{"product_id":"1756-ob8-allen-bradley-controllogix-digital-output-module-8-point-24v-dc","title":"1756-OB8 Allen-Bradley ControlLogix Digital Output Module | 8-Point 24V DC","description":"\u003ch3\u003eEngineering Overview\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003e1756-OB8\u003c\/strong\u003e is a high-performance discrete output module engineered by \u003cstrong\u003eAllen-Bradley\u003c\/strong\u003e for the \u003cstrong\u003eControlLogix\u003c\/strong\u003e architecture. Plant automation specialists deploy the \u003cstrong\u003e1756-OB8\u003c\/strong\u003e to switch and energize DC-powered industrial actuators, solenoid valves, and pilot-duty indicators across demanding manufacturing environments.\u003c\/p\u003e\n\u003ch3\u003eTechnical Specifications \u0026amp; Core Metrics\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer:\u003c\/strong\u003e Allen-Bradley \/ Rockwell Automation\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeries:\u003c\/strong\u003e \u003ca href=\"https:\/\/www.plcsparehub.com\/collections\/allen-bradley-1756-controllogix\"\u003eControlLogix\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eModule Type:\u003c\/strong\u003e \u003cstrong\u003e1756-OB8\u003c\/strong\u003e Digital DC Output Module\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNumber of Outputs:\u003c\/strong\u003e 8 points arranged in 2 isolated groups of 4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNominal Output Voltage:\u003c\/strong\u003e 24V DC Source\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOperating Voltage Range:\u003c\/strong\u003e 10 to 30V DC\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCurrent Rating per Point:\u003c\/strong\u003e 2 A max at 60°C (140°F)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCurrent Rating per Module:\u003c\/strong\u003e 8 A max at 60°C (140°F)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSignal Switching Speed:\u003c\/strong\u003e 1 ms max ON transition, 2 ms max OFF transition\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBackplane Power Consumption:\u003c\/strong\u003e 0.89 W total (165 mA at 5.1V DC, 2 mA at 24V DC)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePower Dissipation:\u003c\/strong\u003e 2.5 W max at 60°C\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompatible Removable Terminal Blocks (RTB):\u003c\/strong\u003e 1756-TBNH and 1756-TBSH (20-pin)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eEnvironmental Specifications \u0026amp; Operating Limits\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eOperating Ambient Temperature:\u003c\/strong\u003e 0°C to 60°C (32°F to 140°F)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStorage Temperature:\u003c\/strong\u003e -40°C to 85°C (-40°F to 185°F)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRelative Humidity:\u003c\/strong\u003e 5% to 95% non-condensing\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eContinuous Isolation Voltage:\u003c\/strong\u003e 250V isolation rating\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eConfiguration \u0026amp; System Integration Framework\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSlot Placement:\u003c\/strong\u003e Occupies any single available chassis slot except the leftmost processor or communication slot.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCommunication Formats:\u003c\/strong\u003e Supports rack optimization, listen-only rack optimization, output data, listen-only output data, and scheduled output data.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProgrammable Fault States:\u003c\/strong\u003e Configurable per-point behavior during fault or program mode (Hold Last State, On, or Off).\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFulfillment, Packaging \u0026amp; Warranty Terms\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCondition:\u003c\/strong\u003e Brand New \u0026amp; Original in Factory Packing\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFactory Warranty:\u003c\/strong\u003e Comprehensive 12-Month Coverage\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cstrong\u003eLogistics \u0026amp; Dispatch:\u003c\/strong\u003e Rapid 24-48 hour fulfillment via FedEx, UPS, and DHL\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eEquipment Compatibility \u0026amp; Industrial Application Scenarios\u003c\/h3\u003e\n\u003cp\u003eAutomation engineers integrate the \u003cstrong\u003e1756-OB8\u003c\/strong\u003e into large-scale distributed control setups, material handling systems, and automated assembly lines. Typical application targets include driving multi-stage pneumatic valve manifolds, heavy industrial relay coils, and optical signaling towers.\u003c\/p\u003e\n\u003ch3\u003eDiagnostic Capabilities \u0026amp; System Insight\u003c\/h3\u003e\n\u003cp\u003eThe module's built-in status reporting allows control systems to track point-level execution and verify load continuity. Plant technicians rely on these diagnostics to catch off-state leakage currents exceeding 1 mA or flag thermal overloads before unexpected line stoppages occur.\u003c\/p\u003e\n\u003ch3\u003eGlobal PLC Spare HUB Review\u003c\/h3\u003e\n\u003cp\u003eGlobal PLC Spare HUB's Insight confirms that utilizing authentic \u003cstrong\u003e1756-OB8\u003c\/strong\u003e hardware prevents backplane voltage drop anomalies often triggered by substandard third-party replacement cards. Rigorous pre-shipment bench testing ensures each unit meets Rockwell's precise switching threshold criteria.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions (FAQ)\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eQ: What selection criteria should engineers follow when choosing between the 1756-OB8 and high-density output modules?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: Choose the \u003cstrong\u003e1756-OB8\u003c\/strong\u003e when individual channel current loads reach up to 2 Amps, as high-density cards typically restrict per-point current capacity significantly.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: How does Global PLC Spare HUB ensure the structural integrity of the 1756-OB8 prior to dispatch?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: Global PLC Spare HUB's Insight verifies pin alignment, backplane communication handshake response, and thermal dissipation metrics under load simulation.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: What wiring practice prevents inductive kickback from damaging the 1756-OB8 transistor outputs?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: Always install flyback diodes across DC inductive loads like solenoid coils to suppress high-voltage transient spikes during the OFF transition.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Why is proper RTB keying essential when installing the 1756-OB8 into a live chassis?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: User-defined mechanical keying on the 1756-TBNH or 1756-TBSH terminal block prevents accidental insertion into mismatched voltage slots, safeguarding field wiring.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: What troubleshooting step resolves intermittent output dropouts on a single 1756-OB8 channel?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: Inspect the 20-pin removable terminal block wiring for loose screw terminations and verify that the module's maximum point current of 2 A is not being exceeded.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":45013910782134,"sku":"1756-OB8","price":143.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0722\/7863\/8774\/files\/1756-OB8.jpg?v=1787122676","url":"https:\/\/www.plcsparehub.com\/products\/1756-ob8-allen-bradley-controllogix-digital-output-module-8-point-24v-dc","provider":"Global PLC Spare Hub","version":"1.0","type":"link"}