1756-CN2R | Allen-Bradley | ControlLogix ControlNet Communication Module

Overview

The Allen-Bradley 1756-CN2R is a ControlLogix ControlNet communication bridge module designed to provide reliable high-speed network connectivity for PLC systems. Supporting up to 99 nodes and 131 simultaneous connections, this module enables efficient data exchange between ControlNet-enabled devices and the ControlLogix chassis. Ideal for both standard and redundant network configurations, it ensures consistent performance in demanding industrial environments.

Technical Specifications

• Manufacturer: Allen-Bradley (Rockwell Automation)

• Model / Part Number: 1756-CN2R

• Product Type: ControlLogix Communication Module

• Series: ControlLogix

• Module Type: Bridge Module

• Maximum Nodes: 99

• Maximum Connections: 131

• ControlNet Data Rate: 5 Mbps

• Number of ControlNet Ports: 2

• USB Port: 1 (Data rate 12 Mbps)

• Backplane Current Draw: 1.3 A at 5.1 VDC; 3 mA at 24 VDC

• Power Dissipation (Max): 6.7 W

• Thermal Dissipation: 22.9 BTU/hr

• Isolation Voltage: 30 VDC continuous

• Compatible Standard Power Supplies: 1756-PA72/C, 1756-PA75/B, 1756-PB72/C, 1756-PB75/B, 1756-PC75/B, 1756-PH75/B

• Compatible Redundant Power Supplies: 1756-PA75R, 1756-PB75R, 1756-PSCA2

• Compatible Chassis: 1756-A4, 1756-A7, 1756-A10, 1756-A13, 1756-A17

• ControlNet Cable: 1786-RG6 quad shield RG6 coaxial cable

• Mounting: Any 1756 chassis, slot width 1

• Dimensions (L×W×H): 5.51 × 4.41 × 5.71 in (14 × 11.2 × 14.5 cm)

• Weight: 0.94 lbs (0.43 kg)

• Operating Temperature: 0–60 °C (32–140 °F)

Key Features

• High-speed ControlNet communication for large-scale PLC systems

• Supports redundant network configurations for critical applications

• Backplane-compatible with all standard ControlLogix chassis

• Low power consumption with efficient thermal management

• Provides two ControlNet ports plus one USB port for flexible connectivity

Applications

• Network bridge for ControlNet PLC systems

• Integration of multiple ControlLogix modules in manufacturing and process control

• Redundant network setups requiring reliable communication and failover

FAQs

Q1: How many nodes can the 1756-CN2R support?
The module supports up to 99 ControlNet nodes, suitable for large networked PLC systems.

Q2: Can it operate with redundant power supplies?
Yes, it is compatible with redundant units such as 1756-PA75R, 1756-PB75R, and 1756-PSCA2.

Q3: What chassis are compatible?
Compatible with 1756-A4, A7, A10, A13, and A17 chassis.