{"product_id":"allen-bradley-1746-ib8-digital-input-module","title":"Allen Bradley 1746‑IB8 Digital Input Module","description":"\u003ch2\u003eAllen‑Bradley 1746‑IB8 Digital Input Module\u003c\/h2\u003e\n\u003cp\u003eConfigured for discrete signal acquisition in SLC 500 architectures, the \u003cstrong\u003eAllen‑Bradley 1746‑IB8\u003c\/strong\u003e (\u003cstrong\u003e1746‑IB8\u003c\/strong\u003e digital input module) provides direct electrical execution of 24 VDC sinking input detection, backplane‑powered logic interfacing, and fixed‑delay state transitions.\u003c\/p\u003e\n\u003ch3\u003eHardware Specifications\u003c\/h3\u003e\n\u003cfigure class=\"table\"\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eModel\u003c\/strong\u003e\u003c\/th\u003e\n\u003ctd\u003e1746‑IB8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eBrand\u003c\/strong\u003e\u003c\/th\u003e\n\u003ctd\u003eAllen‑Bradley\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eOrigin\u003c\/strong\u003e\u003c\/th\u003e\n\u003ctd\u003eNot specified\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eWeight\u003c\/strong\u003e\u003c\/th\u003e\n\u003ctd\u003eNot specified\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eDimensions\u003c\/strong\u003e\u003c\/th\u003e\n\u003ctd\u003eNot specified\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eOperating Temp\u003c\/strong\u003e\u003c\/th\u003e\n\u003ctd\u003eNot specified\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003ePower Consumption\u003c\/strong\u003e\u003c\/th\u003e\n\u003ctd\u003e5 VDC at 0.050 A (backplane), 24 VDC at 0.0 A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eVoltage Category\u003c\/strong\u003e\u003c\/th\u003e\n\u003ctd\u003e24 VDC sinking inputs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eNumber of Inputs\u003c\/strong\u003e\u003c\/th\u003e\n\u003ctd\u003e8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003ePoints per Common\u003c\/strong\u003e\u003c\/th\u003e\n\u003ctd\u003e8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eOperating Voltage\u003c\/strong\u003e\u003c\/th\u003e\n\u003ctd\u003e10…30 VDC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eSignal Delay (max)\u003c\/strong\u003e\u003c\/th\u003e\n\u003ctd\u003eON = 8 ms, OFF = 8 ms\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eOff‑State Voltage (max)\u003c\/strong\u003e\u003c\/th\u003e\n\u003ctd\u003e5.0 VDC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eOff‑State Current (max)\u003c\/strong\u003e\u003c\/th\u003e\n\u003ctd\u003e1 mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eInput Current (nom)\u003c\/strong\u003e\u003c\/th\u003e\n\u003ctd\u003e8 mA @ 24 VDC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eBackplane Bus Communication Velocity and Firmware Compatibility\u003c\/h3\u003e\n\u003cp\u003eWithin SLC 500 platforms, the 1746‑IB8 participates in deterministic \u003cstrong\u003ebackplane bus communication\u003c\/strong\u003e, ensuring predictable input‑scan timing relative to the processor’s scan cycle. The module’s 50 mA load at 5 VDC contributes to overall \u003cstrong\u003eI\/O density scaling\u003c\/strong\u003e, requiring proper power‑budget allocation when multiple modules coexist. The 1746‑IB8 contains no user‑upgradeable firmware; compatibility is determined solely by the installed SLC processor revision.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Can the 1746‑IB8 be hot‑swapped in a powered SLC chassis\u003c\/strong\u003e A: No. The module should only be inserted or removed when the chassis is de‑energized to avoid backplane communication faults.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Does the module support sourcing inputs\u003c\/strong\u003e A: No. The 1746‑IB8 is designed exclusively for sinking input configurations.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: How do signal delays affect input recognition\u003c\/strong\u003e A: The fixed 8 ms ON\/OFF delay defines the minimum transition time required for reliable detection.\u003c\/p\u003e\n\u003ch3\u003eField Installation Guidelines\u003c\/h3\u003e\n\u003cp\u003eRoute 24 VDC input wiring separately from high‑voltage conductors to reduce noise coupling. Maintain proper terminal engagement and adhere to recommended conductor sizes. Ensure sinking input devices are wired with correct polarity to avoid false states. Verify backplane power capacity when installing multiple digital modules. Maintain non‑condensing humidity conditions to prevent terminal oxidation.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":43831410032714,"sku":"1746-IB8","price":230.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0587\/8569\/3770\/files\/1746-IB16_3.png?v=1784712704","url":"https:\/\/www.topbrandsplc.com\/products\/allen-bradley-1746-ib8-digital-input-module","provider":"Topbrands PLC Limited","version":"1.0","type":"link"}