Purchase now: Allen-Bradley 1756-IRT8I ControlLogix Isolated Temperature Module
Atlantechdrives provides you the 1756-IRT8I, an ultra-precise 8-channel temperature input module with individual point-to-point isolation. This module is the premier choice for chemical processing, power plants, and laboratory environments where the highest accuracy and signal protection are required. It supports both RTD (Resistance Temperature Detector) and Thermocouple sensors on the same module.
- Channels: 8 Individually Isolated Inputs
- Sensor Types: RTD (Pt100, Pt200, etc.) and Thermocouple (J, K, T, R, S, B, N, L, C)
- Resolution: Up to 24-bit (Analog-to-Digital Converter)
- Isolation: 100% Channel-to-Channel and Channel-to-Backplane
- CJC: Integrated Cold Junction Compensation
Technical Superiority: The Gold Standard for Thermal Accuracy
The 1756-IRT8I is engineered for stability. By providing individual isolation for every channel, it completely eliminates ground loops and prevents electrical noise from one sensor from affecting the others. This is critical when sensors are located in different parts of a large furnace or reactor. The module uses a 24-bit sigma-delta converter, providing incredible resolution that can detect temperature changes as small as 0.01 degrees. It also features integrated Cold Junction Compensation (CJC) for thermocouples, ensuring that environmental changes at the terminal block do not skew your readings. The 1756-IRT8I is the definitive solution for high-stakes process control where precision translates directly to product quality and safety.
Installation Advice: CJC and Wiring Best Practices
When wiring the 1756-IRT8I, the use of the 1756-TBNH or TBSH terminal block is required, and for thermocouples, you **must** use the CJC thermistors included with the module. These thermistors must be installed in the specific terminals as directed by the manual to ensure accurate reference temperature readings. Always use the appropriate compensation wire for thermocouples; using standard copper wire will create secondary junctions and result in large measurement errors. For RTDs, we highly recommend 4-wire configurations to eliminate the effect of lead-wire resistance, especially for long-distance runs of more than 50 meters.
Maintenance and Calibration Integrity
The 1756-IRT8I is a precision instrument and should be treated as such. Maintenance involves an annual software-based calibration check to ensure the module remains within its laboratory-grade specifications. Check the «Module Info» tab in Studio 5000 for «Open Wire» or «Over Range» faults, which usually indicate a failing sensor or a loose terminal. Periodically verify that the terminal block screws are not over-tightened on the fragile CJC thermistor leads. In high-vibration environments, using the spring-clamp 1756-TBSH block can help maintain constant pressure on the sensor leads, preventing intermittent signal drift.
FAQs
Q: Can I mix RTDs and Thermocouples on one 1756-IRT8I?
A: Yes, each of the 8 isolated channels can be independently configured for either an RTD or a Thermocouple.
Q: Does the 1756-IRT8I require external power?
A: It draws its operating power from the ControlLogix backplane and does not require a separate field power supply.
Do you need more references from this brand? Explore our full catalog of Allen-Bradley here.
For high-density RTD and thermocouple sensing, this isolated module provides superior precision when managed by a ControlLogix 5573 processor.
