{"product_id":"allen-bradley-plc-5-1771-ds-latching-input-module","title":"Allen-Bradley 1771-DS PLC-5 Latching Input Module","description":"\u003cp\u003eThe Allen-Bradley 1771-DS is a specialized 8-input Latching Input Module designed for the PLC-5 system. It is engineered to detect and latch high-speed pulses that occur too rapidly for a standard PLC-5 scan rate to capture. When a pulse is detected at an input terminal, the module sets a corresponding bit in the input image table during the next I\/O scan.\u003c\/p\u003e\u003ch3\u003eFeatures\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e8-input latching capability for high-speed signal capture.\u003c\/li\u003e\n\u003cli\u003eSelectable pulse capture times: 0.1, 0.5, 1.0, 2.5, or 5.0 ms.\u003c\/li\u003e\n\u003cli\u003eOpto-electrical isolation of 1500V for signal integrity.\u003c\/li\u003e\n\u003cli\u003eSupports both master reset (all inputs) and individual input reset modes.\u003c\/li\u003e\n\u003cli\u003eCompatible with sensors featuring isolated pulse or gate outputs.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eApplications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eHigh-speed signal capture for processes exceeding standard PLC-5 scan rates.\u003c\/li\u003e\n\u003cli\u003eMaterial handling systems requiring precise position or product presence detection.\u003c\/li\u003e\n\u003cli\u003ePackaging equipment and pick-and-place machinery.\u003c\/li\u003e\n\u003cli\u003eCustom machine tool manufacturing and textile assembly lines.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003e1771-DS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInputs\u003c\/td\u003e\n\u003ctd\u003e8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Voltage (Logic 1)\u003c\/td\u003e\n\u003ctd\u003e10 to 27V DC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Voltage (Logic 0)\u003c\/td\u003e\n\u003ctd\u003e0 to 5V DC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNominal Input Current\u003c\/td\u003e\n\u003ctd\u003e20mA @ 27V DC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax Off-State Current\u003c\/td\u003e\n\u003ctd\u003e1mA @ 4V DC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBackplane Current\u003c\/td\u003e\n\u003ctd\u003e375mA typical\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIsolation\u003c\/td\u003e\n\u003ctd\u003e1500V Opto-electrical\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temperature\u003c\/td\u003e\n\u003ctd\u003e0 to 60 degC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch3\u003eInstallation Guidelines\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSlot Placement:\u003c\/strong\u003e The module can be installed in any I\/O slot of a 1771 chassis, excluding the far-left slot reserved for the processor or adapter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eKeying:\u003c\/strong\u003e To prevent incorrect module insertion, install keying bands on the backplane connector between pins 2 and 4, and between pins 18 and 20.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWiring:\u003c\/strong\u003e Connect field wiring to the appropriate field wiring arm (e.g., 1771-WH) before seating the module into the chassis.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHandling:\u003c\/strong\u003e Always power down the I\/O chassis before inserting or removing the module to prevent electrical damage or unexpected system behavior.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFAQs\u003c\/h3\u003e\u003ch3\u003eWhat is the 1771-DS Module?\u003c\/h3\u003e\u003cp\u003eThe 1771-DS is a Latching Input Module designed by Allen-Bradley for the PLC-5 system. It is an 8-input, rack-mountable module that operates within a 1771 I\/O chassis, commonly used to capture fast pulses.\u003c\/p\u003e\u003ch3\u003eWhat are the input voltage levels?\u003c\/h3\u003e\u003cp\u003eLogic 1 is 10-27V DC, and Logic 0 is 0-5V DC.\u003c\/p\u003e\u003ch3\u003eWhat sensors are compatible?\u003c\/h3\u003e\u003cp\u003eIt is designed for optical sensors with isolated pulse or gate outputs. The off-state leakage current of the sensors must not exceed 1mA @ 4V DC.\u003c\/p\u003e\u003ch3\u003eWhat is the modern replacement?\u003c\/h3\u003e\u003cp\u003eWhen upgrading from PLC-5 to ControlLogix (1756), users often replace it with high-speed modules like the 1756-IB16IF (Fast DC Input) or the 1756-IB16ISOE (Sequence of Events) to maintain fast response times.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":50956745539836,"sku":"1771-DS","price":99.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0787\/9983\/1292\/files\/wm_1_19cbc85e-4094-4e47-8d4b-b248806c97b0.jpg?v=1786321840","url":"https:\/\/www.electronicplc.com\/products\/allen-bradley-plc-5-1771-ds-latching-input-module","provider":"Electronic PLC","version":"1.0","type":"link"}