Overview
The Allen-Bradley 1756-CN2R Series B is a ControlLogix ControlNet redundant bridge module designed to establish high-speed, deterministic communication within distributed and redundant automation networks. This ControlLogix communication module is designed to establish ControlNet connectivity within distributed and redundant automation networks. It supports dual BNC ControlNet interfaces operating at 5 Mbps and includes a USB port for local configuration. Series B modules use a USB cable for temporary network connections.
Key Features
- Dual BNC ControlNet interfaces operating at 5 Mbps with USB port for local configuration
- Capacity for up to 128 Logix connections enabling high-performance, deterministic communication in large industrial systems
- Keeper capable module that becomes the Master Keeper if it has valid configuration and lowest address among keeper capable nodes, distributing network configuration information to other nodes
- Installs into any standard ControlLogix chassis and is compatible with both standard and redundant 1756 power supplies
- Applicable for implementing Distributed I/O topology covering up to 1000 meters per segment, easily extended with repeaters for longer segments
- Supports multi-node coaxial network structure using approved RG6 cabling, allowing long-distance I/O distribution and integration with HMIs and SCADA systems
Technical Specifications
- Communication Speed: 5 Mbps transmission speed supported
- Connections: Up to 128 Logix communication connections and 131 total network connections
- Network Nodes: Maximum of 99 nodes
- Network Interfaces: Double ControlNet BNC, a ControlNet RJ45, and a single USB 1.1 port
- Power Consumption: 1.3 A at 5.1 VDC and 3 mA at 24 VDC from the backplane
- Heat Dissipation: Up to 22.9 BTU/hr during operation
- Operating Temperature: 0 to 60 °C (32 to 140 °F) at 5–95% non-condensing relative humidity
- Dimensions: 7.87 in (200 mm) × 3.15 in (80 mm) × 1.65 in (42 mm)
- Vibration/Shock: 30G operational shock rate and maximum vibration of 2G at 10–500 Hz
- Certifications: UL Listed Industrial Control Equipment, UL Listed for Class I, Division 2 Group A,B,C,D Hazardous Locations, cULus UL Listed for US and Canada, certified for Class I, Division 2 Group A,B,C,D Hazardous Locations for U.S. and Canada
Typical Applications
- Industrial automation: Connecting ControlLogix PLCs to devices such as sensors, actuators, and other controllers on a ControlNet network
- Data acquisition and monitoring: Collecting data from sensors and other devices on the network
- Machine-to-machine communication: Enabling communication between machines on the factory floor
- Remote monitoring and control: Monitoring and controlling machines and processes from a remote location
Compatibility & Replacements
Compatible With
- ControlLogix 55xx and 5000 series Programmable Automation Controllers (PLCs)
- Standard and redundant 1756 power supplies including 1756-PA72/C, 1756-PA75/B, 1756-PB72/C, 1756-PB75/B, 1756-PC75/B, 1756-PH75/B, 1756-PA75R
- Standard ControlLogix chassis such as 1756-A4, 1756-A7, 1756-A10, 1756-A13, 1756-A17
- ControlNet network using the Common Industrial Protocol (CIP) combining I/O network and peer-to-peer network functionality
Replaces / Drop-In Replacement For
- Allen-Bradley 1756-CN2 Series A (with different cable configuration — Series A uses 1786-CP cable; Series B uses USB)
- Verify compatibility with your system integrator before ordering for specific upgrade paths.
Works With
- Rockwell Automation RSLogix 5000 / Studio 5000 programming software
- ControlLogix 55xx and 5000 series controllers
- RSLogix 5000 Enterprise Series software supporting generic ControlNet module configuration for connections to ControlNet nodes
- HMI and SCADA systems via ControlNet network
- RG6 quad shield coaxial cabling (1786-RG6) for ControlNet network connections
