Allen-Bradley 1771-OA Output Module

The Allen-Bradley 1771-OA Output Module is an 8-point AC digital output card for the PLC-5 1771 I/O system, delivering eight 120 VAC outputs that switch line-voltage loads from your ladder logic. This single-slot module mounts in a 1771 I/O chassis and is designed for direct control of AC devices such as motor starters, solenoids, and other line-voltage actuators; its outputs use AC switching topology suitable for intermittent or continuous operation in factory automation. Manufacturer data notes that an output on the 1771-OA can drive a motor starter up to Allen-Bradley size 4, making it a compact option for modest motor control without external relays. In practice, the 1771-OA is commonly deployed to expand PLC-5 I/O with eight controllable AC channels in a single slot, preserving cabinet space while enabling straightforward integration with existing PLC-5 programs.