Is Your ControlLogix Network Holding You Back?
Legacy communication modules often create bottlenecks that limit throughput and prevent you from adding new devices. The Allen-Bradley 1756-EN2TR solves this by providing a high-performance EtherNet/IP bridge with dual 10/100 Mbps ports, 128 TCP/IP connections, and support for up to 8 motion axes. This module is part of the ControlLogix series and installs in any chassis slot.
What Makes the 1756-EN2TR a Smart Upgrade?
The 1756-EN2TR is an Ethernet communication module from Allen-Bradley / Rockwell Automation. It supports general messaging, real-time I/O messaging, and information exchange for real-time control, time synchronization, and motion applications. With two RJ45 ports and one USB 1.1 port, it enables redundant Ethernet networks and simplifies programming workstation connections.
Technical Specs That Matter
Dual 10/100 Mbps Ports
Two RJ45 ports support linear and ring topologies, including Device Level Ring (DLR) and Parallel Redundancy Protocol (PRP). This increases network availability and reduces downtime.
128 TCP/IP Connections
With 128 TCP/IP connections and 256 Logix connections, the module handles large-scale I/O and messaging without dropping packets.
Integrated Motion Support
The 1756-EN2TR supports up to 8 axes for integrated motion on EtherNet/IP, eliminating the need for separate motion controllers.
Power and Thermal Efficiency
It draws 1 A at 5 V DC and 3 milliamps at 24 V DC, with 5.1 W power consumption and 21.28 BTU/hr thermal dissipation. This keeps cabinet heat low and extends component life.
Where the 1756-EN2TR Delivers Results
Automotive Assembly Lines
High-speed robot arms and conveyors rely on deterministic EtherNet/IP communication. The 1756-EN2TR supports real-time I/O and motion, ensuring synchronized production.
Food and Beverage Processing
Redundant ring topologies keep lines running even if a cable breaks. The module’s DLR support maintains communication, reducing costly stoppages.
Water Treatment Plants
SCADA and HMI systems require reliable data exchange. With 128 TCP/IP connections, the module connects controllers, drives, and third-party gateways seamlessly.
Installation and Setup
Install the 1756-EN2TR in any ControlLogix chassis slot. Use unshielded RJ45 Category 5 or 6 twisted-pair cables. Configure IP address, subnet mask, and gateway using the Allen-Bradley BOOTP-DHCP tool. No scheduling or routing tables are required, which simplifies commissioning.
Compatibility and Integration
The module works with Flex I/O, POINT I/O redundant Ethernet adapters, CompactLogix, and ControlLogix controllers. It also communicates with SLC 500, PLC-5, and MicroLogix controllers, as well as HMIs and SCADA systems. Third-party gateways and Encompass partner modules are supported.
Maintenance and Reliability
Inspect connections periodically and verify that the operating temperature stays within 32 to 140 °F (0 to 60 °C). The open enclosure requires a clean, dry environment. Because the module has no moving parts, wear is minimal. Regular firmware checks and network monitoring help prevent issues.
Selection Guide
Before purchasing, confirm your ControlLogix chassis has an open slot and that your network uses EtherNet/IP. You will need Category 5 or 6 cables and a BOOTP-DHCP tool for initial setup. For reliable supply and expert support, visit SpareTechPLC.
Frequently Asked Questions
What is the 1756-EN2TR used for?
It is an EtherNet/IP communication module for ControlLogix systems, enabling messaging, real-time I/O, and motion control.
How many TCP/IP connections does it support?
The module supports up to 128 TCP/IP connections and 256 Logix connections.
Can I use it for motion control?
Yes, it supports up to 8 axes for integrated motion on EtherNet/IP.
What cables do I need?
Use unshielded RJ45 Category 5 or 6 twisted-pair cables.
Does it support redundant networks?
Yes, it supports Device Level Ring (DLR) and Parallel Redundancy Protocol (PRP) for network redundancy.
