Allen-Bradley 1747-NI4 SLC 500 Analog Input Module

Allen-Bradley 1747-NI4 is a four-channel analog input module for SLC 500 systems on the 1747/RIO remote I/O bus. It reads analog signals from field sensors and transducers, converting them to digital values that the PLC uses for monitoring and control. Each channel can be configured to accept different electrical signals, allowing a mix of voltage and current sensors on a single module. The NI4 populates the SLC data image with one word per channel, which simplifies ladder logic addressing and data collection from distributed instrumentation. It requires a compatible SLC 500 chassis and backplane and communicates with the CPU over the 1747 RIO network. Typical applications include process monitoring of temperature, pressure, flow, and level sensors, as well as remote data acquisition and basic instrumentation in manufacturing lines. As part of a modular I/O strategy, the NI4 can be combined with other 1747 I/O modules to expand analog input capacity without changing the CPU, making it a common choice for legacy AB deployments that still rely on SLC 500 hardware.