Allen-Bradley 1756-IF8I Isolated Analog Input Module

The Allen-Bradley 1756-IF8I Isolated Analog Input Module is an eight-channel input card for Rockwell Automation's ControlLogix systems. Each of its inputs is galvanically isolated from the backplane and from other channels, delivering a continuous isolation rating of 250 V for enhanced noise immunity and safety in rugged environments. The 36-pin module accepts either voltage or current signals on its eight isolated channels, with input ranges including -10 to 10 V, 0 to 10 V, 0 to 5 V, and 0 to 21 mA, and it provides 24-bit resolution per channel for precise digital representation. The IF8I can operate in both non-sourcing and sourcing current modes; in sourcing mode the channel can provide loop power to a connected sensor, while in non-sourcing mode the current input is passive. Total backplane power requirements are about 4.6 W in non-sourcing voltage mode and up to about 10.6 W when sourcing, reflecting the added burden of loop-powered operation. This module plugs into a ControlLogix backplane and communicates with the controller over the standard 1756 I/O backplane. Typical applications include monitoring analog sensors and transducers that output voltage in the -10 to 10 V range or current signals up to 21 mA, enabling isolated, precise data acquisition for process control, safety interlocks, and diagnostics.