{"product_id":"allen-bradley-1771-a4b-plc-universal-i-o-chassis-16-slot-rack-assembly","title":"Allen-Bradley 1771-A4B PLC Universal I\/O Chassis | 16-Slot Rack Assembly","description":"\u003ch3\u003e\u003cstrong\u003eOverview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1771-A4B\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e(Catalog Number:\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1771-A4B\u003c\/strong\u003e) serves as a high-capacity foundation for Allen-Bradley PLC-5 systems. This 16-slot universal I\/O chassis provides the mechanical framework and electrical backplane necessary for housing a diverse array of 1771-series modules. Engineered for back-panel mounting within a control enclosure, it ensures rigid support and high-current power distribution across the entire backplane bus, supporting both local and remote I\/O configurations.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eTechnical Specifications\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1771-A4B\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eis designed to handle heavy-duty industrial loads and provide maximum module density.\u003c\/p\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eSlot Capacity\u003c\/strong\u003e: 16 Total I\/O Slots\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eMaximum Backplane Current\u003c\/strong\u003e: 24.0 Amperes @ 5V DC\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eMounting Configuration\u003c\/strong\u003e: Back-panel (Sub-panel) mounting\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eEnclosure Architecture\u003c\/strong\u003e: Open-style chassis\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eOperational Vibration\u003c\/strong\u003e: 2 g @ 10 to 500 Hz\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eShock Resistance\u003c\/strong\u003e: 15 g (Operational); 30 g (Non-operational)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003ePhysical Weight\u003c\/strong\u003e: 7.7 kg (14.8 lbs)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eChassis Dimensions\u003c\/strong\u003e: Approximately 19.0 x 6.5 x 2.0 inches (Note: Standard 16-slot width is approximately 483 mm; verify enclosure clearance accordingly)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eAtmospheric Tolerance\u003c\/strong\u003e: 5% to 95% Relative Humidity (Non-condensing)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eEnvironmental Operating Limits\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis chassis is rated for continuous operation in standard industrial environments.\u003c\/p\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eAmbient Operating Temperature\u003c\/strong\u003e: 0°C to 60°C (32°F to 140°F)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eStorage\/Transport Temperature\u003c\/strong\u003e: -40°C to 85°C (-40°F to 185°F)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003ePower Integration and Sourcing\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1771-A4B\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003ebackplane can be energized through multiple sourcing methods depending on the system architecture:\u003c\/p\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eProcessor Sourced\u003c\/strong\u003e: Directly through the 1771 processor module.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eChassis-Resident Modules\u003c\/strong\u003e: Slot-mounted power supply modules (e.g., 1771-P4, P7).\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eRemote\/External Sources\u003c\/strong\u003e: Heavy-duty standalone power supplies connected via the chassis power terminal strip.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eLegacy System Comparison and FAQ\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eHow does the 1771-A4B differ from the 1771-A1B?\u003c\/strong\u003eWhile both belong to the Universal I\/O family, the\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1771-A4B\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eoffers the maximum capacity of 16 slots, whereas the 1771-A1B is limited to 4 slots. The A4B is the preferred choice for centralized high-density I\/O requirements.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan this chassis be used with EtherNet\/IP?\u003c\/strong\u003eThe chassis itself is a passive backplane. However, by installing a 1771-AENTR adapter, this legacy 16-slot rack can be integrated into modern EtherNet\/IP networks, allowing older I\/O modules to communicate with ControlLogix or CompactLogix controllers.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the correct mounting orientation?\u003c\/strong\u003eFor optimal thermal dissipation, the chassis should be mounted horizontally on a vertical back-panel. Ensure adequate spacing above and below the rack to allow for natural convection cooling of the installed modules.\u003c\/p\u003e","brand":"Allen Bradley","offers":[{"title":"Default Title","offer_id":52887517528248,"sku":"1771-A4B","price":99.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0935\/6132\/3704\/files\/1771-A4B1.jpg?v=1772094969","url":"https:\/\/www.globalpetroparts.com\/products\/allen-bradley-1771-a4b-plc-universal-i-o-chassis-16-slot-rack-assembly","provider":"Global Petro Parts Automation","version":"1.0","type":"link"}