Allen-Bradley 1771-0D Isolated AC Output Module

The Allen-Bradley 1771-0D Isolated AC Output Module is a six‑output digital I/O module for PLC‑5 systems that switches 120 V AC loads from the 1771 backplane. Each of the six outputs is isolated from the controller, providing galvanic isolation between field wiring and the PLC backplane to help protect the processor from load transients. The module is designed for nominal 120 V AC operation with an operating range roughly 92–138 V AC, and it draws about 225 mA from the backplane. Typical applications include energizing AC relays, contactors, or other 120 V AC devices in industrial automation panels where isolated, discrete control signals are required from the PLC‑5. Compatible with standard 1771 I/O chassis used in PLC‑5 installations, the 1771-0D (also cataloged as 1771-OD) provides a compact, isolated means to extend the controller’s reach to AC loads while maintaining separation between field wiring and the control logic.