.g. CNC or PLC). This device is acting as a gateway to map the OPC UA accesses to Sercos services and vice versa (Option a). Access to the Sercos parameters in a Sercos slave device is provided by cyclic and acyclic services of the Sercos real-time channel, or by means of the S/IP protocol which provides IP-based access to all Sercos parameters even the Sercos real-time communication is not enabled (Option 2a).
2. The OPC UA server functionality can also be implemented in a Sercos slave device. In this case, the OPC UA protocol is transmitted in the so-called Unified Communication (UC) channel of Sercos which is available in parallel to the Sercos real-time communication (option 2b) and even in the case that the Sercos real-time communication is not enabled (option 2c).

The Sercos OPC UA companion specification describes the mapping of data types between OPC UA and Sercos, as well as the transformation of the Sercos data model (consisting of profiles, classes, function groups and the supported parameters) into the OPC UA information model. By this, standardized access to the information of a Sercos field device is given

More Information

• See here: Video “Sercos and OPC UA” by Peter Lutz, Managing Director Sercos International
• Download here: Flyer : “Machine communication – Integrated networking with Sercos and OPC UA”