Allen-Bradley 1756-EN2TR ControlLogix Ethernet Module

The Allen-Bradley 1756-EN2TR is a dual-port EtherNet/IP communication module for the ControlLogix platform, adding two 10/100 Mbps Ethernet interfaces to a CLX chassis for simultaneous connections to multiple networks or devices. It supports device‑level ring (DLR) hardware redundancy for fast network failover and handles up to 128 TCP connections plus 256 CIP connections to support both implicit I/O data and explicit messaging. Firmware version 10.007 and catalog number 1756-EN2TR (part number 184724) are specified with this module. It includes USB ports for local configuration and USB-to-Ethernet/USB-to-backplane bridging on compatible series, with Ethernet isolated from the backplane at 30 V continuous. Typical uses include real‑time I/O messaging, PLC-to-PLC data exchange, and integrating a ControlLogix controller with enterprise networks via EtherNet/IP; the EN2TR plugs into a 1756 backplane and remains a 10/100 module (not Gigabit).