{"product_id":"allen-bradley-1746-ib8-slc-500-digital-dc-input-module","title":"Allen-Bradley 1746-IB8 SLC 500 Digital DC Input Module","description":"\u003ch1\u003eAllen-Bradley 1746-IB8 SLC 500 Digital DC Input Module\u003c\/h1\u003e\n\u003cp\u003eConfigured for DC signal acquisition in SLC 500 backplane scanning cycles, the\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eAllen-Bradley 1746-IB8\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e(\u003cstrong\u003e1746-IB8\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eDigital DC Input Module) provides direct electrical conversion of 24 VDC sinking field signals into 8-channel discrete input states within the SLC 500 controller I\/O structure.\u003c\/p\u003e\n\u003cp\u003eThe module processes 10–30 VDC input signals with defined sink current behavior and transfers logic states through the backplane at fixed scan intervals. Input conditioning supports standard DC switching devices including pushbuttons and relay contacts with controlled response timing.\u003c\/p\u003e\n\u003ch3\u003eSuffix Breakdown \u0026amp; Model Matrix\u003c\/h3\u003e\n\u003cp\u003eNo structured suffix segmentation is defined for 1746-IB8. The model designation represents a fixed catalog identifier within the SLC 500 digital input module family.\u003c\/p\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\u003e1746-IB8\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\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.35 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Consumption\u003c\/td\u003e\n\u003ctd\u003e1.9 W (module dissipation)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Channels\u003c\/td\u003e\n\u003ctd\u003e8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVoltage Range\u003c\/td\u003e\n\u003ctd\u003e10–30 VDC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Type\u003c\/td\u003e\n\u003ctd\u003eSinking\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNominal Input Current\u003c\/td\u003e\n\u003ctd\u003e8 mA @ 24 VDC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBackplane Current\u003c\/td\u003e\n\u003ctd\u003e50 mA @ 5 VDC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOFF-State Current\u003c\/td\u003e\n\u003ctd\u003e1 mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSignal Delay\u003c\/td\u003e\n\u003ctd\u003e8 ms\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStep Response\u003c\/td\u003e\n\u003ctd\u003e100 ms ON \/ 2.5 ms OFF\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eI\/O Connection\u003c\/td\u003e\n\u003ctd\u003e1746-HT \/ 1746-HCA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHazard Classification\u003c\/td\u003e\n\u003ctd\u003eClass 1 Div 2 Groups A–D\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eSLC 500 Backplane Communication and Scan Behavior\u003c\/h3\u003e\n\u003cp\u003eThe module exchanges discrete input states through the SLC 500 backplane bus during cyclic controller scan execution. Data mapping is fixed per 8-point structure with no configurable scaling or filtering layers. Backplane current draw remains constant at 50 mA @ 5 VDC independent of input switching activity.\u003c\/p\u003e\n\u003ch3\u003eDC Sinking Input Circuit Behavior\u003c\/h3\u003e\n\u003cp\u003eInput channels are configured as sinking inputs with internal current path referencing the module common. The 10–30 VDC input range ensures compatibility with standard industrial DC switching devices. OFF-state discrimination is defined at 1 mA leakage threshold to prevent false triggering under residual voltage conditions.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions (FAQ)\u003c\/h3\u003e\n\u003cp\u003eQ: Does the 1746-IB8 support hot-swapping in an energized SLC 500 chassis?\u003cbr\u003eA: No. Module insertion or removal must be performed with backplane power removed to avoid data corruption or electrical transient stress.\u003c\/p\u003e\n\u003cp\u003eQ: What is the effect of all 8 channels switching simultaneously on backplane load?\u003cbr\u003eA: Backplane current remains constant at 50 mA @ 5 VDC regardless of channel state transitions.\u003c\/p\u003e\n\u003cp\u003eQ: Can firmware updates modify input behavior?\u003cbr\u003eA: No firmware layer exists. Input processing is hardware-defined through fixed backplane scan logic.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003eField Installation Guidelines\u003c\/h3\u003e\n\u003cp\u003eThe module shall be installed in a compatible SLC 500 chassis with correct backplane alignment before energization. Terminal wiring must follow sinking input configuration rules with proper reference common routing.\u003c\/p\u003e\n\u003cp\u003eSignal cables should be separated from high-voltage AC or high-frequency conductors to reduce induced coupling. Shield termination should follow single-point grounding practice at panel earth reference. Power isolation is required during module replacement to maintain backplane stability and prevent scan data corruption.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":43504103817306,"sku":"1746-IB8","price":123.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0612\/4601\/3530\/files\/1746-IB82.jpg?v=1781582446","url":"https:\/\/www.plcmasters.com\/products\/allen-bradley-1746-ib8-slc-500-digital-dc-input-module","provider":"PLC Masters Ltd.","version":"1.0","type":"link"}