Allen-Bradley 1771-OAD AC Output Module

The Allen-Bradley 1771-OAD AC Output Module is a 16-channel digital output card for PLC-5/1771-series backplanes, designed to switch AC loads within a 12–120 V AC range. Each of its 16 discrete outputs is intended to drive AC devices such as relays, contactors, or other 120 V AC actuators directly from the PLC-5 controller, enabling centralized control of field devices from a single I/O module. The module is rack-mountable for straightforward integration into a standard PLC-5 chassis and communicates via the 1771 I/O backplane architecture. Typical installation guidance notes that the 1771-OAD can be used to drive an AC/DC (120 V) Input Module when paired with compatible hardware, reducing the need for intermediate interface components. The 12–120 V AC specification and 16-output configuration define the core capability of the 1771-OAD within the PLC-5 ecosystem, helping engineers plan panels for machine control, packaging lines, and process equipment that require direct AC switching from the PLC.