{"product_id":"1756-cnb-allen-bradley-controllogix-controlnet-bridge-module-in-stock","title":"1756-CNB Allen-Bradley ControlLogix ControlNet Bridge Module | In Stock","description":"\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003eTechnical Specifications (MECE Framework)\u003c\/strong\u003e\u003c\/h3\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003e1. Basic System Identification\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer:\u003c\/strong\u003e \u003cstrong\u003e\u003cspan style=\"color: #d9534f;\"\u003eAllen-Bradley\u003c\/span\u003e\u003c\/strong\u003e \/ Rockwell Automation\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eModel \/ Catalog Number:\u003c\/strong\u003e \u003cstrong\u003e\u003cspan style=\"color: #0275d8;\"\u003e1756-CNB\u003c\/span\u003e\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Series:\u003c\/strong\u003e \u003ca href=\"https:\/\/www.plcsparehub.com\/collections\/allen-bradley-1756-controllogix\"\u003e\u003cstrong\u003e\u003cspan style=\"color: #0275d8;\"\u003eControlLogix\u003c\/span\u003e\u003c\/strong\u003e\u003c\/a\u003e System\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eModule Type:\u003c\/strong\u003e ControlNet Bridge Communication Module\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSlot Width Requirement:\u003c\/strong\u003e 1 Single Chassis Slot\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC Code:\u003c\/strong\u003e 10612598174079\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003e2. Network Performance \u0026amp; Electrical Data\u003c\/strong\u003e\u003c\/h3\u003e\n\u003ctable border=\"1\" cellpadding=\"8\" cellspacing=\"0\" style=\"border-collapse: collapse; width: 100%;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background-color: #f2f2f2;\"\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eTechnical Specification Standard\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBaud Rate\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e5 Megabits per second (Mbps) deterministic data rate\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMaximum Supported Nodes\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUp to 99 physical nodes per ControlNet link segment\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eConnection Capacity\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e64 bidirectional connections (mix of scheduled and unscheduled)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eUnconnected Message Buffers\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUp to 20 internal buffers allocated for non-scheduled messages\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003ePhysical Interface Options\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e1x BNC coaxial port (non-redundant) + 1x RJ-45 Network Access Port (NAP)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBackplane Current Draw (5.1V)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e970 mA at 5.1 VDC backplane supply logic bus\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBackplane Current Draw (24V)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e1.7 mA at 24 VDC auxiliary power line\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eTotal Power Dissipation\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e5.1 Watts operational power draw\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eThermal Dissipation Rate\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e17.4 BTU per hour heat release\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003e3. Hardware Addressing \u0026amp; Multi-Vendor Interoperability\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eNode Address Selection:\u003c\/strong\u003e Dual hardware rotary switches setting unique node addresses from 01 to 99.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePlatform Compatibility:\u003c\/strong\u003e Interoperates with Flex I\/O, POINT I\/O, SLC 500 ControlNet cards, PLC-5 ControlNet nodes, and industrial HMIs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCommunication Modes:\u003c\/strong\u003e Supports produced\/consumed tags, scheduled I\/O traffic, unscheduled CIP messaging, and remote engineering upload\/download.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003e4. Physical Properties \u0026amp; Environmental Specs\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.26 kg (0.57 lbs).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChassis Location:\u003c\/strong\u003e Any available slot in local or remote 1756 ControlLogix chassis.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003eSystem Diagnostics \u0026amp; Onboard Monitoring Capabilities\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003e\u003cspan style=\"color: #0275d8;\"\u003e1756-CNB\u003c\/span\u003e\u003c\/strong\u003e includes an active alphanumeric display on its front panel. The display cycles continuously through real-time operational metrics, including module catalog name, node address setting, network status, and active connection errors. Self-diagnostics communicate backplane health registers directly to Studio 5000 \/ RSLogix 5000 software, allowing engineers to audit packet retry counts, buffer usage, and media drop errors via the backplane interface.\u003c\/p\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003eTarget Machinery \u0026amp; Application Scenarios\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eLinking distributed \u003cstrong\u003e\u003cspan style=\"color: #0275d8;\"\u003eControlLogix\u003c\/span\u003e\u003c\/strong\u003e remote I\/O chassis across large manufacturing facilities.\u003c\/li\u003e\n\u003cli\u003eHigh-speed peer-to-peer data exchange between multiple Logix controllers using produced\/consumed tags.\u003c\/li\u003e\n\u003cli\u003eInterfacing legacy ControlNet platforms (PLC-5\/ControlNet, SLC 500) to modern ControlLogix networks.\u003c\/li\u003e\n\u003cli\u003eConnecting SCADA server nodes, panel display HMIs, and programming stations via the front NAP port.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003eInstallation \u0026amp; Wiring Guidelines\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eSet the hardware rotary switches on the side of the \u003cstrong\u003e\u003cspan style=\"color: #0275d8;\"\u003e1756-CNB\u003c\/span\u003e\u003c\/strong\u003e to an unassigned node address (01 to 99) prior to chassis insertion. Insert the unit into any slot of the 1756 chassis until the top and bottom latches click into place. Connect RG-6 quad-shield coaxial cable with standard BNC connectors to the front ControlNet port. Torque coaxial connections properly to avoid signal reflection, and route communication cabling away from high-voltage AC motor drives to minimize EMI exposure.\u003c\/p\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003ePackaging, Logistics \u0026amp; Warranty Terms\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Contents:\u003c\/strong\u003e 1x Genuine \u003cstrong\u003e\u003cspan style=\"color: #d9534f;\"\u003eAllen-Bradley\u003c\/span\u003e \u003cspan style=\"color: #0275d8;\"\u003e1756-CNB\u003c\/span\u003e\u003c\/strong\u003e ControlNet Bridge Unit, Technical Installation Leaflet.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty Terms:\u003c\/strong\u003e Standard 12-month comprehensive replacement warranty against operational defects.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOrder Handling:\u003c\/strong\u003e Fast warehouse processing with 24 to 48 hour dispatch.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGlobal Carriers:\u003c\/strong\u003e Worldwide express delivery managed via FedEx, UPS, or DHL.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003eGlobal PLC Spare HUB's Insight \u0026amp; Field Experience\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eDuring a network commissioning project in an automotive stamping plant, our field engineers encountered recurring dropouts on a ControlNet drop driven by a \u003cstrong\u003e\u003cspan style=\"color: #0275d8;\"\u003e1756-CNB\u003c\/span\u003e\u003c\/strong\u003e bridge module. System logs showed intermittent connection timeouts whenever a nearby welding robot cycled. Connecting a network analyzer via the front RJ-45 NAP port revealed high media jitter caused by a loose BNC tap connector on the coaxial trunk line. Tightening the BNC connector and verifying trunk termination resistors immediately restored full 5 Mbps scheduled packet delivery. \u003cem\u003eField Tip: Always inspect BNC tap connections and verify 75-ohm trunk terminations at both ends of the ControlNet cable segment when troubleshooting packet retry errors.\u003c\/em\u003e\u003c\/p\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003eSelection \u0026amp; Buyer's Guide\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eBefore ordering the \u003cstrong\u003e\u003cspan style=\"color: #0275d8;\"\u003e1756-CNB\u003c\/span\u003e\u003c\/strong\u003e, confirm whether your network architecture requires media redundancy. The single-BNC port on the \u003cstrong\u003e\u003cspan style=\"color: #0275d8;\"\u003e1756-CNB\u003c\/span\u003e\u003c\/strong\u003e is designed for standard non-redundant installations; if your application demands dual-path media redundancy, select the 1756-CNBR variant instead. Furthermore, calculate your connection load: a single \u003cstrong\u003e\u003cspan style=\"color: #0275d8;\"\u003e1756-CNB\u003c\/span\u003e\u003c\/strong\u003e handles up to 64 connections. If your architecture demands more concurrent scheduled\/unscheduled paths, install a second bridge module within the same chassis backplane.\u003c\/p\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003eFrequently Asked Questions (FAQ)\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eQ1: What is the primary operational difference between the 1756-CNB and 1756-CNBR modules?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: The 1756-CNB features a single BNC port for non-redundant media networks, whereas the 1756-CNBR includes dual BNC connectors to support redundant media cabling paths.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ2: How do I access local network diagnostics without disconnecting the main BNC cable?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: Connect a diagnostic laptop using a compatible interface cable directly to the front-panel RJ-45 Network Access Port (NAP) to inspect network parameters without disrupting BNC traffic.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ3: What steps are required when replacing an existing 1756-CNB module in a live chassis?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: Set the rotary switches on the replacement unit to match the exact node address of the removed module before inserting it into the backplane, ensuring seamless network reintegration.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ4: Why does the front-panel display scroll diagnostic text messages during normal operation?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: The rolling LED text is normal hardware behavior that provides real-time status, showing the module catalog name, assigned node number, and active connection state for fast field checks.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ5: What happens if an application exceeds the 64 connection capacity limit of the module?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: Connection requests above 64 will be rejected by the module; resolve this by optimizing schedule NUT (Network Update Time) settings or adding an additional bridge module in the chassis.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":45013808513206,"sku":"1756-CNB","price":163.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0722\/7863\/8774\/files\/1756-CNB2-3.jpg?v=1789373136","url":"https:\/\/www.plcsparehub.com\/products\/1756-cnb-allen-bradley-controllogix-controlnet-bridge-module-in-stock","provider":"Global PLC Spare Hub","version":"1.0","type":"link"}