{"product_id":"allen-bradley-1756-cn2r-b-controlnet-communication-module","title":"Allen-Bradley 1756-CN2R\/B ControlLogix ControlNet Redundant Communication Module","description":"\u003cp\u003eThe Allen-Bradley 1756-CN2R\/B is a Series B ControlNet communication bridge module engineered for the ControlLogix platform. This module provides deterministic, high-speed data exchange between controllers, I\/O, and field devices, featuring dual-channel redundancy to maintain network integrity during physical cable faults. As a critical component for ControlLogix architectures, it ensures reliable communication in demanding industrial environments.\u003c\/p\u003e\u003ch3\u003eFeatures\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eRedundant Communication:\u003c\/strong\u003e Supports dual-channel coaxial connections, allowing for automatic failover if a primary cable segment experiences a fault, ensuring continuous operation.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDeterministic Throughput:\u003c\/strong\u003e Maintains a steady 5 Mbps data rate, essential for time-critical control applications.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh Capacity:\u003c\/strong\u003e Manages up to 131 total connections, including 128 dedicated Logix connections, across a maximum of 99 network nodes.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIntegrated USB Port:\u003c\/strong\u003e Includes a local USB port for configuration and diagnostics at 12 Mbps speed.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeries B Hardware:\u003c\/strong\u003e Updated internal circuitry and firmware to improve reliability and performance within the ControlLogix backplane.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eApplications\u003c\/h3\u003e\u003cp\u003eThis module is widely utilized in large-scale automation systems requiring high-speed, deterministic data routing. It is suitable for distributed control systems, remote I\/O management, and complex machine integration where network downtime must be minimized through redundant media paths.\u003c\/p\u003e\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\u003ctable border=\"1\" style=\"border-collapse: collapse; width: 100%;\"\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003e1756-CN2R\/B\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSeries\u003c\/td\u003e\n\u003ctd\u003eSeries B\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunication Rate\u003c\/td\u003e\n\u003ctd\u003e5 Mbps (ControlNet) \/ 12 Mbps (USB)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBackplane Current (5.1V)\u003c\/td\u003e\n\u003ctd\u003e1300 mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Dissipation\u003c\/td\u003e\n\u003ctd\u003e6.7 Watts\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThermal Dissipation\u003c\/td\u003e\n\u003ctd\u003e22.9 BTU\/hr\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temp\u003c\/td\u003e\n\u003ctd\u003e0 to 60 deg C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSlot Width\u003c\/td\u003e\n\u003ctd\u003eSingle-slot\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch3\u003eInstallation Guidelines\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePower Off:\u003c\/strong\u003e Ensure the ControlLogix chassis is powered down before inserting or removing the module to prevent electrical damage.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eESD Precautions:\u003c\/strong\u003e Use an anti-static wrist strap or grounded work surface when handling the module to protect internal circuitry from electrostatic discharge.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeating:\u003c\/strong\u003e Ensure the module is properly aligned with the chassis guide rails and fully seated in the backplane connector before securing with the top\/bottom latching screws.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCabling:\u003c\/strong\u003e Use only 1786-RG6 quad-shield coaxial cable for ControlNet connections. Ensure BNC connectors are securely tightened to prevent signal degradation or impedance mismatches.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEnvironment:\u003c\/strong\u003e Install within an enclosure suitable for the application environment; ensure adequate airflow around the chassis to maintain operating temperatures below 60 deg C.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eDoes the 1756-CN2R\/B support redundant power supplies?\u003c\/strong\u003e Yes, the module is compatible with various ControlLogix redundant power supply systems including the 1756-PA75R and 1756-PB75R.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use this in any ControlLogix chassis?\u003c\/strong\u003e It is compatible with standard ControlLogix chassis such as the 1756-A4, A7, A10, A13, and A17 series.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat happens if one ControlNet cable is disconnected?\u003c\/strong\u003e The module features seamless media failover; if one channel fails, the communication traffic is automatically routed through the secondary channel without interrupting the processor's connection to the network.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":44052079771738,"sku":"1756-CN2R\/B","price":87.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0710\/5957\/0778\/files\/wm_1_9c2d5dc3-9988-4b05-8300-cc2a1819aee1.jpg?v=1789174766","url":"https:\/\/www.spareoil.com\/products\/allen-bradley-1756-cn2r-b-controlnet-communication-module","provider":"SpareOil Automation","version":"1.0","type":"link"}