Allen-Bradley

Allen-Bradley 1756-CNBR ControlLogix ControlNet Interface Module

SKU 1756-CNBR

In stock
  • 12-month warranty
  • Free returns within 30 days

  • Manufacturer: Allen-Bradley

  • Product No.: 1756-CNBR

  • Country of origin:United States

  • Product Type: ControlLogix Communication Module

  • Barcode: 8537101190

  • Payment: T/T, Western Union

  • Weight: 320g

  • Dimensions: 130 mm x 145 mm x 35 mm (H x W x D)

  • Shipping port: Xiamen

  • Warranty: 12 months

Description

The Allen-Bradley 1756-CNBR is a ControlLogix ControlNet interface module designed to provide high-speed, deterministic communication and media redundancy for ControlLogix chassis architectures. Operating within a ControlLogix system chassis, the module handles real-time data transfer, network scheduled connections, and backplane interface diagnostics. The 1756-CNBR module features dual ControlNet ports for redundant-media configurations, enabling reliable communication links across process control architectures and remote I/O layouts. Up to five ControlLogix controllers can establish rack optimization connections to a single remote adapter module.

Features

  • Dual ControlNet connectors supporting redundant-media physical configurations.
  • Integrated 4-character diagnostic scrolling LED display showing module status, error messages, and unconnected buffer usage.
  • Internal 16-bit minor fault counters for monitoring bandwidth, network errors, and ControlBus backplane errors via CIP generic messaging.
  • ControlNet International (CI) conformance tested for standard network compliance.
  • Optimized for integration into ControlLogix Redundancy systems.

Applications

  • Redundant communication links in industrial ControlLogix PLC process control systems.
  • Remote I/O communication and rack optimization across ControlNet networks.
  • Inter-controller messaging and scheduled data exchange in automated architectures.

Ordering Information

Catalog Number Description
1756-CNB/D ControlLogix ControlNet Interface Module, Single-Media, Series D
1756-CNBR/D ControlLogix ControlNet Interface Module, Redundant-Media, Series D

Technical Specifications

Parameter Specification
Manufacturer Allen-Bradley / Rockwell Automation
Catalog Number 1756-CNBR
Module Type ControlNet Interface Module (Redundant-Media)
Series Series D
Diagnostic Display 4-character scrolling display
Internal Counters 16-bit minor fault counters (Bandwidth, Network Error, ControlBus Receive Error, ControlBus Address Error)
Unconnected Buffers Up to 20 client buffers and 20 server buffers
Rack Optimization Limit Maximum 5 controllers per remote adapter module

Installation Guidelines

  • Ensure the ControlNet network cable is properly terminated at all ends to avoid communication faults and module assertion errors.
  • Do not set the module node address switches to 00 in any system, or to 99 in a redundant system.
  • Limit rack optimization configurations to a maximum of five controllers per remote adapter to prevent connection resource errors (16#011a).
  • Verify proper seating of the module into the ControlLogix chassis backplane slot.

Compliance and Certifications

  • ControlNet International (CI) Conformance Tested

FAQ

How many controllers can configure rack optimization on the module?
A maximum of five ControlLogix controllers can establish rack optimization connections to a single remote adapter module.

How are diagnostic status messages displayed on the device?
Diagnostics, error messages, and unconnected buffer status are displayed on the integrated 4-character scrolling display on the front panel.

What happens if the ControlNet network cable is left unterminated?
Leaving the network cable unterminated for extended periods can cause the module to experience fault conditions or display assertion errors.

View all FAQs →

Product Documentation

Technical Datasheet (PDF) Complete specifications and technical drawings.

Technical Datasheet

Allen-Bradley 1756-CNBR ControlLogix ControlNet Interface Module

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  • Standard Delivery: 4–6 business days via DHL, FedEx, and UPS.
  • Express Dispatch: Same-day dispatch for in-stock orders placed before 2:00 PM (GMT+8).
  • Worldwide Coverage: Serving over 150 countries.

Returns & Warranty

  • 30-Day Guarantee: Returns accepted for in-stock products in original, factory-sealed packaging.
  • 12-Month Warranty: Every industrial component is backed by our technical warranty.
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Global Express Shipping

  • Standard Delivery: 4-6 Business Days via DHL, FedEx, and UPS.
  • Express Dispatch: Same-day dispatch for in-stock orders placed before 2:00 PM (GMT+8).
  • Worldwide Coverage: Serving over 150 countries, including rapid delivery to Saudi Arabia and UAE.

Returns & Warranty

  • 30-Day Guarantee: Returns accepted for in-stock products in original, factory-sealed packaging.
  • 12-Month Warranty: Every industrial component is backed by our professional technical warranty.

Orders are processed and delivered Monday-Friday (excluding public holidays).


For full eligibility, restocking fees, and international return details, please view our official Refund & Return Policy .

TECHNICAL SPECIFICATIONS

Color pattern
Black
Country of origin
United States
Power source
DC Power

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