{"product_id":"allen-bradley-1794-ia8-flex-i-o-digital-input-module","title":"Allen-Bradley 1794-IA8 FLEX I\/O Digital Input Module","description":"\u003ch2\u003eAllen-Bradley 1794-IA8 FLEX I\/O Digital Input Module\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eAllen-Bradley 1794-IA8\u003c\/strong\u003e, also cataloged as the \u003cstrong\u003e1794-IA8\u003c\/strong\u003e Digital Input Module, operates as a dedicated hardware component for 120 V AC field signal acquisition within the Allen-Bradley FLEX I\/O system network. The module provides eight AC input channels with optical isolation between field wiring and backplane logic for PLC data processing.\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\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003e1794-IA8\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\u003eProduct Series\u003c\/td\u003e\n\u003ctd\u003eFLEX I\/O\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModule Type\u003c\/td\u003e\n\u003ctd\u003e120 V AC Digital Input Module\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOrigin\u003c\/td\u003e\n\u003ctd\u003eUnited States\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNumber of Inputs\u003c\/td\u003e\n\u003ctd\u003e8 digital AC inputs, 1 group\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Voltage\u003c\/td\u003e\n\u003ctd\u003e120 V AC nominal, 47-63 Hz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Voltage Range\u003c\/td\u003e\n\u003ctd\u003e65 V AC to 132 V AC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOn-state Voltage\u003c\/td\u003e\n\u003ctd\u003eMinimum 65 V AC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOff-state Voltage\u003c\/td\u003e\n\u003ctd\u003eMaximum 20 V AC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOn-state Current\u003c\/td\u003e\n\u003ctd\u003e12 mA at 120 V AC, 60 Hz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOff-state Current\u003c\/td\u003e\n\u003ctd\u003eMaximum 2.5 mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Impedance\u003c\/td\u003e\n\u003ctd\u003e10.6 kOhm nominal at 60 Hz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIsolation Voltage\u003c\/td\u003e\n\u003ctd\u003e1250 V AC for 60 seconds, inputs to bus\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFlexBus Current\u003c\/td\u003e\n\u003ctd\u003e30 mA at 5 V DC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Consumption\u003c\/td\u003e\n\u003ctd\u003e4.6 W maximum at 132 V AC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThermal Dissipation\u003c\/td\u003e\n\u003ctd\u003e15.7 BTU\/hr at 132 V AC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e46 x 94 x 53 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temp\u003c\/td\u003e\n\u003ctd\u003e0 deg C to 55 deg C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting Method\u003c\/td\u003e\n\u003ctd\u003eFLEX I\/O terminal base mounting\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eChannel Indicators\u003c\/td\u003e\n\u003ctd\u003e8 yellow LED status indicators\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eProfinet \/ EtherNet-IP Deterministic Network and FLEX I\/O Bus Integration\u003c\/h3\u003e\n\u003cp\u003eThe 1794-IA8 operates as a FLEX I\/O field interface module using the terminal base and adapter architecture of the FLEX I\/O platform. The module exchanges channel status information through the local FlexBus connection, with a specified backplane current requirement of 30 mA at 5 V DC. The I\/O density scaling capability allows multiple discrete input modules to be installed within a distributed control rack configuration.\u003c\/p\u003e\n\u003cp\u003eThe module supports Removal and Insertion Under Power (RIUP), allowing replacement of the module body while maintaining field wiring connections on the terminal base. Optical isolation separates AC field signals from internal bus electronics to limit electrical coupling between external devices and controller communication paths.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003eQ: Can the 1794-IA8 be replaced while the FLEX I\/O system remains energized?\u003cbr\u003eA: The module supports Removal and Insertion Under Power (RIUP). Field wiring remains connected through the terminal base during module replacement.\u003c\/p\u003e\n\u003cp\u003eQ: What type of input signals are processed by the 1794-IA8?\u003cbr\u003eA: The module accepts eight 120 V AC discrete input signals from field devices such as switches and contact devices.\u003c\/p\u003e\n\u003cp\u003eQ: How is electrical separation provided between field inputs and the control system bus?\u003cbr\u003eA: The module uses optocoupler isolation between input circuits and backplane logic, with isolation tested at 1250 V AC for 60 seconds.\u003c\/p\u003e\n\u003ch3\u003eField Installation Guidelines\u003c\/h3\u003e\n\u003cp\u003eInstall the 1794-IA8 on a compatible FLEX I\/O terminal base according to the system hardware configuration requirements. Verify that field voltage levels match the module input range before connection.\u003c\/p\u003e\n\u003cp\u003eMaintain separation between AC field wiring and low-level communication or signal wiring to reduce electrical interference. Connect cable shields according to the site grounding practice and avoid routing input wiring near high-current switching conductors.\u003c\/p\u003e\n\u003cp\u003eEnsure the terminal base is securely mounted and that field conductors are properly terminated before applying system power. Confirm LED channel indicators correspond with expected field device states during commissioning.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":43768134860890,"sku":"1794-IA8","price":123.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0612\/4601\/3530\/files\/1794-IA82.jpg?v=1785479693","url":"https:\/\/www.plcmasters.com\/products\/allen-bradley-1794-ia8-flex-i-o-digital-input-module","provider":"PLC Masters Ltd.","version":"1.0","type":"link"}