A CoAP-based OPC UA Transmission Scheme for Resource-Constrained Devices

The Industrial Internet continuously covers all aspects of smart manufacturing. As an enabling technology for Industrial Internet, OPC UA protocol realizes the information modeling and unified description of industry devices. Furthermore, OPC UA supports data access through Web services based on HTTP. However, the high resource cost of HTTP for resource-constrained devices is hard to afford. The CoAP protocol is specially designed for resource-constrained devices, and it has better suitability in the IoT environment than HTTP. Therefore, an efficient and lightweight transmission scheme, which is applied to realize the transfer of OPC UA messages over the CoAP protocol, is proposed in this paper. Experimental results demonstrate that the proposed scheme realizes the effective transmission of resource-constrained device data through the Web service interface via OPC UA.