Description

The Allen-Bradley 1746-NT8 is a specialized analog input module designed for the SLC 500 programmable logic controller system. This module provides 8 input channels specifically configured for thermocouple and millivolt (mV) signal processing. It is engineered to interface directly with various temperature sensors, allowing for precise monitoring and control of industrial processes requiring thermal data acquisition.

Features

• 8 isolated input channels for thermocouple or millivolt signals.
• Compatible with standard SLC 500 chassis and backplane configurations.
• Supports multiple thermocouple types (J, K, T, E, R, S, B, N) and millivolt ranges.
• Integrated cold junction compensation for accurate temperature measurement.
• Digital filtering to minimize noise interference in industrial environments.

Applications

This module is widely used in industrial automation applications where temperature monitoring is critical, such as furnace control, heat treatment processes, chemical reactors, and environmental monitoring systems within the SLC 500 platform.

Technical Specifications

Installation Guidelines

• Ensure the SLC 500 chassis power is disconnected before installing or removing the module.
• Use shielded twisted-pair cabling for all thermocouple and millivolt inputs to reduce electromagnetic interference (EMI).
• Ensure proper grounding of the module chassis to the system ground bus.
• Avoid routing signal wires alongside high-voltage AC power lines or motor control cables.
• Verify that the thermocouple polarity is correct at the terminal block to prevent measurement errors.
• Handle the module using ESD-safe practices to prevent damage to internal circuitry.

FAQ

Q: Is the 1746-NT8 a digital input module?
A: No, despite some legacy references, the 1746-NT8 is an analog input module specifically designed for thermocouple and millivolt signals, not standard 24VDC digital inputs.

Q: Does this module require external power?
A: The module draws its primary operating power from the SLC 500 backplane. Ensure your power supply is sized correctly to handle the total current draw of all modules in the rack.