Allen-Bradley 1756-EN27 ControlLogix EtherNet/IP Bridge Module

Configured for real-time industrial Ethernet communication in ControlLogix architectures, the Allen-Bradley 1756-EN27 (1756-EN27 EtherNet/IP Bridge Module) provides direct backplane-to-network data exchange between ControlLogix controllers and EtherNet/IP nodes. The module executes deterministic CIP messaging through dual RJ-45 interfaces and interfaces with the 1756 chassis backplane for cyclic and explicit data handling.

Suffix Breakdown & Model Matrix

The 1756-EN27 is a single-order ControlLogix communication module without documented suffix segmentation. No functional sub-variants or field-selectable model branches are defined in the provided specification. All operational behavior is fixed at firmware and backplane configuration level within the ControlLogix system.

Hardware Specifications

ControlLogix EtherNet/IP Backplane Communication Characteristics

The module integrates into the ControlLogix backplane bus architecture, where cyclic I/O updates and explicit messaging are scheduled via chassis arbitration. EtherNet/IP frame handling is synchronized through firmware-level task execution linked to controller scan cycles. Dual-port architecture supports line, star, and ring topologies without external bridging logic.

Backplane throughput is constrained by 5 VDC current draw profile and chassis slot arbitration timing. CIP object routing is executed through the module’s embedded network stack with deterministic packet handling aligned to ControlLogix task scheduling.

Frequently Asked Questions (FAQ)

Q: Does the 1756-EN27 support hot-swap replacement under chassis power?
A: Yes, the module supports hot-swap insertion and removal in a powered 1756 ControlLogix chassis. Backplane re-enumeration occurs after slot re-detection.

Q: What is the effect of backplane current draw on chassis loading?
A: The module draws approximately 1.0 A at 5 VDC from the backplane. Total chassis power budget must account for cumulative slot loading.

Q: Can firmware mismatch affect EtherNet/IP communication stability?
A: Yes, controller and module firmware mismatch may cause CIP connection rejection or reduced connection allocation capacity.

Field Installation Guidelines

Insert the module into an available 1756 ControlLogix chassis slot with power removed or per hot-swap procedure. Ensure backplane connector alignment before full seating. Use shielded Ethernet cabling with proper grounding at the switch or control cabinet earth reference. Maintain separation between Ethernet and high-voltage conductors to reduce induced noise coupling. Configure IP addressing through controller or BOOTP/DHCP tool prior to runtime commissioning.