Allen Bradley Resistance-Temperature Detector Input Module 1771-IR /A

Allen-Bradley 1771-IR/A RTD Input Module

The Allen-Bradley 1771-IR/A is a Resistance Temperature Detector (RTD) input module designed for integration with PLC-5 systems. It facilitates precise temperature monitoring by converting analog signals from RTDs into digital data for processing within the PLC framework.

Key Features

• Six RTD Input Channels: Accommodates up to six three-wire RTD sensors, enabling simultaneous temperature measurements across multiple points.
• Wide Sensor Compatibility: Supports 100-ohm platinum RTDs (α = 0.00385) and 10-ohm copper RTDs (α = 0.00386). Other RTD types can be utilized with resistance readings provided in ohms.
• Flexible Measurement Units: Offers temperature readings in both Celsius and Fahrenheit, as well as resistance measurements in ohms with resolutions of 10 milliohms or 30 milliohms.
• Extensive Temperature Range: Measures temperatures from -200°C to +870°C (-328°F to 1598°F) for platinum sensors and -200°C to +260°C (-328°F to +500°F) for copper sensors.
• High Resolution: Provides a resolution of 0.1°C (0.1°F) for platinum RTDs and 0.3°C (0.5°F) for copper RTDs, ensuring accurate temperature readings.
• Integrated Sensor Excitation: Supplies a constant 1 mA current to each sensor, eliminating the need for external excitation sources.
• Robust Input Isolation: Features 1000V peak isolation between channels and between each channel and the backplane, enhancing system safety and reliability.
• Comprehensive Fault Detection: Includes open RTD detection with a response time of less than 0.5 seconds, aiding in prompt identification of sensor issues.

Technical Specifications

• Backplane Current Consumption: 800 mA at 5V DC
• Power Dissipation: 4.75 W maximum
• Thermal Dissipation: 16.2 BTU/hr
• Signal Delays:
  • DC On-State: 10 ms
  • DC Off-State: 50 ms
  • AC On-State: 45 ms ± 15 ms
• Environmental Conditions:
  • 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/A module is compatible with various Allen-Bradley I/O chassis, including models 1771-A1B, 1771-A2B, 1771-A3B, and 1771-A4B. It utilizes the 1771-WF wiring arm for field connections and is keyed between positions 10 and 12 or between 28 and 30 to ensure correct installation.

Applications

Ideal for industrial process control, the 1771-IR/A module is used in applications requiring accurate temperature monitoring and control, such as manufacturing processes, HVAC systems, and other environments where precise thermal management is critical.

By integrating the Allen-Bradley 1771-IR/A RTD Input Module into your PLC system, you can achieve reliable and accurate temperature measurements essential for maintaining optimal process conditions.