1746-NO8I | Allen-Bradley | SLC 500 Analog Current Output Module

Product Overview

The Allen-Bradley 1746-NO8I functions as a high-density analog output interface for the SLC 500 controller platform. This module provides eight high-precision current output channels, allowing the PLC to drive multiple field devices such as actuators, valves, and motor speed controllers simultaneously. We supply this unit in 100% Brand New, original factory condition, ensuring your legacy SLC systems maintain maximum uptime with hardware that meets the latest manufacturer revisions.

Technical Specifications

Engineering Advantages

• High-Density Control: The 1746-NO8I consolidates eight analog channels into a single SLC slot. This reduces the number of required chassis slots compared to lower-density modules, freeing up space for additional I/O or specialized communication cards.

• Ultra-Fast Signal Response: The 1 ms step response ensures nearly instantaneous control over field actuators. This speed proves critical in closed-loop PID applications where system stability depends on rapid corrections to process variables.

• Flexible Data Formatting: The module supports multiple data formats including Scaled Engineering Units, PID scaling, and user-defined scales. This flexibility eliminates complex math blocks within the ladder logic, simplifying code development and troubleshooting.

• Broad Output Range Support: It handles diverse current ranges up to 21.5 mA. This extended range allows for "over-range" signaling, which engineers frequently use to detect valve sticking or saturation points in process instrumentation.

• Robust Terminal Termination: The module accepts two 14 to 24 AWG wires per terminal. This allows for easy "daisy-chaining" of common signals directly at the module face, reducing the need for external distribution terminal blocks inside the cabinet.

FAQs

• Does this unit replace the older 1746-NO4I module?

  Yes. While the 1746-NO8I provides double the density, it uses the same SLC 500 backplane interface. You must update your I/O configuration in RSLogix 500 to account for the increased channel count and different data word requirements.

• What is the significance of "Class 1" and "Class 3" update times?

  The update time depends on the processor and chassis configuration. Class 1 operation provides a faster 5 ms update rate, ideal for high-speed motion or pressure control, while Class 3 provides a 10 ms rate suitable for standard temperature or level control.

• Does the module require an external power supply?

  The 1746-NO8I draws its operating power (120 mA @ 5V and 250 mA @ 24V) directly from the SLC 500 chassis backplane. Ensure your power supply (e.g., 1746-P1, P2, or P4) has sufficient headroom to support these requirements.

• Is this product a refurbished or used unit?

  Absolutely not. We guarantee this 1746-NO8I is 100% Brand New. It ships in the original Allen-Bradley factory packaging with intact security seals and full technical documentation.