Product Details
Module Overview
The 1756-EN3TR is a high-performance Ethernet/IP communication interface specifically engineered for the Allen-Bradley ControlLogix platform. Featuring a built-in two-port switch, this module facilitates high-speed data exchange, distributed I/O control, and seamless integration with industrial networks. It is a cornerstone for modern automation architectures, supporting advanced networking features such as Device Level Ring (DLR) for enhanced system resiliency and Integrated Motion on EtherNet/IP for precise synchronized axis control.
Detailed Engineering Specifications
The 1756-EN3TR is designed to occupy a single slot in any standard 1756 chassis, drawing power directly from the backplane to manage complex network traffic and motion synchronization.
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Module Type: EtherNet/IP Communication Interface
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Physical Ports: Two (2) Ethernet (RJ-45) and One (1) USB 1.1 (Type B)
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Ethernet Transfer Speed: 10/100 Mbps (Full/Half Duplex)
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USB Transfer Rate: 12 Mbps (Local configuration/Programming)
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Network Topologies: Linear, Star, and Device Level Ring (DLR)
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Backplane Current (5.1V DC): 1.0 Ampere
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Backplane Current (24V DC): 3 Milliamps
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Total Power Dissipation: 5.1 Watts
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Thermal Dissipation: 17.4 BTU/hr
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Integrated Motion Support: Up to 128 Axes of motion
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Isolation Voltage: 30V Continuous (Basic Insulation Type)
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Operating Temperature: 0°C to 60°C (32°F to 140°F)
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Chassis Compatibility: 1756-A4, -A7, -A10, -A13, -A17 (Series B and C)
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Slot Width: Single-slot occupancy
Networking Capabilities and Topology Support
A primary advantage of the 1756-EN3TR is its native support for Device Level Ring (DLR) technology. In a DLR configuration, the module's dual ports allow the network to be wired in a physical ring. If a single cable failure occurs, the module automatically reroutes traffic, ensuring the PLC system remains operational without a loss of I/O control. This high-availability feature is critical for large-scale manufacturing lines and process plants where downtime is costly.
Integrated Motion on EtherNet/IP
The 1756-EN3TR is optimized for high-performance motion control. It is capable of managing up to 128 axes of Integrated Motion on EtherNet/IP, allowing the ControlLogix processor to synchronize servo drives (such as Kinetix series) directly over the standard Ethernet network. This eliminates the need for specialized SERCOS hardware and simplifies the wiring of multi-axis machines.
Technical FAQ
Can the two Ethernet ports be assigned different IP addresses?
No. The two RJ-45 ports on the 1756-EN3TR act as an internal unmanaged switch. They share a single MAC address and a single IP address. They are intended for daisy-chaining or creating a DLR ring, not for bridging two separate subnets.
What is the function of the USB port on the front faceplate?
The USB port is intended for local configuration and temporary programming access. It allows a technician to connect a laptop directly to the module to configure the IP address or perform firmware updates via RSLinx without needing to be on the primary network.
Is this module compatible with standard 1756 power supplies?
Yes. The 1756-EN3TR is fully compatible with all standard ControlLogix power supplies (e.g., 1756-PA72, 1756-PB75) and redundant power supply configurations (e.g., 1756-PA75R).
Additional Information
- 100% Genuine Parts: All products are original and authentic, ensuring reliable industrial performance.
- 30-Day Refund Guarantee: Return any in-stock item within 30 days in original, unopened packaging for a full refund (excluding shipping and fees).
- 12-Month Warranty: Covers defects in materials or workmanship; excludes misuse, normal wear, or unauthorized modifications.
- Worldwide Shipping: We ship via USPS, UPS, FedEx, and DHL. Delivery times vary by country and may be subject to customs or import fees.
- Support & Contact: Technical and warranty assistance is available anytime. Contact us here: Contact.
- Purchase Guidance: Check product specifications and compatibility carefully before ordering to ensure proper application.
Tech & Buying Guide
Understanding Root Causes of Unplanned PLC Stop Mode in Industrial Automation
Modern Programmable Logic Controllers manage execution through distinct operational states: Run, Stop, Start-Up, and Hold. During power-up, a controller initializes memory registers within Stop mode before briefly transitioning to Start-Up mode. During this phase, internal self-diagnostics evaluate system integrity across hardware and user programs. If the controller detects no critical faults, it enters Run mode to execute the control program continuously. However, any severe system anomaly forces the CPU back into Stop mode immediately to prevent erratic machine behavior across the plant floor.
Human-Machine Interface Design: Essential Guide to HMI Selection, Visualization, and Control System Integration
Human-Machine Interfaces (HMIs) serve as the primary operational window into complex industrial automation systems. Modern HMIs convert raw machine data into clear graphical displays, enabling operators to oversee entire manufacturing processes in real time. Instead of relying on physical control panels full of hardwired switches, engineers program interactive screens using intuitive graphics, dynamic color coding, and responsive touch interfaces. Over my 15 years in control systems engineering, I have observed HMIs transform from basic display screens into sophisticated command centers that drive operational efficiency across DCS and PLC environments.
Understanding Safety Relays in Industrial Automation: Architecture, Operation, and Functional Safety
Standard electromechanical relays provide basic electrical isolation between low-voltage control circuits and high-power output loads. A traditional switching relay features a magnetic coil driving mechanical Common (COM), Normally-Open (NO), and Normally-Closed (NC) contacts. However, standard relays pose severe functional risks when deployed in critical safety interlock circuits. High current inrush or mechanical wear can weld contacts together permanently. If contact welding occurs in an emergency stop circuit, pressing the button fails to halt hazardous machinery movements. Consequently, global functional safety standards prohibit standard relays for critical machine guarding functions.