{"product_id":"allen-bradley-1771-qrc-quadrature-reference-counter-module","title":"Allen-Bradley 1771-QRC Quadrature Reference Counter Module","description":"\u003ch2\u003eAllen-Bradley 1771-QRC Quadrature Reference Counter Module\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eAllen-Bradley 1771-QRC\u003c\/strong\u003e, also cataloged as the \u003cstrong\u003e1771-QRC\u003c\/strong\u003e Quadrature Counter Module, operates as a dedicated hardware component for high-speed encoder signal counting and position feedback processing within PLC-5 and 1771 I\/O system platforms. The module receives A, B, and Z pulse inputs for real-time position tracking, velocity measurement, and reference comparison operations.\u003c\/p\u003e\n\u003ch3\u003eHardware Specifications\u003c\/h3\u003e\n\u003cfigure class=\"table\"\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003e1771-QRC\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\u003eOrigin\u003c\/td\u003e\n\u003ctd\u003eUnited States\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e1.39 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e115 x 317 x 160 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temp\u003c\/td\u003e\n\u003ctd\u003e0 to 60 deg C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Consumption\u003c\/td\u003e\n\u003ctd\u003e1.0 A typical at 5 VDC backplane\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Type\u003c\/td\u003e\n\u003ctd\u003eQuadrature Counter Modules\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEncoder Inputs\u003c\/td\u003e\n\u003ctd\u003eQuadrature A, B, and Z channels\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Voltage\u003c\/td\u003e\n\u003ctd\u003e5 VDC TTL compatible\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Input Frequency\u003c\/td\u003e\n\u003ctd\u003eUp to 1 MHz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCounter Resolution\u003c\/td\u003e\n\u003ctd\u003e12-bit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReference Registers\u003c\/td\u003e\n\u003ctd\u003eProgrammable position comparison registers\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOutputs\u003c\/td\u003e\n\u003ctd\u003e2 normally open relay outputs; reference triggered outputs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRelay Output Rating\u003c\/td\u003e\n\u003ctd\u003e0.5 A at 5 VDC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWiring Arm\u003c\/td\u003e\n\u003ctd\u003e1771-WN\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting\u003c\/td\u003e\n\u003ctd\u003e1771 Universal I\/O chassis\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEnclosure Type\u003c\/td\u003e\n\u003ctd\u003eOpen style\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eEtherNet\/IP and PLC-5 Backplane Interface Characteristics\u003c\/h3\u003e\n\u003cp\u003eThe 1771-QRC operates as a PLC-5 I\/O subsystem module using the 1771 backplane interface for data exchange and control execution. The module processes incremental encoder signals through quadrature decoding logic and provides position and velocity data to the control system.\u003c\/p\u003e\n\u003cp\u003eThe module supports deterministic encoder signal processing with programmable reference registers for event triggering at defined count positions. The I\/O architecture allows position feedback integration with PLC-5 motion applications while maintaining I\/O density scaling within the 1771 chassis platform.\u003c\/p\u003e\n\u003cp\u003eEncoder signal integrity depends on correct cable routing, shielding, and grounding practices. The module requires compatible TTL-level encoder inputs and supports diagnostics for signal loss and phase detection errors.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003eQ: What type of encoder signals does the 1771-QRC accept?\u003cbr\u003eA: The module accepts quadrature A, B, and Z index signals from incremental encoders with 5 VDC TTL-compatible output levels.\u003c\/p\u003e\n\u003cp\u003eQ: What is the maximum encoder input frequency supported by the 1771-QRC?\u003cbr\u003eA: The module supports encoder input frequencies up to 1 MHz.\u003c\/p\u003e\n\u003cp\u003eQ: What backplane power requirement does the 1771-QRC have?\u003cbr\u003eA: The module requires approximately 1.0 A at 5 VDC from the 1771 chassis backplane.\u003c\/p\u003e\n\u003ch3\u003eField Installation Guidelines\u003c\/h3\u003e\n\u003cp\u003eInstall the 1771-QRC in a compatible 1771 Universal I\/O chassis and verify available backplane power capacity before operation. Use the specified 1771-WN wiring arm for field connections and confirm encoder wiring compatibility.\u003c\/p\u003e\n\u003cp\u003eRoute encoder signal cables separately from high-current motor and actuator wiring to reduce electrical noise. Use shielded cables and terminate shields according to the control cabinet grounding design.\u003c\/p\u003e\n\u003cp\u003eVerify encoder phase sequence, signal polarity, and index pulse configuration during commissioning. Confirm relay output wiring and external load requirements before enabling reference-triggered operations.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":43701271658586,"sku":"1771-QRC","price":123.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0612\/4601\/3530\/files\/1771-QRC2.jpg?v=1784701473","url":"https:\/\/www.plcmasters.com\/products\/allen-bradley-1771-qrc-quadrature-reference-counter-module","provider":"PLC Masters Ltd.","version":"1.0","type":"link"}