Allen-Bradley 1761-NET-ENI Ethernet Interface Module

The Allen-Bradley 1761-NET-ENI Ethernet Interface Module is the original Rockwell Ethernet bridge for legacy SLC 500 DH-485 systems, providing Ethernet connectivity for SLC 5/03 PLCs that natively communicate over DH-485. It lets an Ethernet network reach the SLC 5/03 serial network, enabling integration with modern IP‑based tooling and PC software that expect Ethernet access. The ENI is a Rockwell/Allen‑Bradley device designed to connect DH‑485 based controllers on the SLC/MicroLogix family to an Ethernet network, effectively bridging legacy serial communication to Ethernet. In Rockwell’s product lifecycle, the 1761-NET-ENI was discontinued on January 31, 2017, with guidance that customers consider replacement options from third‑party vendors offering ENI‑compatible solutions. Configuration typically involves IP addressing via an ENI setup workflow, with documentation noting that the ENI/ENIW does not have a fixed address until configured, and examples reference an addressing string that includes 192.168.1.254 as part of the setup. For customers seeking a modern substitute, Real Time Automation’s 515RTAENI and other third‑party ENI replacements provide similar Ethernet‑to‑DF1/DH‑485 bridging capabilities to keep legacy networks connected on current hardware.