Description
1. At-A-Glance Executive Brief
- Model: 1756-EN2TR
- Brand: Allen-Bradley (Rockwell Automation)
- Part Type: ControlLogix EtherNet/IP Communication Bridge Module
- Lifecycle Status: Active / Mature Support Tier
- Core Protocol: EtherNet/IP, CIP, IEEE 1588 Precision Time Protocol
- Weight: 0.28 kg
2. Technical Introduction
Problem-Agitation-Solution format. Mention a common issue this part solves, followed by how it functions in the DCS/PLC rack.
Plant automation networks wired in standard star topologies frequently experience complete cell-area communication dropouts when a single unmanaged Ethernet cable or switch port fails, halting production lines. Standard interface cards lack integrated media-ring protocols, leaving critical controllers vulnerable to single-point-of-failure network outages. The Allen-Bradley 1756-EN2TR resolves this by embedding dual RJ45 ports that natively support Device-Level Ring (DLR) topologies directly inside the ControlLogix chassis, ensuring fault-tolerant ring architecture and seamless message bridging across plant-wide EtherNet/IP networks.
3. Core Technical Specifications
| Parameter | Value |
| Network Communication Rate | 10/100 Mbps (Full/Half Duplex) |
| Ports | 2 x RJ45 (Embedded switch for DLR) |
| Slot Width | 1 ControlLogix chassis slot |
| Backplane Current Draw | 1.0 A @ 5.1V DC, 3 mA @ 24V DC |
| Isolation Voltage | 30V (continuous), basic insulation type |
| Max Connected Nodes | 256 Ethernet nodes per module |
| Enclosure Rating | None (Open-type equipment) |
| Operating Temperature | 0 to 60°C |
4. Field Engineer’s Tech Notes
- Device-Level Ring (DLR) Configuration: When integrating this module into a DLR topology, ensure that one node on the ring is configured as the active Ring Supervisor via RSLinx or Studio 5000, while all other nodes act as ring participants. Misconfigured supervisors cause redundant beacon packet loops and network saturation.
- Firmware Revision and CIP Security: The 1756-EN2TR must be flashed to a major firmware revision that matches your controller project file to avoid messaging timeouts. If upgrading older Series hardware, verify that your RSLinx Enterprise or FactoryTalk Linx communication drivers recognize the updated EDS profile before attempting online tag browsing.
5. Adaptive QA & Testing Protocol
Every 1756-EN2TR communication module undergoes bench verification prior to inventory release. Technicians mount the card into an active ControlLogix chassis test rack and execute full packet transmission tests across both RJ45 ports using specialized network simulation tools. Node handshake verification, CIP messaging throughput checks, and DLR beacon recovery tests are performed under live traffic conditions to ensure zero packet loss and stable backplane communication. Comprehensive test logs and verification videos are available upon request to support your compliance audits.
6. Buyer’s FAQ
- Q: What warranty is provided with this communication module? A: All New Surplus and fully tested units include a comprehensive 24-month replacement warranty covering hardware integrity and communication performance.
- Q: Does this module support DLR (Device-Level Ring) network architectures? A: Yes, the dual embedded Ethernet ports support physical ring topologies to deliver fault-tolerant media redundancy without requiring external switches.
- Q: Can this module be installed in any slot of a ControlLogix chassis? A: Yes, the 1756-EN2TR can reside in any slot of a 1756 chassis, and multiple communication modules can be installed in a single rack for increased bandwidth or network segmentation.
- Q: What are the shipping lead times for emergency breakdown situations? A: Expedited same-day shipping
