1756-EN2TR Rockwell Automation ControlLogix High-Capacity Ethernet Interface

Brief Product Description

The Allen-Bradley 1756-EN2TR provides high-performance, multi-protocol communication for ControlLogix chassis, enabling seamless integration of real-time I/O, motion control, and safety data across industrial networks.

Product Overview

The 1756-EN2TR functions as a high-performance communication gateway within the Rockwell Automation Integrated Architecture. This module facilitates high-speed data exchange between ControlLogix controllers and various field devices, including remote I/O, variable frequency drives, and other PLC platforms. By incorporating dual RJ45 ports, the unit supports versatile network architectures such as linear, star, and high-availability Device Level Ring (DLR) topologies. Furthermore, the module implements CIP Safety protocols, which allows engineers to converge standard control and safety traffic onto a single, unified network cable. Consequently, this integration reduces wiring complexity and minimizes potential points of failure in safety-critical industrial applications.

Technical Specifications

• Brand: Allen-Bradley / Rockwell Automation
• Model Number: 1756-EN2TR
• Communication Protocol: EtherNet/IP
• Connection Capacity: 256 CIP connections; 128 TCP/IP sessions
• Data Rate: 10/100 Mbps (Auto-sensing)
• Network Topologies: Device Level Ring (DLR), Linear, Star
• Packet Rate: 10,000 packets per second (I/O)
• Backplane Current: 1.0 A @ 5.1V DC
• Power Dissipation: 5.1 W
• Slot Requirement: Any single slot in 1756 Chassis
• Environmental Rating: Operating temperature 0 to 60 °C (32 to 140 °F)
• Weight: 0.9 kg

Functional Characteristics

The 1756-EN2TR utilizes an advanced internal architecture to prioritize deterministic data delivery, which is essential for multi-axis integrated motion applications. Since the module supports 128 TCP/IP sessions, it easily manages high-volume messaging from HMI terminals and SCADA software without compromising real-time I/O performance. Additionally, the bridge functionality allows for seamless routing of messages across different networks without the need for complex scheduling or specialized programming.

Installation requires no specific slot assignment, granting system designers maximum flexibility when configuring local or remote ControlLogix chassis. To streamline the setup phase, the module supports standard BOOTP/DHCP tools for IP address assignment and provides diagnostic LEDs to monitor link status and network activity instantly. Moreover, the hardware maintains absolute interoperability with Flex I/O, Point I/O, and third-party EtherNet/IP enabled devices, ensuring a cohesive automation ecosystem.

Engineering Advantages

The primary advantage of the 1756-EN2TR lies in its internal DLR technology, which provides a resilient network path. If a physical break occurs in the network ring, the module automatically reroutes traffic to prevent system downtime. Therefore, it serves as a critical component for 24/7 manufacturing operations. Furthermore, because the module handles high-capacity CIP traffic, it effectively supports complex modular machines that require extensive data synchronization. This deterministic capability ensures that motion axes remain perfectly aligned across distributed nodes, regardless of network traffic fluctuations.