Allen-Bradley 1756-EN2T/C EtherNet/IP Communication Module

The Allen-Bradley 1756-EN2T/C, also cataloged as the 1756-EN2T communication module, operates as a dedicated hardware component for EtherNet/IP data routing and controller-to-network execution within ControlLogix chassis architectures. Configured for deterministic Ethernet communication in 1756 ControlLogix systems, the Allen-Bradley 1756-EN2T/C (1756-EN2T communication module) provides direct backplane-mediated CIP messaging and dual-port Ethernet frame handling for real-time data exchange.

Hardware Specifications

ControlLogix Backplane and EtherNet/IP Deterministic Communication Behavior

The module executes EtherNet/IP cyclic and explicit messaging through the ControlLogix backplane bus, where communication scheduling is aligned with controller task execution cycles. The /C hardware revision implements updated internal packet handling logic, affecting frame buffering and CIP connection arbitration behavior.

Backplane communication is governed by slot-based bandwidth allocation, where module-to-CPU data transfer occurs through synchronized producer-consumer mechanisms. Dual RJ-45 ports support linear, star, and device-level ring topologies without external routing hardware.

Frequently Asked Questions (FAQ)

Q: Does the 1756-EN2T/C support hot-swap insertion under chassis power?
A: Yes. The module supports hot insertion and removal in a powered ControlLogix chassis. Backplane re-enumeration occurs after slot detection and initialization.

Q: How does backplane current draw affect chassis configuration?
A: The module draws approximately 1.0 A at 5 VDC from the chassis backplane. Total rack power budget must account for cumulative module loading across all installed slots.

Q: Is CIP connection capacity affected by firmware revision differences?
A: Yes. Firmware mismatch between controller and communication module may reduce available CIP connections or prevent explicit messaging session establishment.

Field Installation Guidelines

Insert the module into a compatible 1756 ControlLogix chassis slot with proper alignment to the backplane connector. Ensure full seating to guarantee electrical continuity and signal integrity. Use shielded twisted-pair Ethernet cabling with controlled grounding at the switch-side reference point. Maintain separation between Ethernet wiring and high-voltage conductors to minimize electromagnetic coupling. Configure IP parameters through BOOTP/DHCP or controller-based network configuration prior to runtime operation.