Allen-Bradley 1756-IA16I Isolated 16-Point Input Module

The Allen-Bradley 1756-IA16I is a ControlLogix 16-point isolated input module that provides sixteen independently isolated AC input points on a single 1756 I/O card. It is designed for 79–132 V AC operation (nominally 120 V, 50/60 Hz) and uses a 36-pin backplane terminal block (RTB) interface to connect field signals to the ControlLogix backplane, delivering channel-to-channel isolation for improved noise immunity. Key electrical characteristics include a continuous isolation rating around 125 V, input delay times of roughly 8–10 ms (depending on voltage and user-selected filter settings), and per-channel on-state current typically between 5 and 15 mA with an off-state voltage limit of 20 V and off-state current up to 2.5 mA. The module integrates into the ControlLogix family for monitoring sixteen AC digital inputs from field devices such as sensors, switches, and relays, enabling discrete input processing with robust isolation across channels.