{"product_id":"1771-ih-industrial-automation-module-stable-by-allen-bradley","title":"1771-IH  Industrial Automation Module - Stable by Allen-Bradley","description":"\u003ch2\u003eProduct Overview\u003c\/h2\u003e\u003cp\u003eThe Allen-Bradley 1771-IH is a digital DC input module designed for the PLC 5 family and Bulletin 1771 I\/O system. This rack-mountable module provides eight input channels and uses a wiring arm for straightforward installation. It operates on a DC supply with a voltage range of 24 to 48 Volts DC, making it suitable for a variety of industrial control applications.\u003c\/p\u003e\u003cp\u003eWith its robust design and reliable performance, the 1771-IH is a trusted choice for monitoring discrete DC signals in manufacturing and process environments. Its status indicators provide immediate visual feedback on input states, simplifying diagnostics and maintenance.\u003c\/p\u003e\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\u003cp\u003eBelow are the key specifications for the Allen-Bradley 1771-IH module:\u003c\/p\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eManufacturer\u003c\/td\u003e\n\u003ctd\u003eRockwell Automation\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\u003ePart Number\u003c\/td\u003e\n\u003ctd\u003e1771-IH\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModule Type\u003c\/td\u003e\n\u003ctd\u003eDigital DC Input Module\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNumber of Inputs\u003c\/td\u003e\n\u003ctd\u003e8 Inputs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVoltage Category\u003c\/td\u003e\n\u003ctd\u003e10-60 Volts DC, Sink (Source Load)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDC Operating Voltage\u003c\/td\u003e\n\u003ctd\u003e24-50 Volts\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBackplane Current\u003c\/td\u003e\n\u003ctd\u003e74 Milliamperes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax DC Off-State Current\u003c\/td\u003e\n\u003ctd\u003e0.7 Milliamperes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTypical DC Signal Delay (On)\u003c\/td\u003e\n\u003ctd\u003e15 (±7) ms\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTypical DC Signal Delay (Off)\u003c\/td\u003e\n\u003ctd\u003e20 (±9) ms\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWiring Arm\u003c\/td\u003e\n\u003ctd\u003e1771-WA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel Status\u003c\/td\u003e\n\u003ctd\u003eEarlier Model\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTypical AC Signal Delay (Off)\u003c\/td\u003e\n\u003ctd\u003e24 (±10) ms\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting\u003c\/td\u003e\n\u003ctd\u003eRack Mountable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003cp\u003eAdditionally, the module has a maximum on-state voltage of 10V DC, a maximum off-state voltage of 4.5V DC, and a maximum off-state current of 1 mA. The input impedance ranges from 2.5–3K Ω in the on-state and 5–6K Ω in the off-state. Eight red status indicators are provided for each channel.\u003c\/p\u003e\u003cp\u003eSignal propagation delays are specified at 15 ms (±7 ms) for both low-to-high and high-to-low transitions. The backplane current is 74 mA at 5V DC (±5%), and the isolation voltage is 1500V AC RMS. Power dissipation ranges from 0.4 W to 8.1 W, with thermal dissipation from 1.3 BTU\/hr to 27.7 BTU\/hr. The operating temperature range is 0 to 60 °C (32 to 140 °F).\u003c\/p\u003e\u003ch2\u003eIndustry Applications\u003c\/h2\u003e\u003cp\u003eThe 1771-IH is ideal for applications requiring reliable DC input sensing, such as:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eMonitoring limit switches and proximity sensors in automated assembly lines.\u003c\/li\u003e\n\u003cli\u003eReading discrete status signals from motor control centers.\u003c\/li\u003e\n\u003cli\u003eInterfacing with push-button and selector switch inputs in control panels.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eIts wide voltage range and sink configuration make it compatible with many industrial DC power supplies. When upgrading legacy PLC 5 systems, the 1771-IH provides a drop-in solution that maintains system integrity while offering dependable performance.\u003c\/p\u003e\u003ch2\u003eInstallation \u0026amp; Setup\u003c\/h2\u003e\u003cp\u003eMount the 1771-IH in any available slot of a 1771 I\/O chassis. Ensure the backplane connector aligns properly and secure the module in place. Connect field wiring using the 1771-WA wiring arm (or 1771-WD if specified). Verify that the DC supply voltage is within the 24–48V range and that the input signals meet the sink configuration requirements. After installation, power up the system and check the status indicators to confirm proper operation.\u003c\/p\u003e\u003ch2\u003eMaintenance \u0026amp; Reliability\u003c\/h2\u003e\u003cp\u003eRoutine inspection includes checking for loose wiring, verifying that the module is seated correctly, and ensuring that the operating environment stays within the specified temperature range. Because the 1771-IH is an earlier model, regular monitoring of input signal integrity can help prevent unexpected downtime. Keeping spare modules on hand minimizes production interruptions.\u003c\/p\u003e\u003ch2\u003eCompatibility \u0026amp; Integration\u003c\/h2\u003e\u003cp\u003eThe 1771-IH is designed for use with Allen-Bradley PLC 5 processors and the Bulletin 1771 I\/O system. It is rack-mountable and uses the standard 1771 backplane interface. The module works with the 1771-WA wiring arm (or 1771-WD) for field wiring connections. No additional communication protocols are required; it operates as a standard I\/O module within the PLC 5 architecture.\u003c\/p\u003e\u003ch2\u003eSelection Guide \u0026amp; Purchasing Advice\u003c\/h2\u003e\u003cp\u003eBefore purchasing, verify that the 1771-IH meets your input voltage and sink\/source requirements. Confirm that your chassis has an available slot and that the wiring arm matches your field wiring configuration. PLC Source PRO offers genuine Allen-Bradley 1771-IH modules with reliable availability. Ensure you order the correct module for your system to avoid compatibility issues.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default","offer_id":44438799581283,"sku":"1771-IH","price":231.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0678\/8635\/0435\/files\/1771-A3B1_281_29_6b8601e3-37d0-4e83-9336-fb020d4d39b5.jpg?v=1785851794","url":"https:\/\/www.plcsourcepro.com\/he\/products\/1771-ih-industrial-automation-module-stable-by-allen-bradley","provider":"PLC Source PRO","version":"1.0","type":"link"}