Allen-Bradley 1746-NIO4I | SLC 500 Analog Combination Module

Overview

The 1746-NIO4I is an Allen-Bradley SLC 500 analog combination module that integrates two voltage or current inputs and two current outputs within a single-slot design. It delivers high accuracy, fast response, and strong electrical isolation, making it suitable for process monitoring and precise control tasks.

Input Specifications

The module provides two differential input channels supporting ranges of -20 to +20 mA or -10 to +10 VDC. Each input channel achieves 16-bit resolution using a Sigma-Delta ADC converter. It ensures ±0.642% accuracy across 0 to 60°C, with normal mode rejection of 55 dB and common mode rejection of 105 dB at 60 Hz.

Output Specifications

The 1746-NIO4I offers two current output channels, each operating within 0–20 mA and supporting a 5% over-range capacity. The outputs deliver a resolution of 2.56348 µA per LSB and maintain ±0.541% accuracy with minimal drift. Each channel handles loads between 0 and 500 Ohms while maintaining stable operation.

Electrical Characteristics

This module consumes 55 mA from the 5V backplane and 145 mA from the 24V backplane. It features a 500V isolation barrier between field wiring and backplane circuitry, ensuring protection against electrical transients. Step response is 60 ms for inputs and only 2.5 ms for outputs, while the total update time for all channels is 512 µs.

Reliability and Environmental Ratings

The 1746-NIO4I operates reliably within temperatures of 0°C to 60°C and humidity levels of 5–95% non-condensing. Overvoltage protection supports up to 220 VAC RMS or 220 VDC continuously. The module maintains stable accuracy through gain and offset compensation, enabling dependable operation in demanding industrial environments.

Application Benefits

Engineers choose the 1746-NIO4I for applications requiring compact analog control in the SLC 500 system. Its combination of input and output channels, high-resolution conversion, and robust isolation make it ideal for monitoring temperature, pressure, level, and other analog signals with precision.