Product Overview
Temperature measurement in industrial processes demands accuracy you can trust. The Allen-Bradley 1756-IT6I2 delivers exactly that as an enhanced thermocouple analog input module for the ControlLogix platform. With six individually isolated thermocouple inputs and two cold junction compensation (CJC) sensors, this module handles demanding temperature monitoring tasks across oil, gas, and automation environments.
The 1756-IT6I2 supports thermocouple types B, C, D, E, J, K, L, N, R, S, and T, giving engineers flexibility across a wide range of temperature applications. Whether you are upgrading an existing ControlLogix system or building a new installation, this module integrates directly into any ControlLogix chassis.
Technical Specifications
Input Resolution and Accuracy
The 1756-IT6I2 offers 16-bit resolution across two input ranges. The high-resolution range of -12 to 30 mV delivers 0.7 microvolts per bit, while the standard range of -12 to 78 mV provides 1.4 microvolts per bit. This level of precision matters when small temperature deviations can affect product quality or process safety.
Both local and remote CJC sensors maintain accuracy of +/- 0.3 degrees Celsius. Thermocouple linearization follows the ITS-90 standard, and offset drift stays at 0.5 microvolts per degree Celsius.
Isolation and Protection
Each of the six thermocouple inputs is individually isolated, preventing ground loops and signal interference between channels. Input impedance exceeds 10 megohms, and the module provides overvoltage protection rated at 120 Volts AC/DC.
Noise Rejection and Filtering
Normal-mode noise rejection reaches 60 dB at 60 Hertz, while common-mode rejection is a minimum of 160 dB when tested at 600 Volts AC at 60 Hertz with 100 ohms differential resistance. A notch filter and digital filter (available in floating-point mode) further clean incoming signals.
Data Format and Scan Time
Users can select integer mode (left-justified, 2s complement) or IEEE 32-bit floating point. Module scan time ranges from 10 ms minimum in integer millivolt mode to 50 ms minimum in floating-point temperature mode.
Comparison with Standard Thermocouple Modules
| Feature | 1756-IT6I2 | Standard Thermocouple Module |
|---|---|---|
| Inputs | 6 isolated + 2 CJC | Typically 4-8 non-isolated |
| Resolution | 16-bit | Often 12-14 bit |
| CJC Accuracy | +/- 0.3 degrees C | Varies, often +/- 0.5 degrees C |
| Isolation | Per-channel | Usually bank-isolated |
| Data Format | Integer or floating point | Limited options |
The 1756-IT6I2 stands out for applications requiring channel-to-channel isolation and high-resolution measurements.
Installation and Integration
The 1756-IT6I2 installs into any ControlLogix chassis using a removable terminal block. The compatible RTB is the 1756-TBNH. The module communicates with ControlLogix processors and communication modules, supporting both stand-alone and distributed I/O architectures.
Integration Note
When wiring thermocouples into a ControlLogix system, confirm cable types and any required connection modules with your supplier. Proper shielding and grounding practices are essential for maintaining measurement accuracy.
Applications
Oil and Gas Processing
Temperature monitoring in distillation columns, reactors, and pipeline systems benefits from the module’s isolation and accuracy. The 1756-IT6I2 handles multiple thermocouple types, making it suitable for diverse measurement points.
Industrial Furnaces and Ovens
High-temperature processes using type K, R, or S thermocouples rely on precise linearization and cold junction compensation. The module’s 16-bit resolution captures small temperature changes that affect product quality.
Power Generation
Turbine and boiler monitoring applications require reliable temperature data. The 1756-IT6I2 provides real-time sampling, wire-off detection, and process alarms to support safe operation.
Maintenance and Reliability
Periodic inspection of terminal connections and thermocouple wiring helps maintain measurement accuracy. The module’s open-circuit detection identifies failed sensors within 2 seconds, allowing quick troubleshooting. Environmental considerations include maintaining proper panel ventilation, as thermal dissipation reaches 15.7 BTU/hour.
Please verify current lifecycle status and availability with Oil AutoTech before ordering.
Why Choose Oil AutoTech
Oil AutoTech specializes in fast-dispatch spares for oil, gas, and industrial automation applications. Our team provides hands-on technical selection help to ensure you get the right module for your system. With quick worldwide delivery, we keep your operations running.
Contact Oil AutoTech today for pricing and availability.
