{"product_id":"allen-bradley-1786-xt-controlnet-coaxial-trunk-terminator","title":"Allen-Bradley 1786-XT ControlNet Coaxial Trunk Terminator","description":"\u003ch2\u003eAllen-Bradley 1786-XT ControlNet Coaxial Trunk Terminator\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eAllen-Bradley 1786-XT\u003c\/strong\u003e, also cataloged as the \u003cstrong\u003e1786-XT\/A\u003c\/strong\u003e ControlNet coaxial terminating resistor, operates as a dedicated hardware component for 75 Ohm impedance matching and signal reflection suppression within ControlNet trunk line networks.\u003c\/p\u003e\n\u003ch3\u003eSuffix Breakdown \u0026amp; Model Matrix\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1786-XT\u003c\/strong\u003e: Standard 75 Ohm ControlNet coaxial trunk terminator utilizing standard industrial environmental specifications (-40 deg C to +85 deg C operating temperature).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1786-XT\/A\u003c\/strong\u003e: Series revision variant specifying strict ambient temperature handling protocols (0 deg C to +60 deg C operating temperature envelope).\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eHardware Specifications\u003c\/h3\u003e\n\u003cfigure class=\"table\"\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eParameter\u003c\/strong\u003e\u003c\/th\u003e\n\u003cth\u003e\u003cstrong\u003eSpecification\u003c\/strong\u003e\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\u003e1786-XT \/ 1786-XT\/A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eAllen-Bradley \/ Rockwell Automation\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\u003e0.04 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temp\u003c\/td\u003e\n\u003ctd\u003e-40 deg C to +85 deg C (Standard) \/ 0 deg C to +60 deg C (Series A)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Consumption\u003c\/td\u003e\n\u003ctd\u003ePassive (0 W)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNominal Impedance\u003c\/td\u003e\n\u003ctd\u003e75 Ohm +\/- 1% precision termination\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eConnector Type\u003c\/td\u003e\n\u003ctd\u003eBNC plug (male), nickel-plated brass body\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eContact Material\u003c\/td\u003e\n\u003ctd\u003eGold-plated center pin\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFrequency Range\u003c\/td\u003e\n\u003ctd\u003eDC to 5 MHz (ControlNet media spectrum)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatible Cable\u003c\/td\u003e\n\u003ctd\u003eRG-6 quad-shield coaxial cable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIngress Protection\u003c\/td\u003e\n\u003ctd\u003eIP20\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eDeterministic Network Trunk Impedance Termination\u003c\/h3\u003e\n\u003cp\u003eIn deterministic fieldbus architectures such as EtherNet\/IP and ControlNet, physical media termination prevents high-frequency data transmission corruption. The 1786-XT maintains constant 75 Ohm line load across the 5 MHz transmission frequency spectrum, attenuating signal reflection at both physical drop cable endpoints. Backplane bus communication stability depends directly on clean waveform propagation; un-terminated trunk nodes introduce standing waves that trigger frame cyclic redundancy check (CRC) failures, node dropouts, and backplane packet drop delays.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003eQ: Does the 1786-XT require external DC power or backplane current draw?\u003c\/p\u003e\n\u003cp\u003eA: No. The 1786-XT is a purely passive resistive component that draws 0 mA from the backplane or external supply, operating entirely via passive termination across the coaxial signal path.\u003c\/p\u003e\n\u003cp\u003eQ: Can standard 50 Ohm BNC terminators be substituted for the 1786-XT on a ControlNet network?\u003c\/p\u003e\n\u003cp\u003eA: No. ControlNet media topology strictly mandates 75 Ohm characteristic impedance. Inserting a 50 Ohm terminator causes a severe impedance mismatch, resulting in signal reflections, increased bit error rates, and network failure.\u003c\/p\u003e\n\u003ch3\u003eField Installation Guidelines\u003c\/h3\u003e\n\u003col\u003e\n\u003cli\u003eInstall exactly two 75 Ohm terminators per ControlNet coaxial segment, placing one unit directly on the unused port of the BNC T-connector at each physical end node of the trunk line.\u003c\/li\u003e\n\u003cli\u003eEnsure full 1\/4-turn bayonet lock engagement on the BNC plug to maintain low-resistance grounding contact between the shield and nickel-plated connector body.\u003c\/li\u003e\n\u003cli\u003eKeep coaxial cable run isolation compliant with standard industrial noise abatement practices, maintaining separation from high-voltage AC motor drives and field power conductors.\u003c\/li\u003e\n\u003c\/ol\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":43757418807386,"sku":"1786-XT","price":123.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0612\/4601\/3530\/files\/1786-XT2.jpg?v=1785314725","url":"https:\/\/www.plcmasters.com\/products\/allen-bradley-1786-xt-controlnet-coaxial-trunk-terminator","provider":"PLC Masters Ltd.","version":"1.0","type":"link"}