{"product_id":"1756-ia8d-allen-bradley-controllogix-series-diagnostic-input-module","title":"1756-IA8D Allen-Bradley ControlLogix Series Diagnostic Input Module","description":"\u003cp\u003eThe \u003cstrong\u003eAllen-Bradley 1756-IA8D\u003c\/strong\u003e, also cataloged as the \u003cstrong\u003e1756-IA8D\u003c\/strong\u003e Diagnostic Input Module, operates as a dedicated hardware component for 120 VAC discrete signal sensing and wire-off fault detection within ControlLogix chassis control systems.\u003c\/p\u003e\n\u003ch3\u003eHardware Variant Structure\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1756-IA8D:\u003c\/strong\u003e Diagnostic 8-point 120 VAC discrete input module featuring point-level channel diagnostic detection and field-side fault reporting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1756-IA8:\u003c\/strong\u003e Standard non-diagnostic 8-point 120 VAC discrete input module base hardware revision.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eElectrical and Physical Specifications\u003c\/h3\u003e\n\u003cfigure\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\u003e1756-IA8D\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\u003eOrigin\u003c\/td\u003e\n\u003ctd\u003eUSA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Channels\u003c\/td\u003e\n\u003ctd\u003e8 Diagnostic Points\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNominal Input Voltage\u003c\/td\u003e\n\u003ctd\u003e120 VAC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Voltage Range\u003c\/td\u003e\n\u003ctd\u003e79 VAC to 132 VAC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Delay Time\u003c\/td\u003e\n\u003ctd\u003eProgrammable 9 ms or 18 ms\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMinimum Operating Current\u003c\/td\u003e\n\u003ctd\u003e5 mA at 79 VAC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Operating Current\u003c\/td\u003e\n\u003ctd\u003e16 mA at 132 VAC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Off-State Input Current\u003c\/td\u003e\n\u003ctd\u003e2.5 mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temp\u003c\/td\u003e\n\u003ctd\u003e0 deg C to +60 deg C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.35 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShipping Dimensions\u003c\/td\u003e\n\u003ctd\u003e23.3 x 17.5 x 5.3 cm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTariff Code\u003c\/td\u003e\n\u003ctd\u003e8537101190\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eDeterministic System Bus Integration\u003c\/h3\u003e\n\u003cp\u003eThe diagnostic input module transfers discrete field status bits directly across the 1756 backplane, maintaining high backplane bus communication velocity and optimized I\/O density scaling. Built-in firmware flash compatibility supports real-time fault flag reporting across EtherNet\/IP networks and ControlLogix PAC routines without compromising system scan cycles.\u003c\/p\u003e\n\u003ch3\u003eOrder Package Contents\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e1 x Allen-Bradley 1756-IA8D diagnostic input module\u003c\/li\u003e\n\u003cli\u003eAnti-static protective enclosure packaging\u003c\/li\u003e\n\u003cli\u003eMechanical keying tab kit for 1756 slot assignment\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eField Wiring and Installation Rules\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eTurn off main chassis power prior to seating or removing the module from the backplane.\u003c\/li\u003e\n\u003cli\u003eAlign board printed circuit guides with slot channels; press firmly until upper and lower retaining latches lock into position.\u003c\/li\u003e\n\u003cli\u003eWire 120 VAC field inputs to the removable terminal block (RTB) using appropriate wire gauge and crimp ferrules.\u003c\/li\u003e\n\u003cli\u003eSecure all cable shields to the local enclosure grounding bus bar using low-impedance grounding clamps.\u003c\/li\u003e\n\u003cli\u003eKeep 120 VAC field signal wiring isolated from low-voltage DC communication conductors.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eDiagnostic FAQ\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eWhat field voltage range is acceptable for valid on-state signals?\u003c\/p\u003e\n\u003cp\u003eThe channels operate reliably across an AC line voltage range of 79 VAC to 132 VAC.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eWhat programmable filter options exist for input signal conditioning?\u003c\/p\u003e\n\u003cp\u003eHardware hardware hardware filter delays can be configured via software to either 9 ms or 18 ms response profiles.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eDoes the card support Removal and Insertion Under Power (RIUP)?\u003c\/p\u003e\n\u003cp\u003eYes, the module supports RIUP under system power, though field wiring must be de-energized to prevent electrical hazards.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eWhat maximum current flows through each channel at 132 VAC?\u003c\/p\u003e\n\u003cp\u003eEach individual input point draws a maximum operating current of 16 mA when energized at 132 VAC.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eWhat off-state threshold leakage current is tolerated by the inputs?\u003c\/p\u003e\n\u003cp\u003eThe off-state input threshold allows a maximum leakage current limit of 2.5 mA per channel.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eWhat minimum current is needed for channel state detection at 79 VAC?\u003c\/p\u003e\n\u003cp\u003eAn absolute minimum input current of 5 mA at 79 VAC is required for positive logic state verification.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eHow are channel-level field wiring diagnostics reported to the controller?\u003c\/p\u003e\n\u003cp\u003eThe board monitors line continuity and raises diagnostic fault bits directly within the system I\/O image table.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eHow is physical slot keying established on the backplane connector?\u003c\/p\u003e\n\u003cp\u003ePosition configurable keying bands on the removable terminal block to match assigned slot positions on the chassis.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":46066413699245,"sku":"1756-IA8D","price":159.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0733\/1613\/9181\/files\/1756-IA8D.jpg?v=1786979962","url":"https:\/\/www.maxwellplc.com\/products\/1756-ia8d-allen-bradley-controllogix-series-diagnostic-input-module","provider":"Maxwell PLC Ltd","version":"1.0","type":"link"}