Abstract: This paper proposes and analyzes a real-time Ethernet (REPC) communication model for process control, based on switched Ethernet and IEEE 802.1Q/P technologies. Keywords: Communication Model; Industrial Ethernet; Process Control Currently, process control system technologies are gradually converging with computer standards and network specifications, with Foundation Fieldbus FF H1 and Profibus PA being typical examples of widely used technologies. Meanwhile, Ethernet technology is developing rapidly, not only being widely applied in the industrial control and monitoring layer, but also, as key technologies for Ethernet adaptation to industrial environments are continuously being broken through, its application to control field devices will become an inevitable trend. This paper proposes and analyzes a real-time Ethernet (REPC) communication model for small and medium-sized process control environments. 1. REPC Communication Model Structure Analysis Real-time Ethernet models, including the EPA proposed by Zhejiang University in China, generally utilize a hub, disable CSMA/CD access through a higher-level protocol layer, and replace it with time-slicing or polling processes. Unlike these models, the REPC model is built on switched Ethernet and IEEE 802.1Q/P technology, making its implementation simpler. For details, please click: Discussion on Ethernet Communication Models in Process Control Industry