Allen-Bradley 1756-EN2TR ControlLogix EtherNet/IP Module

High-Capacity Dual-Port Communication Bridge

The Allen-Bradley 1756-EN2TR is a high-performance EtherNet/IP communication bridge module designed for the ControlLogix platform. This module facilitates seamless data exchange between the controller and various network devices, including distributed I/O, other controllers, and HMI/SCADA systems. Because it features two built-in Ethernet ports, it inherently supports Device Level Ring (DLR) topologies. This capability provides a resilient network infrastructure that can survive a single point of failure (such as a cut cable) without losing communication. Consequently, the 1756-EN2TR is a standard choice for mission-critical industrial applications requiring high uptime and deterministic performance.

Core Technical Specifications

• Manufacturer: Allen-Bradley / Rockwell Automation
• Model Number: 1756-EN2TR
• Module Type: EtherNet/IP Communication Bridge (High Capacity)
• EtherNet/IP Ports: 2 RJ45 ports
• Communication Rate: 10/100 Mbps (Full or Half Duplex)
• CIP Connections: Up to 256
• TCP/IP Sessions: Up to 128
• Logix Communication Rate: 10,000 packets per second (pps)
• Backplane Current: 1.0 A @ 5.1V DC
• Power Dissipation: 5.1 Watts
• Physical Weight: 0.9 kg
• Manufacturing Origin: USA

Advanced Networking and Safety Integration

The 1756-EN2TR maximizes system versatility by supporting CIP Safety and CIP Motion protocols. This allows engineers to run safety-rated signals and high-precision synchronized motion axis data over the same physical Ethernet cable, reducing wiring complexity and costs. Furthermore, the module acts as a “communication bridge,” enabling users to browse through the backplane to other networks like ControlNet or DeviceNet without additional programming. Moreover, the module supports “Linear,” “Star,” and “Ring” topologies, giving designers the flexibility to match the network layout to the physical plant floor. Since it is a high-capacity module, it can handle significantly more traffic and connected devices than the standard 1756-ENBT, making it suitable for large-scale automation architectures.

Primary Industrial Applications

• Process Automation: Connecting ControlLogix processors to distributed 1756, 1794 (FLEX), and 5069 I/O systems.
• Motion Control: Synchronizing Kinetix servo drives over EtherNet/IP for multi-axis machinery.
• Redundant Networking: Utilizing the dual ports for Device Level Ring (DLR) to ensure zero-recovery-time redundancy.
• SCADA Interfacing: Serving as the high-speed gateway for FactoryTalk View and third-party HMI software.