Allen-Bradley 1756-EN4TR EtherNet/IP Interface Module

The Allen-Bradley 1756-EN4TR EtherNet/IP Interface Module is a two-port ControlLogix communication card that provides high-speed Ethernet/IP connectivity from the chassis backplane to plant networks. Its two copper RJ-45 ports support 10/100/1000 Mbps Ethernet, enabling scalable, deterministic data exchange between a ControlLogix controller and EtherNet/IP devices such as HMIs, SCADA systems, drives, and distributed I/O. The module supports up to 512 TCP connections and 256 axes, allowing many concurrent CIP sessions for real-time I/O, configuration, and monitoring traffic. With firmware that supports PRP (Parallel Redundancy Protocol) starting around version 4.001, EN4TR can be deployed in redundant network topologies to improve availability. Designed for use in 1756 ControlLogix backplanes, the EN4TR extends Ethernet/IP communications beyond the processor, helping to isolate control-plane traffic from enterprise networks while maintaining deterministic control performance. Typical applications include plant-floor data exchange, machine-to-machine networking, and remote I/O access over a gigabit Ethernet fabric.