{"product_id":"allen-bradley-1756-cn2r-c-controllogix-controlnet-redundant-communication-module","title":"Allen-Bradley 1756-CN2R\/C ControlLogix ControlNet Redundant Communication Module","description":"\u003ch1 class=\"PDq2pG_selectionAnchorContainer\"\u003eAllen-Bradley 1756-CN2R\/C ControlLogix ControlNet Redundant Communication Module\u003cspan class=\"PDq2pG_selectionAnchor\"\u003e\u003c\/span\u003e\n\u003c\/h1\u003e\n\u003cp\u003eThe\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eAllen-Bradley 1756-CN2R\/C\u003c\/strong\u003e, also cataloged as the\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1756-CN2R\/C\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eControlLogix ControlNet redundant communication module, operates as a dedicated hardware interface for deterministic ControlNet data exchange and redundant A\/B channel network routing within ControlLogix backplane architectures. Configured for dual-channel ControlNet communication in ControlLogix systems, the\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1756-CN2R\/C\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eprovides direct physical transmission handling for up to 100 simultaneous network connections across redundant paths.\u003c\/p\u003e\n\u003cp\u003eManufactured under\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"hover:entity-accent entity-underline inline cursor-pointer align-baseline\"\u003eRockwell Automation\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003eControlLogix platform architecture, the module executes backplane-to-network protocol handling via ControlNet media, maintaining synchronized communication frames across redundant channels without galvanic separation between A and B paths.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003eSuffix Breakdown \u0026amp; Model Matrix\u003c\/h3\u003e\n\u003cp\u003eSingle configuration model. No documented functional suffix segmentation beyond catalog designation\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1756-CN2R\/C\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003ewithin ControlLogix ControlNet redundant communication module family.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003eHardware Specifications\u003c\/h3\u003e\n\u003ctable class=\"w-fit min-w-(--thread-content-width)\"\u003e\n\u003cthead\u003e\n\u003ctr class=\"firstRow\"\u003e\n\u003cth class=\"last:pe-10\"\u003eParameter\u003c\/th\u003e\n\u003cth class=\"last:pe-10\"\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003e1756-CN2R\/C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eAllen-Bradley\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOrigin\u003c\/td\u003e\n\u003ctd\u003eUSA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.5 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e5.1 cm x 22.9 cm x 17.8 cm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNetwork Type\u003c\/td\u003e\n\u003ctd\u003eControlNet redundant A\/B channels\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eConnections\u003c\/td\u003e\n\u003ctd\u003eUp to 100 simultaneous ControlNet connections\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIsolation\u003c\/td\u003e\n\u003ctd\u003e30 V continuous basic insulation (A\/B to backplane and inter-channel paths)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eElectromagnetic Immunity\u003c\/td\u003e\n\u003ctd\u003e10 V\/m (80–2000 MHz), 3 V\/m (2000–2700 MHz) compliance profile\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003chr\u003e\n\u003ch3\u003eControlNet Redundant Backplane Communication Architecture\u003c\/h3\u003e\n\u003cp\u003eThe 1756-CN2R\/C integrates into the ControlLogix backplane, where cyclic data is scheduled via deterministic ControlNet media access control. The module maintains dual-channel synchronization across A and B ControlNet segments, ensuring continuous frame-level alignment for redundancy switching without requiring external arbitration logic. Backplane-to-network throughput is managed through the ControlLogix internal communication scheduler, supporting multi-node distributed I\/O and controller interlocking structures.\u003c\/p\u003e\n\u003cp\u003eRedundancy handling is implemented at the network interface layer; both channels remain active, with real-time propagation of scheduled data packets across parallel media paths. Channel switching behavior is constrained by ControlNet scheduling integrity rather than application-layer intervention.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003eFrequently Asked Questions (FAQ)\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Does the 1756-CN2R\/C support hot-swap in ControlLogix chassis?\u003c\/strong\u003e\u003cbr\u003eA: Yes. The module supports removal and insertion under chassis power, provided ControlLogix system configuration allows module re-registration through Studio 5000 and network resynchronization is complete.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Is there galvanic isolation between ControlNet A and B channels?\u003c\/strong\u003e\u003cbr\u003eA: No. The A and B channels share basic insulation only; there is no galvanic isolation between redundant media paths.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: What limits apply to simultaneous ControlNet connections?\u003c\/strong\u003e\u003cbr\u003eA: The module supports up to 100 simultaneous ControlNet connections, constrained by network scheduling bandwidth and ControlLogix backplane communication capacity.\u003c\/p\u003e\n\u003chr\u003e\u003chr\u003e\n\u003ch3\u003eField Installation Guidelines\u003c\/h3\u003e\n\u003cp\u003eEnsure the module is inserted into a compatible ControlLogix chassis slot with proper backplane seating to maintain signal integrity across the communication interface. ControlNet coaxial cabling must follow standard impedance-matched routing practices, with consistent shielding continuity across trunk and drop segments.\u003c\/p\u003e\n\u003cp\u003eMaintain separation between ControlNet media and high-noise power conductors to reduce induced coupling. Shield grounding should be terminated at a single-point earth reference to prevent ground loop formation across redundant channels. Avoid sharp bending radii in coaxial runs to preserve impedance stability.\u003c\/p\u003e\n\u003cp\u003eChassis firmware and module revision compatibility must be verified prior to commissioning to ensure backplane scheduling consistency and network synchronization stability.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":43576186830938,"sku":"1756-CN2R\/C","price":123.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0612\/4601\/3530\/files\/1756-CN2RB1.jpg?v=1782872883","url":"https:\/\/www.plcmasters.com\/products\/allen-bradley-1756-cn2r-c-controllogix-controlnet-redundant-communication-module","provider":"PLC Masters Ltd.","version":"1.0","type":"link"}