1756-IT6I ControlLogix Temperature Sensing Analog Input Module

Description

The 1756-IT6I is a high-precision, individually isolated thermocouple input module designed for use within ControlLogix systems. It supports various thermocouple types, providing reliable temperature measurements with robust noise rejection and overvoltage protection.

Features

• Six Individually Isolated Thermocouple Inputs: Supports thermocouple types B, E, J, K, R, S, T, N, C, D, L (TXK/XK).
• Cold Junction Compensation (CJC): One built-in CJC sensor.
• High-Resolution Measurement: Provides a resolution of 16 bits with high-resolution ranges.
• Thermocouple Linearization: Follows ITS-90 standards for accuracy.
• Noise Rejection: 60 dB at 60 Hz normal mode, 120 dB at 60 Hz and 100 dB at 50 Hz common mode.
• Open Circuit Detection: Detects open circuits within 2 seconds.

Specifications

• Input Range: -12…78 mV (standard), -12…30 mV (high-resolution).
• Resolution:
  • Standard Range: 1.4 µV/bit (typical)
  • High-Resolution Range: 0.7 µV/bit
• Current Draw:
  • 5.1V: 250 mA
  • 24V: 125 mA
• Power Dissipation:
  • Maximum: 4.3 W
  • Thermal: 14.66 BTU/hr
• Input Impedance: >10 MΩ
• Overvoltage Protection: Maximum of 120V AC/DC
• Channel Bandwidth: 15 Hz (-3 dB)
• Settling Time: Less than 80 ms to 5% of full scale
• Calibrated Accuracy @ 25°C: Better than 0.1% of range
• Calibration Interval: 6 months
• CJC Sensor Accuracy:
  • Local: ±0.3…3.2 °C
  • Remote: ±0.3 °C
• Offset Drift: 0.5 µV/°C
• Gain Drift with Temperature:
  • Nominal: 65 ppm/°C
  • Maximum: 80 ppm/°C
• Module Error: 0.5% of range
• Module Scan Time:
  • Floating Point (millivolt): 25 ms min
  • Floating Point (temperature): 50 ms min
  • Integer (millivolt): 10 ms min

Data and Conversion

• Data Format: Integer mode (left justified, 2's complement) IEEE 32-bit floating point
• Conversion Method: Sigma-Delta
• Isolation Voltage: 250V (continuous), basic insulation type, input channels-to-backplane, and input channel-to-channel; routine tested at 1350V AC for 2 seconds.

Physical and Environmental

• Removable Terminal Block: 1756-TBNH, 1756-TBSH
• Slot Width: 1
• Wire Category: 2
• Temperature Code:
  • North American: T4A
  • IEC: T4
• Enclosure Type: None (open-style)
• Relative Humidity: 5…95% non-condensing
• Vibration Resistance: 2 g @ 10…500 Hz (IEC 60068-2-6, Test Fc)
• Shock Resistance:
  • Operating: 30 g (IEC 60068-2-27, Test Ea)
  • Nonoperating: 50 g (IEC 60068-2-27, Test Ea)
• Emissions Compliance: CISPR 11, Class A