Allen-Bradley 1756-CN2RK ControlLogix ControlNet Bridge Module

Configured for deterministic ControlNet data bridging in ControlLogix redundant communication architectures, the Allen-Bradley 1756-CN2RK (1756-CN2RK Bridge Module) provides direct physical and protocol-level execution of dual-channel ControlNet communication at 5 Mbps across redundant network paths within a ControlLogix backplane system. The module supports up to 99 network nodes and manages up to 131 simultaneous connections through scheduled network execution.

Aligned with Rockwell Automation ControlLogix communication framework, the module performs backplane-synchronized ControlNet bridging with dual-channel redundancy and conformal-coated PCB protection for environmental stability in electrically noisy installations.

Suffix Breakdown & Model Matrix

Single defined configuration: 1756-CN2RK ControlNet redundant bridge module. No additional functional suffix segmentation specified.

Hardware Specifications

ControlNet Dual-Channel Bridge Execution Architecture

The 1756-CN2RK executes ControlNet frame forwarding through deterministic scheduling at 5 Mbps network rate, synchronizing redundant channel propagation across dual communication paths. Backplane bus communication velocity is managed through ControlLogix system timing, ensuring consistent frame alignment between controller task execution and network transmission cycles.

The module supports I/O and controller node aggregation up to 99 devices, with connection handling capacity of 131 logical links distributed across scheduled network intervals. Redundant channel operation maintains parallel data stream integrity at the media interface layer without interrupt arbitration at application level.

Frequently Asked Questions (FAQ)

Q: Does the 1756-CN2RK support hot-swap in ControlLogix chassis?
A: Yes. The module supports hot insertion and removal. Reinitialization is handled through ControlLogix backplane rescan and configuration reload.

Q: What is the limitation of ControlNet node count?
A: The module supports a maximum of 99 nodes, constrained by ControlNet scheduling bandwidth at 5 Mbps.

Q: How is redundancy implemented between channels?
A: Dual-channel redundancy operates at the network interface layer with synchronized frame transmission across both ControlNet paths.

Field Installation Guidelines

Install the module into a compatible ControlLogix chassis ensuring full backplane connector engagement to maintain deterministic timing alignment. ControlNet coaxial cabling must follow impedance-controlled routing with continuous shield integrity across trunk and drop segments.

Maintain separation between ControlNet communication lines and high-current power conductors to reduce induced electromagnetic coupling. Shield grounding must be implemented using a single-point earth reference to avoid loop currents across redundant channels.

Verify firmware compatibility between controller, chassis, and communication module prior to commissioning to ensure correct backplane scheduling synchronization and network timing alignment.