Allen-Bradley 1746-NR4 SLC 500 RTD Input Module

The Allen-Bradley 1746-NR4 is a four-channel RTD/Resistance Input Module for the SLC 500 family, designed to connect four RTD sensors (such as Pt100) or resistance inputs directly to the backplane. Each channel uses sigma-delta A/D conversion with programmable low-pass filtering and notch options, and the module supports 2-wire and 3-wire RTD configurations for precise temperature measurements. The module draws power from the backplane (50 mA at 5 V and 50 mA at 24 V; up to 1.5 W total) with no external supply, and all four inputs are backplane isolated; it delivers high input performance with common-mode rejection >150 dB and normal-mode rejection >100 dB, a max common-mode voltage of ±1 V, and overload tolerance of ±5 V / ±5 mA. Auto-calibration occurs whenever a channel is enabled or its input type or filter settings change, and the NR4 is designed for installation in any I/O slot except slot 0 in the chassis.