Digital Twin in Automation Industry: Optimal Communication Protocol

Digital Twin Technology (DTT) creates a digital copy of a physical object or system, allowing interaction and control between physical and digital counterparts. Effective communication between the digital and physical entities is crucial for real-time interactions. This study explored the performance of three common communication protocols, MQTT, HTTP, and WebSocket, in a Digital Twin setup involving a Programmable Logic Controller (PLC) included PLCnext technology, an IoT platform called Thingsboard, and a 3D Game Engine called Unity. The focus is on measuring the delay or latency in data transmission and retrieval using those mentioned protocols. The data transmission latency was measured during data uploading to and data retrieval from the IoT platform. The results show that the MQTT protocol is faster than the HTTP protocol in sending data to Thingsboard platform due to its simpler and lighter design. Additionally, the WebSocket protocol shows a slight advantage over HTTP in retrieving data from the Thingsboard platform to Unity, which is important for real-time interactions in the Digital Twin setup. The findings from this study serve as crucial information for choosing the right communication protocols in Digital Twin setups for the Industry 4.0 to improve real-time interactions in automation industry.