A platform-independent communication framework for the simplified development of shop-floor applications as microservice components*

For flexible and highly networked industry 4.0 production processes, software components are becoming more and more significant for reconfiguring production systems or facilitating complex functionalities. Standards for communication such as OPC UA have a crucial role in the data exchange required in this context. However, these systems adopt the static properties from their domain, which have led to their success and widespread use in Industry 4.0. The most critical core difficulties with OPC UA are the definition of communication mechanisms and the data model to be used in a strictly coupled environment. Because of their central client-server architecture and missing communication patterns, these systems do not offer the necessary flexibility and platform independence to use the entire spectrum of possible software tools efficiently. Especially negatively affected is the initial effort to integrate such systems and to guarantee the scalability of the infrastructure later on. With a focus on these challenges, the message-based communication framework XSC has been developed for the shop-floor, which uses the high-performance ZeroMQ framework and the data format Google Protocol Buffers for platform independence and a high degree of efficiency. It has a scalable and distributed multi-agent architecture that provides a distributed registry for the usage and provision of microservice components. Besides, multiple communication patterns were provided to meet the requirements of both environments, shop-floor, and cloud computing applications.