Allen-Bradley 1746-NI8 8-Channel Analog Input Module

Allen-Bradley 1746-NI8 is an eight-channel analog input module for the SLC 500 system that provides differential, non-isolated inputs and allows per-channel configuration for either voltage or current measurement. It mounts in a 1746 backplane and uses a removable terminal block (1746RT25G) for wiring; Belden 8761 or equivalent cable is recommended, with up to two 14 AWG conductors per terminal. The module includes nine green indicators—one for each of the eight channels and a module-status LED—to convey channel and overall status. For wiring, the recommended loop impedance is 40 ohms max for voltage-mode inputs (with source impedance under 10 ohms) and 250 ohms max for current-mode inputs. Discontinued as of September 30, 2024, the NI8 remains a legacy option for maintaining or repairing older SLC 500 systems that require eight analog inputs in a single card, and it is typically used to monitor process signals such as temperature, pressure, or flow from analog sensors feeding into the PLC.