1756-IRT8I Allen-Bradley ControlLogix 8 Channel Analog Module

Overview

The Allen-Bradley 1756-IRT8I is a high-performance ControlLogix analog input module, specifically designed for temperature sensing applications. It provides eight isolated input channels, configurable for RTD (Resistance Temperature Detector), Thermocouple, and millivolt signals. This module is ideal for industrial automation systems, ensuring accurate temperature measurements in real-time control applications.

Compatible with a variety of sensor types, the 1756-IRT8I supports multiple input ranges and offers exceptional resolution for precise data acquisition. It is optimized for use in SCADA, DCS, and HMI systems where reliable, high-resolution analog data is critical for process control and monitoring.

Technical Specifications

• Brand: Allen-Bradley
• Model: 1756-IRT8I
• Part Number: 1756-IRT8I
• Module Type: Analog RTD / Thermocouple / Millivolt Input
• No. of Inputs: 8 isolated channels
• Input Signal Types: RTD, Thermocouple, Millivolt
• Resolution: 24-bit
• Data Format: IEEE 32-bit floating point
• Input Range:
  • RTD (1 to 500 Ω, 2 to 1000 Ω, 4 to 2000 Ω, 8 to 4000 Ω)
  • Millivolt (-100 to 100 mV)
• Thermocouple Types: Type B, C, D, E, J, K, N, R, S, T, TXK/XK (L)
• RTD Excitation Current: 600 µA
• CJC Accuracy: ±0.3°C
• Thermocouple Linearization: ITS-90
• Power Dissipation (Max): 4.6 W
• Current Draw (24V): 150 mA
• Current Draw (5.1V): 200 mA
• Thermal Dissipation: 15.7 BTU/hr
• Module Scan Time: 1 ms
• Isolation Voltage: 250 V continuous
• Noise Rejection:
  • Normal Mode: 75 dB @ 60 Hz
  • Common Mode: 125 dB @ 60 Hz (1000 Ω differential)
• Open Circuit Detection:
  • Thermocouple: 2 sec
  • 3-Wire RTD: 2 sec
  • 4-Wire RTD: 5 sec

Ordering Information:

• Module: 1756-IRT8I
• Compatible RTB: 1756-TBCH, 1756-TBS6H
• Accessory: 1756-TBNH (Removable Terminal Block)

FAQ

• Q: Can I use this module with any RTD sensor?
  A: The module supports multiple RTD types, including Platinum (alpha=385, alpha=3916), Nickel, and Copper with various resistance values. Please ensure your RTD sensor matches the compatible specifications.
• Q: How accurate is the cold junction compensation (CJC)?
  A: The CJC has an accuracy of ±0.3°C, ensuring reliable thermocouple readings even in varying environmental conditions.
• Q: What is the maximum input voltage for millivolt signals?
  A: The module supports a range of -100 to 100 mV for millivolt signals.
• Q: How do I install this module?
  A: The module can be installed using a compatible removable terminal block (RTB), such as the 1756-TBS6H or 1756-TBCH.

Check official datasheet for more detailed information: ControlLogix and GuardLogix Controllers