1756-IR12 | Allen-Bradley ControlLogix Non-Isolated RTD Input, 12 Points

The 1756-IR12 is a 12-channel analog input module designed for use with 3-wire RTD sensors in the Allen-Bradley ControlLogix system. It is primarily used for accurate temperature measurement in industrial automation environments. This module supports various input resistance ranges, making it compatible with a wide range of RTD types. Its 24-bit resolution ensures precise analog-to-digital conversion for each channel. Additional features include sensor offset, wire-off detection, and diagnostic alarms for out-of-range conditions, making it highly reliable in critical applications.

Yes, the 1756-IR12 is hot-swappable, meaning it can be inserted or removed from a powered chassis without shutting down the ControlLogix system. This functionality is particularly useful during maintenance or module replacement, reducing system downtime. Safety guidelines must still be followed, including grounding procedures and ensuring no live wiring is touched. Hot-swapping is a key feature in modular automation systems that require high availability. The module automatically reinitializes upon insertion and communicates with the controller if properly configured.

The 1756-IR12 consumes approximately 200 mA at 5.1 VDC and 150 mA at 24 VDC. It has a power dissipation of 2.7 Watts and thermal dissipation of around 9.2 BTU/hr. This consumption level is moderate for a high-resolution 12-channel input module. These values should be considered when designing the chassis power budget and selecting a compatible power supply. Effective heat dissipation is also important to maintain system reliability.

The module accepts passive analog signals from 3-wire RTD sensors, which convert temperature into changes in resistance. It does not support voltage or current signals — it is dedicated solely to resistance-based temperature sensing. The 3-wire configuration helps compensate for lead wire resistance, improving measurement accuracy. Supported sensors include popular types like PT100 and PT1000. Proper sensor configuration is done via software settings in the ControlLogix system.

As of the latest information from Rockwell Automation, the 1756-IR12 remains an active product in the ControlLogix portfolio. However, given the frequent product lifecycle updates, it is advisable to consult the Rockwell Automation Product Compatibility and Download Center (PCDC) to confirm current availability. Even if discontinued, Rockwell typically offers replacement models with backward compatibility. System designers should plan for long-term support by reviewing the lifecycle status and considering spare parts. Availability may also depend on region and distributor inventory levels.