Allen-Bradley 1771-QB PLC-5 Linear Positioning Module

Allen-Bradley 1771-QB PLC-5 Linear Positioning Module is a single-slot, closed-loop hydraulic positioning module for PLC-5 systems that uses a magnetostrictive linear displacement transducer to deliver precise position control. It occupies one slot in a 1771 Universal I/O rack and integrates with the PLC-5 control backbone for real-time feedback and motion commands. The module provides a 2 ms per-axis update period, with a backplane current load of 1.6 A max (typical about 1.1 A) to support servo drive and sensor circuitry. Digital inputs are auxiliary and require 8 mA per input at 12 V DC or 16 mA per input at 24 V DC, with logic 0 defined as 0–4 V and logic 1 as 10–30 V DC. On the outputs side, it provides a digital source to drive the servo valve and an analog output for the valve at 10 V DC with current capability options of 20 mA, 50 mA, or 100 mA, enabling precise valve actuation. This module is designed specifically for closed-loop linear positioning in hydraulic systems, making it suitable for applications where accurate, repeatable linear motion is required and where magnetostrictive transducer feedback is used. The 1771-QB is part of the PLC-5 1771 I/O family, so it can be configured alongside other 1771 modules in a compatible rack, enabling streamlined integration with existing PLC-5 controllers and I/O networks.