Allen-Bradley 1746-IO8 SLC 500 Digital I/O Module

June 23, 2026 • 2 min read • wayne • Industry News

The 1746-IO8 from Allen-Bradley delivers a robust combination of digital inputs and relay outputs. This module integrates directly into the SLC 500 system. Engineers value its flexible I/O configuration for diverse applications. The unit fits any chassis slot except slot zero. It offers four 120V AC inputs for monitoring signals. The module also provides four relay contact outputs for control. This design simplifies wiring and reduces panel space requirements. You can trust this module for non-hazardous and specific hazardous environments.

Theme D: Expert Technical Evaluation & Performance Review

The 1746-IO8 operates reliably within a voltage range of 85 to 132 Volts AC. This specification matches standard industrial power supplies. The module features a signal delay between 35 and 45 milliseconds. This delay applies to both input and output ON and OFF states. Such timing ensures predictable system response during operations. The relay outputs use Normally Open (N.O.) contacts for safety. Each output point handles 1.5 amps continuous at 120V AC. Each point also manages 1.2 amps continuous at 24V DC.

This module demonstrates excellent thermal management capabilities. The total aggregate heat dissipation measures just 3 Watts. Each input point dissipates 0.27 Watts of power. Each output point dissipates only 0.133 Watts. The backplane draws a minimal current of 0.03A at 5V DC. It also draws 0.025A at 24V DC. These low values reduce strain on the system power supply.

The environmental tolerances of this unit are equally impressive. The factory specifies an operating temperature range from 0 to 60 °C. The non-operational range extends from -40 to 85 °C. This allows safe storage in extreme conditions. The module withstands operational shock up to 30G. It also resists operational vibration of 2.5G at 57-200Hz. These ratings guarantee performance in demanding industrial settings.

The module holds CE, CSA, and C-UL certifications for global use. It provides NEMA standard ICS 2-230 rated noise immunity. This immunity protects signal integrity in electrically noisy plants. The 1746-IO8 is a proven workhorse for mixed I/O needs.