Allen-Bradley 1756-EN2TR Ethernet/IP Communication Module — Product Introduction

Overview

The Allen-Bradley 1756-EN2TR is a high-performance EtherNet/IP communication module designed for the ControlLogix platform by Rockwell Automation. It plays a crucial role in modern industrial automation systems, enabling reliable, high-speed communication between controllers, I/O devices, HMIs, and supervisory systems. This module is particularly valued in manufacturing plants and process control environments where seamless communication, redundant networking, and real-time data exchange are essential for operational efficiency and safety.

Unlike entry-level communication adapters, the 1756-EN2TR supports dual ports and embedded switch technology, which allows for flexible network topologies, including device-level ring (DLR) redundancy. This ensures high availability of the network and minimizes downtime in case of a network disruption. The 1756-EN2TR is also designed with enhanced performance capabilities that support large systems with hundreds or thousands of nodes without sacrificing speed or reliability.

Key Features

One of the defining strengths of the 1756-EN2TR is its combination of robust hardware design and sophisticated network capabilities. It supports the latest standards in EtherNet/IP communication and is engineered to handle demanding applications such as motion control, safety I/O, and real-time data acquisition.

Here are some of the key features that make the 1756-EN2TR stand out:

• Dual-Port Connectivity: Two Ethernet ports allow the module to operate as an integrated switch, simplifying network wiring and enabling ring topologies for network resiliency.

• Device-Level Ring (DLR) Support: Built-in DLR functionality enables the module to detect and recover from single network faults in less than 3 milliseconds, ensuring continuous communication.

• High Data Throughput: Supports high-speed data rates up to 100 Mbps full-duplex, making it suitable for real-time applications such as motion control or safety systems.

• Integrated Security Features: Supports CIP Security for encrypted and authenticated communication, which is increasingly critical for protecting industrial control networks.

• Diagnostics and Troubleshooting: Offers detailed diagnostics through Studio 5000 Logix Designer software and web-based management, reducing downtime during maintenance.

• Scalability: Designed for small to very large systems, supporting up to 256 controller connections simultaneously.

• Energy Efficiency and Compact Design: Consumes less power than older modules and fits in a standard ControlLogix chassis without requiring additional power supplies.

Technical Specifications

The following table summarizes the key technical specifications of the Allen-Bradley 1756-EN2TR module:

This specification table gives a clear, concise view of the module’s capabilities and helps system designers confirm compatibility with their project requirements.

Application Scenarios

The 1756-EN2TR is deployed in a wide variety of industries where industrial Ethernet is the backbone of automation networks. Typical use cases include:

• Discrete Manufacturing: Automotive assembly lines, packaging machines, and high-speed material handling systems benefit from the module’s fast update rates and reliable I/O communication.

• Process Industries: In oil and gas, water treatment, and chemical processing, redundant communication paths supported by DLR ensure the system remains operational even if part of the network fails.

• Safety Systems: When combined with GuardLogix controllers, the 1756-EN2TR supports safety-rated communication for SIL-rated applications.

• Motion Control: The high throughput and low latency make it well-suited for coordinating multiple servo drives and motion axes in complex systems.

• Data Integration: The module can link controllers to MES (Manufacturing Execution Systems) and ERP (Enterprise Resource Planning) systems for enterprise-level visibility.

Benefits

Implementing the 1756-EN2TR brings several tangible benefits to an automation system:

• Improved Uptime: DLR support ensures that communication continues even if a cable is disconnected or a device in the ring fails.

• Reduced Wiring Costs: Dual-port architecture simplifies network cabling compared to traditional star topologies.

• Faster Troubleshooting: Built-in diagnostics allow technicians to quickly identify and resolve network issues.

• Scalability and Future-Proofing: The module can be used in both small systems and very large, plant-wide networks, protecting investments as systems expand.

• Enhanced Security: Support for CIP Security helps protect against network attacks and unauthorized access, aligning with modern cybersecurity best practices.

Installation and Configuration

Installing the 1756-EN2TR is straightforward for engineers familiar with the ControlLogix platform. The module simply slides into any open slot in a ControlLogix chassis and is automatically recognized by the system. Configuration is performed using Studio 5000 Logix Designer software, where users can assign an IP address, define the module’s role in the network, and set up redundancy if desired.

The embedded web server allows for additional flexibility, enabling configuration and diagnostics from any standard web browser without requiring specialized software. This feature is particularly useful for remote support or when quick checks need to be performed on the network.

Maintenance and Lifecycle Considerations

The 1756-EN2TR is designed for long-term use in industrial environments, with a rugged design that withstands temperature variations and electrical noise. Rockwell Automation provides regular firmware updates to enhance security and performance, ensuring the module stays up to date with the latest industry standards.

Preventive maintenance typically involves verifying network performance periodically, checking for firmware updates, and inspecting physical connections for wear or damage. Because of its reliability and support for diagnostics, the module often reduces the amount of unscheduled downtime compared to older communication modules.

Conclusion

The Allen-Bradley 1756-EN2TR is a robust, versatile, and high-performance communication module that serves as a backbone for modern EtherNet/IP-based automation systems. Its dual-port design, support for DLR, high data throughput, and integrated diagnostics make it an excellent choice for industries requiring reliable communication and minimal downtime. Whether used in small machine-level applications or large distributed control systems, the 1756-EN2TR offers the scalability, security, and performance needed to keep operations running smoothly.