Allen-Bradley 1746-NI4 4-Channel Input Module

The Allen-Bradley 1746-NI4 is a four-channel analog input module for the SLC 500 family, engineered to convert four analog signals into the PLC for real-time processing in legacy automation environments. It provides four differential input channels, with each channel configurable for either voltage or current input, and the channels are not individually isolated, sharing a common reference on the backplane. The module is designed to plug into a 1746 backplane and communicates with the CPU over the SLC‑500 I/O bus, with backplane power drawn at a 5V maximum. This makes the 1746-NI4 a practical choice for reading multiple analog sensor outputs in older installations or as part of a migration path within SLC 500-based control systems, where compact four-channel analog input coverage is needed in a single module.