The ABB EI802F with part number 3BDH000016R1 is a legacy rack-mounted Ethernet interface module exclusively developed for the ABB Freelance AC 800F distributed control system, serving as a core wired communication gateway for early-generation DCS networking. Unlike RJ45-based EI811F, this module adopts a standard AUI coaxial interface compliant with IEEE 802.3 Ethernet standards, supporting thick coaxial cable network access for legacy on-site wiring. It draws stable power directly from the AC 800F rack backplane with no external power supply required, cutting extra circuit layout and reducing potential loose wiring faults in vibrating industrial cabinets. Two built-in LED indicators separately show power operation status and real-time Ethernet data transmission, allowing field technicians to locate network interruption, frame loss and link failure without dedicated Freelance configuration software. With full metal shielding housing, it meets IEC 61000-6-2 industrial EMC standards, resisting electromagnetic interference from nearby variable frequency drives and high-voltage power equipment. Its rated operating temperature ranges from 0°C to 55°C, while storage temperature covers -20°C to 70°C, adapting to humid, dusty working conditions in power plants, traditional chemical plants and water treatment stations with reserved coaxial network infrastructure. It supports controlled hot swapping under non-critical system load to avoid full-system shutdown during module replacement. Fully compatible with Freelance Control Builder, it features automatic hardware scanning and one-click protocol matching. Manufactured in Sweden, each module passes strict ESD and surge testing before delivery, and is covered by a 12-month official manufacturer warranty for long-term 24/7 industrial operation.