SKU: 1756-CNBR

Allen-Bradley 1756-CNBR ControlLogix Communication Module

The Allen-Bradley 1756-CNBR is a redundant ControlNet bridge module for ControlLogix systems. It provides 5 Mbps deterministic communication and dual BNC ports for media redundancy. This module supports up to 64 connections and 99 nodes in mission-critical automation environments.

The Allen-Bradley 1756-CNBR serves as a high-performance communication interface for the ControlLogix platform. This bridge module facilitates deterministic data exchange across ControlNet networks. It specifically supports media redundancy through dual BNC connectors. This design ensures continuous system operation if one cable path fails. Engineers utilize this module to connect controllers, I/O chassis, and other ControlNet-enabled devices. It functions effectively in both local and remote chassis configurations.

Technical Specifications

Manufacturer: Rockwell Automation / Allen-Bradley
Module Type: ControlNet Bridge Redundancy Module
Communication Rate: 5 Mbps
Logix Connections: 64 Bidirectional
Maximum Nodes: 99
Current Draw (5.1V DC): 970 mA
Current Draw (24V DC): 1.7 mA
Power Dissipation: 5.1 Watts
Thermal Dissipation: 17.4 BTU/hr
Slot Width: 1 (Single Slot)
Network Ports: 2 BNC (Redundant) and 1 RJ45 (NAP)

Core Functional Characteristics

This module manages scheduled and unscheduled messaging simultaneously. Scheduled traffic provides deterministic delivery for critical control data. Unscheduled traffic handles low-priority tasks like configuration and diagnostics. The 1756-CNBR supports redundant media to maximize network uptime. This feature proves essential for high-availability industrial applications. The integrated Network Access Port (NAP) allows for local programming via a laptop. Users can install the module in any available slot in a ControlLogix chassis.

Application and Integration

The 1756-CNBR acts as a gateway between the backplane and the network. It allows ControlLogix processors to control distributed I/O over long distances. System integrators often deploy this module in process control and manufacturing environments. The bridge supports quad-shield RG-6 coaxial cabling for superior noise immunity. It maintains compatibility with all 1756 series chassis and power supplies. Reliable hardware design ensures stability in harsh electromagnetic conditions.