{"product_id":"woodward-9905-971-industrial-automation-module-heavy-duty","title":"Woodward 9905-971 Industrial Automation Module - Heavy-Duty","description":"\u003ch2\u003eProduct Overview\u003c\/h2\u003e\u003cp\u003eWhen fault tolerance is critical in your control system, the \u003cstrong\u003eWoodward 9905-971\u003c\/strong\u003e Discrete Input Module provides robust monitoring and detection capabilities. Designed for industrial automation, this module supports 24 discrete input channels and integrates latent fault detection to prevent undetected relay failures. Each input operates at 24 Vdc, and the module’s series-parallel relay configuration ensures that a single relay failure does not compromise output integrity.\u003c\/p\u003e\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\u003cp\u003eThe \u003cstrong\u003eWoodward 9905-971\u003c\/strong\u003e delivers reliable performance with the following key parameters:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eNumber of channels:\u003c\/strong\u003e 24\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUpdate time:\u003c\/strong\u003e 5 ms\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTime stamping resolution:\u003c\/strong\u003e 1 ms\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInput voltage:\u003c\/strong\u003e 24 Vdc\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCountry of manufacture:\u003c\/strong\u003e United States\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eEach channel detects input states with 1 ms timestamp accuracy, making the 9905-971 suitable for high-speed event recording.\u003c\/p\u003e\u003ch2\u003eIndustry Applications\u003c\/h2\u003e\u003cp\u003eThe \u003cstrong\u003eWoodward 9905-971\u003c\/strong\u003e is ideal for turbine control, gas compression, and power generation systems where fault tolerance is paramount. In a gas turbine supervisory system, latent fault detection ensures that a single relay failure does not cause an unexpected shutdown. For emergency shut‑down circuits, the module’s ability to detect relay failures without affecting output state improves overall system reliability.\u003c\/p\u003e\u003ch2\u003eInstallation \u0026amp; Setup Guidance\u003c\/h2\u003e\u003cp\u003eInstall the \u003cstrong\u003eWoodward 9905-971\u003c\/strong\u003e by inserting it into the control chassis card guides and securing it with the top and bottom screws. Two handles allow easy disengagement from the motherboard. When using internal 24 Vdc contact wetting, install jumpers between terminals 33, 34, and 35. If an external 18–32 Vdc or 100–150 Vdc source is used, connect its common to terminals 34 and 35. Ensure all discrete inputs share a common reference point with the contact power source.\u003c\/p\u003e\u003ch2\u003eMaintenance \u0026amp; Reliability\u003c\/h2\u003e\u003cp\u003eThe \u003cstrong\u003eWoodward 9905-971\u003c\/strong\u003e uses latent fault detection to periodically test relay contacts without disrupting operation. This routine self‑testing—opening and closing relays in pairs—detects stuck or failed contacts early. For maximum reliability, inspect the module during scheduled maintenance and verify that readback circuitry reports no errors. The 9905-971’s series‑parallel relay design means that even if two relays fail, the output remains in the correct state.\u003c\/p\u003e\u003ch2\u003eSelection Guide \u0026amp; Purchasing Advice\u003c\/h2\u003e\u003cp\u003eBefore purchasing a \u003cstrong\u003eWoodward 9905-971\u003c\/strong\u003e, verify that your system’s chassis supports 24‑channel discrete input modules and that the contact wetting voltage matches your supply (24 Vdc internal or external 18–32 Vdc \/ 100–150 Vdc). Confirm the required number of modules per controller (the control accepts four modules, each handling six contact inputs). For reliable supply and rapid support, choose a trusted distributor like \u003cstrong\u003ePLC Source PRO\u003c\/strong\u003e (available at ubest101.myshopify.com). The 9905-971 is in stock with a typical repair turnaround of 3–7 days.\u003c\/p\u003e","brand":"Woodward","offers":[{"title":"Default","offer_id":44416649560163,"sku":"9905-971","price":297.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0678\/8635\/0435\/files\/9905-204_912f447c-9a98-4c71-b418-f4806c7c45bb.jpg?v=1785250411","url":"https:\/\/www.plcsourcepro.com\/products\/woodward-9905-971-industrial-automation-module-heavy-duty","provider":"PLC Source PRO","version":"1.0","type":"link"}