{"product_id":"allen-bradley-1794-ib8-flex-i-o-digital-input-module","title":"Allen-Bradley 1794-IB8 FLEX I\/O Digital Input Module","description":"\u003ch3\u003eDescription\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003e1794-IB8\u003c\/strong\u003e is a discrete hardware component engineered for the \u003cstrong\u003eFLEX I\/O\u003c\/strong\u003e distributed input\/output platform. This 24V DC digital input module is designed to monitor binary field conditions by converting high-level voltage potentials from industrial sensing devices into digital status bits for the system processor. Operating as a sinking configuration, the unit senses current passing from sourcing field elements through its input circuitry to the common return rail, establishing a clean interface between physical plant switches and digital logic registers.\u003c\/p\u003e\n\u003cp\u003eEquipped with eight independent, non-isolated input channels, the device routes field signals back to a centralized programmable logic controller via a compatible \u003cstrong\u003eFLEX I\/O\u003c\/strong\u003e network adapter across \u003cstrong\u003eEtherNet\/IP\u003c\/strong\u003e, \u003cstrong\u003eControlNet\u003c\/strong\u003e, or \u003cstrong\u003eDeviceNet\u003c\/strong\u003e backplanes. The \u003cstrong\u003e1794-IB8\u003c\/strong\u003e plugs directly into a specialized terminal base unit that anchors the module to standard industrial mounting frameworks. This module type is typically integrated into manufacturing applications, material handling facilities, logistics sorting hubs, and water infrastructure management panels requiring low-channel-count, reliable sensor aggregation.\u003c\/p\u003e\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEight discrete sinking input channels for low-density distributed field monitoring.\u003c\/li\u003e\n\u003cli\u003e24V DC nominal operation matching standard industrial proximity sensors and switches.\u003c\/li\u003e\n\u003cli\u003eSupport for Removal and Insertion Under Power (RIUP) to facilitate rapid maintenance cycles.\u003c\/li\u003e\n\u003cli\u003eIndividual front-facing LED indicators displaying real-time digital status for each input loop.\u003c\/li\u003e\n\u003cli\u003eIntegrated software filtering configurations to reduce signal bounce from mechanical contacts.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eApplications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eProximity sensor and photoelectric eye array state tracking.\u003c\/li\u003e\n\u003cli\u003ePushbutton stations and selector switch monitoring.\u003c\/li\u003e\n\u003cli\u003eConveyor line jam switch and sorting gate alignment verification.\u003c\/li\u003e\n\u003cli\u003eMechanical limit switch safety interlock logging.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eTechnical 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\u003eManufacturer\u003c\/td\u003e\n\u003ctd\u003eRockwell Automation \/ Allen-Bradley\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eFLEX I\/O\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePart Number\u003c\/td\u003e\n\u003ctd\u003e1794-IB8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModule Type\u003c\/td\u003e\n\u003ctd\u003eDigital Sinking Input Module\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNumber of Inputs\u003c\/td\u003e\n\u003ctd\u003e8 Channels, Non-Isolated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNominal Input Voltage\u003c\/td\u003e\n\u003ctd\u003e24V DC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOn-State Voltage Range\u003c\/td\u003e\n\u003ctd\u003e10V DC to 31.2V DC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOn-State Current Limit\u003c\/td\u003e\n\u003ctd\u003e2.0 mA minimum, 12.0 mA maximum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOff-State Voltage Range\u003c\/td\u003e\n\u003ctd\u003e5.0V DC maximum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOff-State Current Limit\u003c\/td\u003e\n\u003ctd\u003e1.5 mA maximum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Impedance\u003c\/td\u003e\n\u003ctd\u003e3.4 kilohms maximum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFlexBus Current Draw\u003c\/td\u003e\n\u003ctd\u003e30 mA at 5V DC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Filter Time (On to Off)\u003c\/td\u003e\n\u003ctd\u003eProgrammable (0.25 ms nominal to 8.0 ms maximum)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temperature\u003c\/td\u003e\n\u003ctd\u003e0 to 55 degC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStorage Temperature\u003c\/td\u003e\n\u003ctd\u003e-40 to 85 degC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRelative Humidity\u003c\/td\u003e\n\u003ctd\u003e5% to 95% non-condensing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCountry of Origin\u003c\/td\u003e\n\u003ctd\u003eUSA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.08 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e46 mm x 94 mm x 53 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eConnections\/Interfaces\u003c\/h3\u003e\n\u003cfigure class=\"table\"\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eTerminal Base Pin Location\u003c\/strong\u003e\u003c\/th\u003e\n\u003cth\u003e\u003cstrong\u003eFunction \/ Signal Assignment\u003c\/strong\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eTerminal 0 to Terminal 7\u003c\/td\u003e\n\u003ctd\u003eInput Signal Connection Nodes 0 through 7\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e+V (External Power)\u003c\/td\u003e\n\u003ctd\u003e24V DC Sourcing Sensor Voltage Supply Terminal\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCOM (External Power)\u003c\/td\u003e\n\u003ctd\u003eShared DC Return Reference Connection\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eInstallation Guidelines\u003c\/h3\u003e\n\u003ch3\u003eDIN Rail Installation\u003c\/h3\u003e\n\u003cp\u003eHook the upper retention slots of the enclosure chassis over the top flange of standard 35 mm DIN tracking. Rotate the lower portion of the housing down until the spring-loaded lower locking mechanisms snap firmly around the base metal rail.\u003c\/p\u003e\n\u003ch3\u003eTerminal Base Seating\u003c\/h3\u003e\n\u003cp\u003eAlign the molded structural alignment channels on the underside of the electronic module with the guide rails on the pre-installed terminal base unit. Push the module directly into the socket until the edge latches click to secure the unit.\u003c\/p\u003e\n\u003ch3\u003eWiring Configuration\u003c\/h3\u003e\n\u003cp\u003eConnect external sourcing sensors to terminals 0 through 7. Ensure that the 24V DC external operational voltage loop supplies field devices from the corresponding power rail on the terminal block to maintain a proper common return path.\u003c\/p\u003e\n\u003ch3\u003eSignal Integrity and Routing\u003c\/h3\u003e\n\u003cp\u003eIsolate the low-voltage direct current input lines from high-voltage AC electrical lines, electric motor feeds, and inductive switching fields to prevent ambient electromagnetic noise from generating false input transitions.\u003c\/p\u003e\n\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the electrical switching configuration of this module?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe module uses a sinking configuration, which requires connected field devices to source current into the input terminal.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAre individual input channels electrically isolated from each other?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo, the eight input channels share a common internal ground reference rail within the module assembly.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan an engineer hot-swap this device during active plant operation?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYes, it supports removal and insertion under power, allowing for module replacement without shutting down power to the wider assembly.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat terminal base models can be used to mount this unit?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eIt is compatible with standard terminal base assemblies including the 1794-TB2, 1794-TB3, 1794-TB3S, and 1794-TBN units.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow can high-frequency signal bounce from a mechanical switch be prevented?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe digital input filter time can be adjusted in the controller configuration parameters to stabilize noisy field signals.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat do the yellow LED indicators on the faceplate signify?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eEach indicator lights up when the corresponding input channel senses an active on-state voltage parameter.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes the module require external power to operate?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYes, a nominal 24V DC power source must be run to the terminal base block to drive the internal field-side input circuitry.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat voltage constitutes a logical off-state for a channel?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eAn input channel registers as off when the voltage potential drops below 5.0V DC or the input loop current falls below 1.5 mA.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan this device process signals from 120V AC limit switches?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo, this module is rated exclusively for low-voltage direct current ranges between 10V DC and 31.2V DC.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow is input data sent from this module to a ControlLogix processor?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe unit transmits register values across the local FlexBus backplane to a network adapter module, which then forwards the data to the central controller.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":52695186801003,"sku":"1794-IB8","price":100.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0953\/3227\/0443\/files\/allen-bradley-1794-ib8-flex-i-o-digital-input-modules-fb1zorbaqwg_6706dc9f-3245-4e71-98d3-ef243128a1a8.jpg?v=1766114485","url":"https:\/\/www.plcprotech.com\/hu\/products\/allen-bradley-1794-ib8-flex-i-o-digital-input-module","provider":"PLC ProTech Ltd.","version":"1.0","type":"link"}