Allen-Bradley 1746-IH16 16-Point Isolated Input Module

The Allen-Bradley 1746-IH16 is a 16-point discrete input module for the SLC 500 system, delivering isolated current-sinking 125 VDC inputs that map to a single 16‑bit input word. It uses a removable terminal block, installs in any free 1746 I/O chassis slot, and provides electrical isolation between the input circuits and the controller to protect the backplane from field wiring transients. Each input draws about 2.15 mA at 125 V DC (2.25 mA at 132 V DC), and the module is designed for 125 VDC sensing with inputs that are isolated from the PLC logic; it is C-UL and CSA-certified. This configuration is commonly used to read sensors and switches in industrial automation where 125 VDC signals are present, providing 16 independent points in a compact single-input-word package.