• Allen-Bradley 1756-CN2R/B
  • Allen-Bradley 1756-CN2R/B
  • Allen-Bradley 1756-CN2R/B
1 3

Allen-Bradley 1756-CN2R/B ControlNet Redundant Communication Module

Allen-Bradley 1756-CN2R/B ControlNet Redundant Communication Module

The Allen-Bradley 1756-CN2R/B is a Series B ControlNet communication bridge module engineered for the ControlLogix platform. This module facilitates deterministic, high-speed data exchange between controllers, remote I/O, and field devices....

16 people are viewing this right now

Availability: Low stock: 4 left

SKU: 1756-CN2R/B
Vendor: Allen-Bradley
Category: Communication Module
Related Series:

Shipping & Returns

Reliable Worldwide Delivery

  • Carriers: Shipped via DHL, FedEx, UPS, or USPS.
  • Dispatch: Orders processed in 1-2 business days and dispatched within 3-5 business days.
  • Tracking: Full tracking details provided via email upon shipment.

30-Day Money-Back Guarantee

  • Guarantee: 30-day return window for in-stock, factory-sealed products.
  • Condition: Items must be unopened, unused, and in original packaging.
  • Authenticity: We guarantee 100% original and authentic hardware.

Need more details? Read our fullShipping PolicyandRefund Policy.

Authenticity & Warranty

  • Genuine Guarantee: We supply only 100% original, brand-new, and factory-sealed industrial automation parts.
  • Full Coverage: Every component is backed by a 12-month comprehensive warranty from the date of purchase.
  • Traceability: All products come with original factory documentation and accessories for full industrial compliance.

Technical Support & Sourcing

  • Expert Assistance: Our technical team provides free consultation to help you verify compatibility for DCS and PLC systems.
  • Rare Part Sourcing: Specializing in obsolete and hard-to-find components from Allen-Bradley, Siemens, ABB, HIMA, and more.
  • Bulk Inquiries: Contact us at pambo@5gplc.com for volume pricing or customized project quotes.
View full product details

The Allen-Bradley 1756-CN2R/B is a Series B ControlNet communication bridge module engineered for the ControlLogix platform. This module facilitates deterministic, high-speed data exchange between controllers, remote I/O, and field devices. By utilizing a dual-channel coaxial architecture, the 1756-CN2R/B provides critical redundancy, ensuring continuous network operation even in the event of a single-cable failure or signal degradation.

Features

  • Redundant Media Support: Dual BNC connectors allow for redundant ControlNet cabling, enabling automatic failover if a primary link is compromised.
  • Deterministic Throughput: Maintains a constant 5 Mbps data rate, essential for time-critical control applications.
  • High Capacity: Supports up to 99 nodes on a single network and manages up to 131 total connections (128 of which are dedicated to Logix controllers).
  • Integrated USB Port: Includes a dedicated USB port for local configuration and diagnostic access.
  • Series B Reliability: Optimized hardware design for improved stability and performance in demanding industrial environments.

Installation Guidelines

  • ESD Protection: Always utilize an ESD wrist strap or similar grounding device when handling the module to prevent damage to sensitive internal components.
  • Backplane Insertion: Ensure the ControlLogix chassis is powered down before inserting or removing the module. Align the module with the chassis guides and seat firmly to ensure proper backplane connection.
  • Cabling: Use only 1786-RG6 quad-shield coaxial cables for network connections to maintain signal integrity and meet specification requirements.
  • Environmental: Mount the module in an environment that maintains an ambient temperature between 0 and 60 degC. Ensure adequate airflow around the chassis to prevent heat buildup.
  • Grounding: Ensure the ControlLogix chassis is properly grounded according to local electrical codes to minimize EMI impacts.

Technical Specifications

Model 1756-CN2R/B
Series Series B
Communication Speed 5 Mbps
Max Nodes 99
Max Connections 131 (128 Logix)
Power Dissipation 6.7 W
Backplane Current (5.1V) 1300 mA
Operating Temperature 0 to 60 degC
Enclosure Type Open Type

FAQ

Q: Does this module support non-redundant configurations?
A: Yes, the 1756-CN2R/B can operate in a single-cable configuration, though it is specifically designed to provide redundant media capability for high-availability systems.

Q: What is the primary difference between Series A and Series B?
A: The Series B hardware revision features updated internal processing components for improved reliability and firmware compatibility within the ControlLogix ecosystem.