The specification describes the combination of AutomationML with OPC UA online information like process data and diagnostic information. It extends the application domain of OPC UA (see Figure 6). Therefore, different use cases which will be possible by the combination of both standards were identified.


Figure 6 – Goals of AutomationML and OPC UA

One opportunity from combining AutomationML and OPC UA is to communicate and operationalise AutomationML by means of OPC UA. It is possible to simplify the creation of OPC UA information models based on existing AutomationML data. This can be realized by a so called OPC UA companion specification due to analogies between AutomationML and the OPC UA information model. The companion specification for AutomationML consists of an object model including many specific semantics which can be used online with multiple involved parties by OPC UA. This makes an online version of the AutomationML model possible - AutomationML models can be exchanged via OPC UA – and includes OPC UA data management, online communication functionality, multi-user support, access methods, security, etc. This is especially important for re-engineering and maintenance use cases where the AutomationML model evolves over time. The present AutomationML model can be managed by OPC UA and makes an up-to-date description of the system as-is possible.

One other opportunity is the lossless exchange of the OPC UA system configuration within AutomationML models. The manual exchange of OPC UA server configuration data will be replaced by a specified description in AutomationML. Parameters to set up OPC UA communication between tools can be exchanged using AutomationML. This realizes consistent data, produces less errors and results in an easier and faster configuration of UA servers and clients. OPC UA can benefit from the description of the complete communication network configuration and structure including communication components of sensors and actuators with respect to communication system parameters, network structure and wiring, quality of service.