Allen Bradley 1771-IR Resistance Temperature Detector (RTD) Input Module

The Allen-Bradley 1771-IR Resistance Temperature Detector (RTD) Input Module is a specialized component designed for precise temperature measurement in industrial automation systems. It seamlessly integrates with Allen-Bradley’s PLC-5 series, facilitating accurate monitoring and control of temperature-dependent processes.

Key Features

• Input Channels: Equipped with six three-wire RTD input channels, allowing simultaneous monitoring of multiple temperature points.
• Sensor Compatibility: Supports 100-ohm platinum (α = 0.00385) and 10-ohm copper (α = 0.00386) RTDs. Other sensor types can be utilized with readings reported in ohms.
• Measurement Units: Configurable to display temperature readings in degrees Celsius (°C), degrees Fahrenheit (°F), or resistance in ohms.
• Temperature Range:
  • Platinum RTDs: -200°C to +870°C (-328°F to +1598°F)
  • Copper RTDs: -200°C to +260°C (-328°F to +500°F)
• Resolution:
  • Platinum RTDs: 0.1°C (0.1°F)
  • Copper RTDs: 0.3°C (0.5°F)
• Data Formats: Offers natural binary, BCD actual temperature, or ohm readings for versatile data representation.
• Update Time: Completes a full scan of all six channels in 50 milliseconds, ensuring timely data acquisition.
• Auto-Calibration: Features automatic calibration to maintain measurement accuracy over time.
• Open Wire Detection: Incorporates open wire detection to identify and alert users to potential wiring issues.

Technical Specifications

• Backplane Current Draw: 800 mA at 5V DC
• Power Dissipation: 4.75 Watts
• Signal Delay:
  • On-state (DC): 10 milliseconds
  • Off-state (DC): 50 milliseconds
  • Off-state (AC): 45 milliseconds (±15 ms)
• Input Overvoltage Protection: Withstands continuous exposure up to 120V RMS
• Isolation:
  • Dielectric Test: 1000V peak channel-to-channel and channel-to-backplane for 1 second
  • Common Mode Rejection: 120 dB at 60 Hz up to 1000V peak
• Operating Temperature: 0°C to 60°C (32°F to 140°F)
• Storage Temperature: -40°C to 85°C (-40°F to 185°F)
• Relative Humidity: 5% to 95% non-condensing

Installation and Compatibility

The 1771-IR module is designed for rack-mounting within the 1771 I/O chassis, compatible with various Allen-Bradley PLC systems, including PLC-2, PLC-3, and PLC-5 controllers. It utilizes the 1771-WF wiring arm for secure and efficient field wiring connections. Keying positions are set between 10 and 12 or between 28 and 30 to ensure correct module placement.

Applications

This module is ideal for industrial applications requiring precise temperature monitoring and control, such as chemical processing, food and beverage production, and manufacturing environments where temperature regulation is critical to product quality and safety.

Certifications

• UL Listed
• CSA Certified
• CE Compliant

These certifications affirm the module’s adherence to international safety and performance standards, ensuring reliable operation in diverse industrial settings.