Allen-Bradley 1756-IA16I AC Isolation Input Module

Allen-Bradley 1756-IA16I is a ControlLogix digital input module offering sixteen independently isolated AC input points, designed to bring 120V AC control signals into the backplane with robust channel-to-channel and channel-to-backplane isolation. Each of the 16 inputs accepts a nominal 120V AC signal with an operating range of about 79–132V AC at 50/60 Hz, making it suitable for standard industrial switches, relays, and sensors in mid‑scale automation. The module provides continuous isolation rated at 125V between inputs and the backplane (and input-to-input), helping suppress noise and fault propagation across channels. It draws power from the backplane (about 0.71 W total) and dissipates up to around 4.9 W at 60 °C, with a thermal dissipation of roughly 16.7 BTU/hr. For signal integrity, the 1756-IA16I includes a hardware input delay with user-selectable filtering to accommodate contact bounce and comms timing, typically adding a few milliseconds to the input transition. Wiring is accomplished via removable terminal blocks, and the card is compatible with standard ControlLogix racks in 16-point configurations when paired with appropriate backplane voltage and a compatible chassis. Applications include interfacing 120V AC pushbuttons, limit and limit-switch contacts, and other discrete sensors in process rooms, conveyors, and machine controls where galvanic isolation improves reliability and safety.