Allen-Bradley 1746-NR4 4-Channel RTD Resistance Input Module

Allen-Bradley 1746-NR4 is a four-channel RTD/Resistance analog input module for the SLC 500 family. It plugs into a backplane and provides four isolated RTD/resistance input channels, enabling direct connection of resistance-based sensors to a Rockwell Automation controller. The module is designed for the SLC 500 ecosystem and integrates with the 1746 backplane to deliver channel-by-channel measurements that the CPU can read as digital values. A set of five LEDs—one for the module status and one for each channel—offers at-a-glance health and input status. This NR4 module reads resistance-type sensors and is commonly used for temperature monitoring and other RTD-resistance measurements in industrial automation, HVAC, and process control environments where four independent RTD signals must be read simultaneously. It supports backplane isolation and maps each channel to a PLC address within the SLC 500 I/O tree, enabling straightforward integration with existing Rockwell workflows.