{"product_id":"1771-pd-allen-bradley-pid-control-module","title":"1771-PD | Allen-Bradley  PID Control Module","description":"\u003cp\u003eThe \u003cstrong\u003e1771-PD\u003c\/strong\u003e is a specialized Allen-Bradley PLC 1771 I\/O chassis-compatible control module designed for closed-loop process control within PLC-5 and 1771-based system architectures. Featuring Series A hardware design, this intelligent module provides standalone execution of up to two independent PID (Proportional, Integral, Derivative) control loops directly on the I\/O backplane, offloading compute-intensive closed-loop algorithms from the primary processor. It requires 1.2 A at 5 VDC backplane power and operates as a Class 2 control device with a total maximum output power rating of 4.2 VA.\u003c\/p\u003e\n\u003ch3\u003eFunctionality and Control Architecture\u003c\/h3\u003e\n\u003cp\u003eThe module functions by reading process variables, computing error values, and applying PID algorithm corrections across two separate loops. By executing loop update calculations locally on the module, it minimizes scan time overhead on the main PLC processor while maintaining deterministic loop timing. Communication with the host processor occurs via standard 1771 block transfer reads and writes.\u003c\/p\u003e\n\u003ch3\u003ePower Requirements and Physical Specifications\u003c\/h3\u003e\n\u003cp\u003eThe module interfaces directly with standard 1771 I\/O chassis backplanes, drawing logic power directly from the chassis power supply.\u003c\/p\u003e\n\u003cfigure class=\"table\"\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eParameter\u003c\/strong\u003e\u003c\/th\u003e\n\u003cth\u003e\u003cstrong\u003eSpecification\u003c\/strong\u003e\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-PD\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\u003eProduct Type\u003c\/td\u003e\n\u003ctd\u003ePID Control Modules\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSeries\u003c\/td\u003e\n\u003ctd\u003eSeries A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eControl Loops\u003c\/td\u003e\n\u003ctd\u003e2 Independent Loops\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBackplane Current\u003c\/td\u003e\n\u003ctd\u003e1.2 A @ 5 VDC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Output Rating\u003c\/td\u003e\n\u003ctd\u003e4.2 VA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eClass Rating\u003c\/td\u003e\n\u003ctd\u003eClass 2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e4.40 lbs (2.00 kg)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLifecycle Status\u003c\/td\u003e\n\u003ctd\u003eDiscontinued by Manufacturer (June 5, 2009)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003cp\u003eFrequently Asked Questions\u003c\/p\u003e\n\u003cp\u003eQ: How does the 1771-PD module transfer control loop data to the main PLC processor? A: The module transfers configuration data, setpoints, process variables, and tuning parameters using 1771 Block Transfer Instructions (BTR\/BTW) over the chassis backplane.\u003c\/p\u003e\n\u003cp\u003eQ: Can the 1771-PD module operate independently if host processor communication is interrupted? A: The module executes its dual PID control loops locally using its internal firmware, maintaining loop operation based on its last configuration depending on user-programmed fallback states.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":67099824980083,"sku":"1771-PD","price":88.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0644\/4348\/2227\/files\/1771-SIM4_Cocoai_0d8615e0-4115-4299-acfe-575384e19704.jpg?v=1793690329","url":"https:\/\/www.dcssupplier.com\/products\/1771-pd-allen-bradley-pid-control-module","provider":"DcsSupplier Limited","version":"1.0","type":"link"}