Allen-Bradley 1756-EN2TK EtherNet/IP Communication Module

Configured for secure high-speed controller-to-network data exchange in ControlLogix chassis systems, the Allen-Bradley 1756-EN2TK (1756-EN2T communication module) provides direct physical and protocol-level execution for EtherNet/IP CIP traffic with integrated security enforcement, including encrypted session handling and authenticated communication within industrial Ethernet networks.

The module implements deterministic CIP messaging across Ethernet backplane routing paths, with security extensions applied at session establishment and data transport layers.

Suffix Breakdown & Model Matrix

The base identifier 1756-EN2T defines the EtherNet/IP communication architecture. The K suffix indicates a security-enhanced hardware revision incorporating CIP Security capabilities, TLS-based session encryption, and authentication enforcement. No additional functional segmentation beyond revision-level security extension is defined.

Hardware Specifications

ControlLogix Backplane Communication & CIP Security Execution Layer

The module operates through the 1756 backplane arbitration system, where chassis slot scheduling governs cyclic data exchange timing. EtherNet/IP implicit messaging is executed via CIP objects with secure session encapsulation when enabled.

CIP Security enforces identity validation using certificate-based authentication prior to session activation. TLS encryption is applied to payload transport, increasing frame processing overhead relative to non-secure EN2T variants. Firmware compatibility must align with both controller revision and security policy set. Backplane bus communication velocity is dependent on chassis power distribution and slot scan allocation. I/O density scaling is limited by simultaneous secure session capacity under encryption overhead conditions.

Frequently Asked Questions (FAQ)

Q: Does the 1756-EN2TK support hot-swap in an active ControlLogix chassis?
A: Yes. The module supports hot-swap insertion and removal. Secure CIP sessions terminate and reinitialize after reinsertion.

Q: Does enabling CIP Security affect CIP connection capacity?
A: Yes. Encrypted sessions introduce additional handshake and encryption overhead, reducing effective connection throughput under maximum load.

Q: Is firmware alignment required for secure communication operation?
A: Yes. CIP Security requires matched firmware versions across controller, module, and certificate policy configuration.

Field Installation Guidelines

Install the module into a compatible 1756 ControlLogix chassis with power removed when possible. Ensure full seating on the backplane connector to maintain stable electrical and communication alignment. Configure security certificates before enabling CIP Security traffic. Use shielded twisted-pair Ethernet cabling and maintain proper chassis grounding to reduce EMI coupling on RJ-45 interfaces. Route Ethernet cables separately from high-voltage conductors. Verify IP addressing, security policy configuration, and firmware compatibility prior to commissioning.