Product Details
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
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Manufacturer: Allen-Bradley (Rockwell Automation)
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Model / Part Number: 1756-CN2R
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Product Type: ControlLogix Communication Module
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Series: ControlLogix
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Module Type: Bridge Module
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Maximum Nodes: 99
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Maximum Connections: 131
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ControlNet Data Rate: 5 Mbps
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Number of ControlNet Ports: 2
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USB Port: 1 (Data rate 12 Mbps)
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Backplane Current Draw: 1.3 A at 5.1 VDC; 3 mA at 24 VDC
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Power Dissipation (Max): 6.7 W
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Thermal Dissipation: 22.9 BTU/hr
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Isolation Voltage: 30 VDC continuous
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Compatible Standard Power Supplies: 1756-PA72/C, 1756-PA75/B, 1756-PB72/C, 1756-PB75/B, 1756-PC75/B, 1756-PH75/B
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Compatible Redundant Power Supplies: 1756-PA75R, 1756-PB75R, 1756-PSCA2
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Compatible Chassis: 1756-A4, 1756-A7, 1756-A10, 1756-A13, 1756-A17
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ControlNet Cable: 1786-RG6 quad shield RG6 coaxial cable
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Mounting: Any 1756 chassis, slot width 1
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Dimensions (L×W×H): 5.51 × 4.41 × 5.71 in (14 × 11.2 × 14.5 cm)
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Weight: 0.94 lbs (0.43 kg)
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Operating Temperature: 0–60 °C (32–140 °F)
Key Features
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High-speed ControlNet communication for large-scale PLC systems
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Supports redundant network configurations for critical applications
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Backplane-compatible with all standard ControlLogix chassis
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Low power consumption with efficient thermal management
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Provides two ControlNet ports plus one USB port for flexible connectivity
Applications
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Network bridge for ControlNet PLC systems
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Integration of multiple ControlLogix modules in manufacturing and process control
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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.
Additional Information
- 100% Genuine Parts: All products are original and authentic, ensuring reliable industrial performance.
- 30-Day Refund Guarantee: Return any in-stock item within 30 days in original, unopened packaging for a full refund (excluding shipping and fees).
- 12-Month Warranty: Covers defects in materials or workmanship; excludes misuse, normal wear, or unauthorized modifications.
- Worldwide Shipping: We ship via USPS, UPS, FedEx, and DHL. Delivery times vary by country and may be subject to customs or import fees.
- Support & Contact: Technical and warranty assistance is available anytime. Contact us here: Contact.
- Purchase Guidance: Check product specifications and compatibility carefully before ordering to ensure proper application.
Tech & Buying Guide
Understanding Root Causes of Unplanned PLC Stop Mode in Industrial Automation
Modern Programmable Logic Controllers manage execution through distinct operational states: Run, Stop, Start-Up, and Hold. During power-up, a controller initializes memory registers within Stop mode before briefly transitioning to Start-Up mode. During this phase, internal self-diagnostics evaluate system integrity across hardware and user programs. If the controller detects no critical faults, it enters Run mode to execute the control program continuously. However, any severe system anomaly forces the CPU back into Stop mode immediately to prevent erratic machine behavior across the plant floor.
Human-Machine Interface Design: Essential Guide to HMI Selection, Visualization, and Control System Integration
Human-Machine Interfaces (HMIs) serve as the primary operational window into complex industrial automation systems. Modern HMIs convert raw machine data into clear graphical displays, enabling operators to oversee entire manufacturing processes in real time. Instead of relying on physical control panels full of hardwired switches, engineers program interactive screens using intuitive graphics, dynamic color coding, and responsive touch interfaces. Over my 15 years in control systems engineering, I have observed HMIs transform from basic display screens into sophisticated command centers that drive operational efficiency across DCS and PLC environments.
Understanding Safety Relays in Industrial Automation: Architecture, Operation, and Functional Safety
Standard electromechanical relays provide basic electrical isolation between low-voltage control circuits and high-power output loads. A traditional switching relay features a magnetic coil driving mechanical Common (COM), Normally-Open (NO), and Normally-Closed (NC) contacts. However, standard relays pose severe functional risks when deployed in critical safety interlock circuits. High current inrush or mechanical wear can weld contacts together permanently. If contact welding occurs in an emergency stop circuit, pressing the button fails to halt hazardous machinery movements. Consequently, global functional safety standards prohibit standard relays for critical machine guarding functions.