{"product_id":"woodward-9905-971-linknet-discrete-input-module-24-channel-24vdc-control","title":"Woodward 9905-971 LINKNet Discrete Input Module | 24-Channel 24VDC Control","description":"\u003ch2\u003eProduct Overview\u003c\/h2\u003e\n\u003cp\u003eThe\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eWoodward 9905-971\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eserves as a high-speed intelligence node within the LON LINKNet distributed I\/O network, specifically engineered for mission-critical turbine and engine control environments. This module excels in monitoring the operational states of large-scale rotating machinery, where millisecond-level precision in signal acquisition is mandatory for safety and sequencing. By offering\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e24 discrete input channels\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003ewith an ultra-fast\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e5 ms update time\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eand\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1 ms resolution time-stamping\u003c\/strong\u003e, the 9905-971 captures transient events that standard I\/O modules might miss. This high-fidelity data acquisition allows plant operators to perform precise sequence-of-events (SOE) analysis, ensuring that trip conditions in reciprocating compressors or steam turbines are diagnosed with absolute chronological accuracy.\u003c\/p\u003e\n\u003ch2\u003eCore Technical Advantages\u003c\/h2\u003e\n\u003cp\u003eThe hardware architecture of the\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e9905-971\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eprioritizes fault tolerance and system integrity through advanced latent fault detection. Unlike conventional input modules, this unit features integrated readback circuitry that continuously monitors the state of relay contacts without disrupting active control operations.\u003c\/p\u003e\n\u003cp\u003eThe module utilizes a\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e24 Vdc contact wetting voltage\u003c\/strong\u003e, which can be sourced internally or from an external power supply to maintain signal clarity over long cable runs. Each discrete input is fully isolated, necessitating a common reference point that prevents ground loops and electrical interference from contaminating the control logic. Furthermore, the redundant relay output design ensures that contacts open and close in pairs. This mechanical redundancy guarantees that a single relay failure won't cause an accidental change of state, providing the \"fail-safe\" reliability required for high-availability industrial processes.\u003c\/p\u003e\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr class=\"firstRow\"\u003e\n\u003ctd\u003e\u003cstrong\u003eAttribute\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003eSpecification Detail\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eManufacturer\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eWoodward\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003ePart Number\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e9905-971\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eNumber of Channels\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e24 Discrete Inputs\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eInput Voltage\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e24 Vdc (Nominal)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eUpdate Time\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e5 ms\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eTime Stamping\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1 ms resolution\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eCommunication\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eLON LINKNet Protocol\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eIsolation\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eFully Isolated Inputs\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eOperating Temperature\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e-40°C to +70°C\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eDimensions\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e195 mm x 125 mm x 45 mm\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eWeight\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e0.9 kg (1.98 lbs)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch2\u003eInstallation \u0026amp; Engineering Guide\u003c\/h2\u003e\n\u003cp\u003eAchieving the rated 1 ms time-stamping accuracy with the\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eWoodward 9905-971\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003erequires careful attention to wiring topology. Engineers must establish a solid common reference point between the isolated inputs and the contact power source to ensure reliable signal transitions. We recommend using shielded twisted-pair cabling for all 24 channels to mitigate the effects of electromagnetic interference (EMI) generated by nearby high-voltage machinery.\u003c\/p\u003e\n\u003cp\u003eDuring installation into the LINKNet network, ensure the LON communication wires are properly terminated to prevent signal reflections that could lead to data dropouts. For fault-tolerant setups, verify that the latent fault detection software parameters are correctly configured in the main controller to utilize the module’s readback reports. When mounting, maintain adequate spacing for airflow to ensure the module stays within its -40°C to +70°C operating window, particularly in high-density control cabinets.\u003c\/p\u003e\n\u003ch2\u003eEngineering Advantages\u003c\/h2\u003e\n\u003cp\u003eThe\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e9905-971\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eoffers superior durability for demanding industrial sectors like offshore oil and gas and power generation. Its ability to detect relay failures before they impact the process—known as latent fault detection—provides a layer of predictive maintenance that standard discrete modules lack. This unit integrates seamlessly with Woodward's Turbo System Integrity (TSI) strategies, providing the ruggedized I\/O interface needed for reliable overspeed protection and emergency shutdown (ESD) sequences. Its rapid response and industrial-grade isolation make it a \"plug-and-play\" upgrade for aging control systems requiring enhanced diagnostic capabilities.\u003c\/p\u003e\n\u003ch2\u003eDelivery \u0026amp; Logistics\u003c\/h2\u003e\n\u003cp\u003eWe maintain a consistent inventory of the\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e9905-971\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eto support your urgent replacement and expansion projects.\u003c\/p\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eDelivery Time:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e3-5 business days upon payment completion.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eShipping Partners:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eFast global transit via DHL, FEDEX, or UPS.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eQuality Status:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eBrand New, Factory Sealed in original Woodward export packaging.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eTechnical FAQs\u003c\/h2\u003e\n\u003cp\u003eQ1: What is the benefit of 1 ms time-stamping on this module?\u003c\/p\u003e\n\u003cp\u003eA1: It allows for highly accurate Sequence of Events (SOE) logging. If a turbine trips, you can determine exactly which sensor triggered first, even if multiple events happen within the same 5ms update cycle.\u003c\/p\u003e\n\u003cp\u003eQ2: Can I use an external 24Vdc power source for contact wetting?\u003c\/p\u003e\n\u003cp\u003eA2: Yes, the\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e9905-971\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003esupports both internal and external 24 Vdc power sources for contact wetting, provided a common reference point is established.\u003c\/p\u003e\n\u003cp\u003eQ3: What happens if the readback circuitry detects a relay error?\u003c\/p\u003e\n\u003cp\u003eA3: The circuitry reports the error to the main controller and halts further testing of that specific relay to prevent accidental state changes, while allowing the rest of the control operation to continue unaffected.\u003c\/p\u003e\n\u003cp\u003eQ4: Is the module suitable for high-vibration environments?\u003c\/p\u003e\n\u003cp\u003eA4: Absolutely. Woodward designs the LINKNet series for installation on or near heavy industrial machinery, utilizing ruggedized connectors and solid-state components to resist mechanical stress.\u003c\/p\u003e","brand":"Woodward","offers":[{"title":"Default Title","offer_id":45927959527597,"sku":"9905-971","price":3499.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0733\/1613\/9181\/files\/9905-971_1.jpg?v=1776736719","url":"https:\/\/www.maxwellplc.com\/products\/woodward-9905-971-linknet-discrete-input-module-24-channel-24vdc-control","provider":"Maxwell PLC Ltd","version":"1.0","type":"link"}