The Allen-Bradley 1746-NT8 is an 8-channel input module for the SLC 500 series PLCs. It converts analog signals from thermocouples or millivolt sensors into digital values for processing.

Technical Specifications

• Number of Channels: 8
• Input Type: Thermocouple/mV
• Input Range: ±50 mV or ±100 mV
• Resolution: 16-bit
• Accuracy: ±0.1% of full scale
• Nonlinearity: ±0.05% of full scale
• Input Impedance: Greater than 2 MΩ
• Update Time: 540 microseconds
• Power Requirements: 24 V DC or external 24 V DC power supply
• Power Consumption: Typical 1.2 W, maximum 1.5 W
• Operating Temperature: -10°C to 55°C
• Storage Temperature: -40°C to 70°C
• Protection: IP20

Features

• High Accuracy: Achieves precise analog voltage output with 16-bit resolution and ±0.1% full scale accuracy.
• Programmability: Supports channel scaling, limit alarming, data scaling, and filtering for diverse applications.
• Cold Junction Compensation: Uses external sensors or software compensation to correct thermocouple measurement errors.
• Diagnostic Capabilities: Detects and reports module failures, power supply issues, open input circuits, and fatal channel errors to the main controller’s diagnostic buffer.
• Ease of Use: Includes screw terminal connections for straightforward installation and maintenance.

Applications

The 1746-NT8 module is ideal for various industrial control systems, including:

• Temperature Control: Measures and controls temperatures in industrial furnaces, ovens, and kilns.
• Pressure Control: Measures and manages pressure in pipelines, tanks, and equipment.
• Flow Control: Measures and regulates flow rates in pipelines and gas systems.
• Level Control: Measures and controls liquid levels in tanks and reservoirs.

Industries

The 1746-NT8 module is used across multiple industries, including:

• Chemical
• Manufacturing
• Oil and Gas
• Power Generation