OPC UA is a vendor-independent protocol to enable interoperability between Industrial automation systems. This protocol supports a range of transport layer protocols, including TCP, UDP, HTTPS, MQTT and AMQP enabling it to transfer the data from the field-level devices to the enterprise-level applications running in the cloud. However, it does not fulfill all the requirements for time-critical systems. To address this, OPC UA can be integrated with TSN as a set of IEEE standards for low-latency communication for real-time applications over Ethernet.

In this funded research project, we have been working on the the requirements, preconditions, and the architecture for a low-footprint OPC UA + TSN SDK which features a gPTP stack, LLDP, RTOS, TCP/IP stack, security, OPC UA Stack & configuration modules which are hardware and OS independent. The design can be well optimized to have sufficient memory and processor cycles to ensure smooth execution of the user application at sub-millisecond network cycle times on low-memory footprint processors. This SDK is prepared to be integrated with wired as well as wireless (Wi-Fi, 5G) TSN networks by using a clean abstraction layer to adapt the physical layers. The test suite developed as part of the SDK provides a low-cost testing ecosystem for time sync, traffic scheduling and network jitter.

This SDK provides machine builders with the base layer technology while allowing them to concentrate on their expertise and improve their business models by integrating OPC UA over TSN.