{"product_id":"1794-acnr-redundant-controlnet-media-adapter-allen-bradley","title":"1794-ACNR Redundant ControlNet Media Adapter Allen-Bradley","description":"\u003ch3\u003e\u003cb\u003eProduct Overview\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong style=\"color: #0056b3;\"\u003e1794-ACNR\u003c\/strong\u003e is a DIN rail-mounted, dual-port ControlNet communication adapter manufactured by \u003cstrong style=\"color: #0056b3;\"\u003eAllen-Bradley\u003c\/strong\u003e for the \u003cstrong style=\"color: #0056b3;\"\u003eFLEX I\/O\u003c\/strong\u003e architecture. Designed to interface local distributed I\/O clusters with high-level PLC\/PAC host controllers, this redundant media module bridges field-level signals onto high-availability ControlNet coaxial data highways at transmission speeds of 5 Mbps.\u003c\/p\u003e\n\u003cp\u003eCapable of powering and backplane-managing up to 8 FLEX I\/O expansion modules, the \u003cstrong style=\"color: #0056b3;\"\u003e1794-ACNR\u003c\/strong\u003e delivers a maximum Flexbus output current of 640 mA @ 5 VDC. Featuring dual BNC connectors for media redundancy (Comm A and Comm B), the adapter ensures uninterrupted deterministic I\/O data transfer even in the event of a primary trunk cable severance or physical port failure.\u003c\/p\u003e\n\u003ch3\u003e\u003cb\u003eSystem Architecture \u0026amp; Communication Specs\u003c\/b\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cb\u003eDual-BNC Redundant Media Interface\u003c\/b\u003e\n\u003cul\u003e\n\u003cli\u003eEquipped with two independent BNC coaxial connectors for direct tap-in to redundant ControlNet trunks.\u003c\/li\u003e\n\u003cli\u003eAutomatic media health monitoring and seamless failover between Trunk A and Trunk B without dropping I\/O connections.\u003c\/li\u003e\n\u003cli\u003eFully compliant with ControlNet Protocol Version 1.25, supporting maximum data rates up to 5 Mbps over RG-6\/U coax cable.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eFlexbus Power \u0026amp; Expansion Capacity\u003c\/b\u003e\n\u003cul\u003e\n\u003cli\u003eDrives up to 8 discrete, analog, or specialty FLEX I\/O terminal base units per adapter node.\u003c\/li\u003e\n\u003cli\u003eProvides up to 640 mA backplane current at 5 VDC to power connected I\/O logic circuits.\u003c\/li\u003e\n\u003cli\u003eGalvanically isolated design featuring 850 VDC isolation withstand voltage for transient surge suppression.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003ePower Handling \u0026amp; Thermal Parameters\u003c\/b\u003e\n\u003cul\u003e\n\u003cli\u003eOperates off an external 24 VDC nominal supply (19.2 to 31.2 VDC input range, SELV\/PELV compliant).\u003c\/li\u003e\n\u003cli\u003eMaximum power dissipation limited to 4.6 W @ 19.2 VDC with a thermal output of 15.7 BTU\/hr.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cb\u003eTechnical Specifications\u003c\/b\u003e\u003c\/h3\u003e\n\u003ctable border=\"1\" cellpadding=\"8\" cellspacing=\"0\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003ePart Number\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong style=\"color: #0056b3;\"\u003e1794-ACNR\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eManufacturer \u0026amp; Brand\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003e\n\u003cstrong style=\"color: #0056b3;\"\u003eAllen-Bradley\u003c\/strong\u003e \/ Rockwell Automation\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eProduct Series\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003ca href=\"https:\/\/www.plcsparehub.com\/collections\/allen-bradley-1794-flex-i-o\"\u003e\u003cstrong style=\"color: #0056b3;\"\u003eFLEX I\/O\u003c\/strong\u003e Series\u003c\/a\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eModule Type\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003eRedundant ControlNet Communication Adapter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eCommunication Ports\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003e2 x ControlNet BNC Coaxial Ports (Comm A \/ Comm B)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eData Baud Rate\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003e5 Mbps Deterministic ControlNet Protocol\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eMaximum Expansion\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003eUp to 8 FLEX I\/O Terminal Base Units \/ Modules\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eFlexbus Output Current\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003e640 mA Maximum @ 5 VDC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eInput Power Supply\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003e24 VDC Nominal (19.2 to 31.2 VDC Range)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eInrush Current\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003e23 A for 2 Milliseconds Maximum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eOperating Temperature\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003e-20°C to +55°C (-4°F to +131°F)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eVibration \/ Shock Resistance\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003e5 g @ 10–500 Hz (Operating) \/ 30 g Shock\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eMounting Options\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003e35 mm DIN Rail or Direct Panel Mounting\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eDimensions \u0026amp; Enclosure\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003e94 x 91 x 86 mm (3.7 x 3.6 x 3.4 in) | Open Type\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003e\u003cb\u003eDiagnostic Capabilities \u0026amp; Front Panel Telemetry\u003c\/b\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cb\u003eDual Comm Status LEDs:\u003c\/b\u003e Independent bi-color (Red\/Green) indicators for Comm A and Comm B display network link integrity, packet loss, and channel fault states.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eI\/O Status LED:\u003c\/b\u003e Provides direct visual indication of Flexbus backplane communication, module configuration mismatches, and rack fault conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eControlNet Network Diagnostics:\u003c\/b\u003e Accessible via RSLogix \/ Studio 5000 environment to monitor media noise levels, duplicate node detection, and signal attenuation metrics.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cb\u003eTarget Application Scenarios \u0026amp; Automation Systems\u003c\/b\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cb\u003eContinuous Process Control:\u003c\/b\u003e Integrates remote FLEX I\/O racks in chemical processing units where network downtime is unacceptable.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eHigh-Availability PLC Architectures:\u003c\/b\u003e Interfaced with ControlLogix (1756-CN2R) or PLC-5 ControlNet scanner modules in dual-media configurations.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eVibration \u0026amp; Harsh Machinery Environments:\u003c\/b\u003e Rated for 5 g vibration and 30 g operating shock, suitable for heavy industrial skid mounting.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cb\u003eInstallation \u0026amp; Power Supply Guidelines\u003c\/b\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cb\u003ePower Supply Compliance:\u003c\/b\u003e Connect strictly to an isolated SELV or PELV 24 VDC power supply to ensure compliance with CE Low Voltage Directives.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eFlexbus Current Budgeting:\u003c\/b\u003e Calculate total 5 VDC current consumption across all 8 attached modules to ensure the total load does not exceed 640 mA.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eBNC Tap Cable Routing:\u003c\/b\u003e Maintain proper coaxial cable bending radii and ensure BNC coupling nuts are firmly locked to prevent signal reflection.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cb\u003ePackaging, Logistics \u0026amp; Warranty Terms\u003c\/b\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cb\u003eDispatch Lead Time:\u003c\/b\u003e Factory-sealed units in stock, ready for dispatch within 24 to 48 hours.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eGlobal Express Delivery:\u003c\/b\u003e Priority international shipping provided via FedEx, UPS, and DHL.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eQuality Assurance:\u003c\/b\u003e Delivered 100% Brand New and Original in sealed manufacturer packaging.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003e12-Month Coverage:\u003c\/b\u003e Backed by a full 12-month quality replacement warranty against operational defects.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cb\u003eEngineering Procurement Guide\u003c\/b\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cb\u003eVerify Coax Trunk Hardware:\u003c\/b\u003e Ensure BNC taps, trunk terminators (75-ohm), and Belden RG-6\/U cables meet ControlNet physical layer installation standards.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eConfirm Node Address Assignment:\u003c\/b\u003e Ensure the network address switches on the adapter are set correctly prior to mounting on the DIN rail.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eCalculate External Power Supply Capacity:\u003c\/b\u003e Budget for the 23 A for 2 ms inrush current characteristic during system cold boots.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cb\u003eFrequently Asked Questions (FAQ)\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cb\u003eQ: What occurs if Trunk A experiences a physical cable cut while the system is operating?\u003c\/b\u003e\u003c\/p\u003e\n\u003cp\u003eA: The adapter instantly flags Comm A as faulted and switches communication traffic to Trunk B without dropping backplane I\/O connections or halting the process controller.\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eQ: How do I determine if my 8 attached I\/O modules exceed the maximum Flexbus power limit?\u003c\/b\u003e\u003c\/p\u003e\n\u003cp\u003eA: Sum the 5V Flexbus current requirements listed in the data sheets for all 8 modules; the total must remain below the 640 mA output limit of the adapter.\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eQ: Can this communication module be installed in an outdoor cabinet without secondary enclosures?\u003c\/b\u003e\u003c\/p\u003e\n\u003cp\u003eA: No, the adapter features an open-type enclosure rating and must be mounted inside an IP54 or NEMA-rated protective industrial panel.\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eQ: What is the recommended procedure for setting the ControlNet node address on this device?\u003c\/b\u003e\u003c\/p\u003e\n\u003cp\u003eA: Use the rotary switches located on the module to select a unique network node number before applying power to the 24 VDC terminals.\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eQ: Are special grounding considerations required for the BNC network connections?\u003c\/b\u003e\u003c\/p\u003e\n\u003cp\u003eA: Yes, ControlNet taps must be properly grounded at specified single-point ground locations to prevent shield voltage buildup and signal distortion.\u003c\/p\u003e\n\u003ch3\u003e\u003cb\u003eGlobal PLC Spare HUB's Insight\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp\u003eDuring an emergency shutdown at an automotive stamping facility, maintenance engineers traced a recurring machine trip to a broken communication head on a remote FLEX I\/O rack. The legacy single-media adapter had suffered a physical BNC port fracture from high press vibration, cutting off all I\/O telemetry to the main PLC rack.\u003c\/p\u003e\n\u003cp\u003eOur engineering team recommended replacing the damaged unit with the \u003cstrong style=\"color: #0056b3;\"\u003e1794-ACNR\u003c\/strong\u003e dual-port redundant adapter. By wiring dual RG-6\/U coaxial cable runs to Comm A and Comm B and securing the assembly onto a reinforced DIN rail, the plant established full media redundancy. When minor cable wear occurred months later on line A, the card transferred communication seamlessly to line B, avoiding an estimated $45,000 in unplanned downtime.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":45013984051382,"sku":"1794-ACNR","price":117.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0722\/7863\/8774\/files\/1794-ACNR.jpg?v=1789025385","url":"https:\/\/www.plcsparehub.com\/products\/1794-acnr-redundant-controlnet-media-adapter-allen-bradley","provider":"Global PLC Spare Hub","version":"1.0","type":"link"}