Allen-Bradley 1756-IR12 ControlLogix 12-Channel RTD Analog Input Module

Product Overview

The Allen-Bradley 1756-IR12 provides high-density temperature sensing for the ControlLogix platform. This module interfaces directly with up to 12 3-wire Resistance Temperature Detectors (RTDs) or other resistance-based sensors. It converts low-level analog resistance signals into 24-bit digital data for precise process control in chemical, power, and food processing industries. We supply this module as 100% Brand New and Original, ensuring factory-sealed integrity for your high-availability ControlLogix chassis.

Technical Specifications

Engineering Advantages

• High-Density Thermal Mapping: The 12-channel architecture allows for extensive temperature monitoring across a single chassis slot. This reduces the total number of modules required in large-scale thermal applications, saving valuable backplane space.

• Superior 24-Bit Precision: The 24-bit resolution detects minute resistance changes. This sensitivity ensures accurate temperature feedback even in applications with very narrow process windows, improving overall product quality and safety.

• Lead-Wire Compensation: The module specifically supports 3-wire RTD configurations. It automatically compensates for the resistance of the lead wires, ensuring that the sensor cable length does not skew your temperature readings.

• Robust Electrical Protection: A 250V continuous isolation voltage protects the controller logic from field-side electrical surges. This isolation barrier prevents ground loops and minimizes the impact of electromagnetic interference (EMI) on the analog signal integrity.

FAQs

• Can the 1756-IR12 support 2-wire or 4-wire RTDs? This module primarily targets 3-wire RTD connections to utilize its internal compensation circuitry. While you can wire other types by following specific terminal jumpering procedures, 3-wire sensors provide the best balance of accuracy and lead-wire compensation for this hardware.

• What resistance ranges does the module support? The 1756-IR12 offers four user-selectable ranges: 1–500 Ω, 2–1000 Ω, 4–2000 Ω, and 8–4000 Ω. This allows you to interface with a wide variety of platinum, nickel, copper, or moly RTD elements.

• How do the Status LEDs assist in troubleshooting? The module features a front-panel display that indicates the health of the module and the status of individual channels. If a sensor wire breaks or a channel exceeds its range, the LED diagnostics alert maintenance personnel immediately, slashing mean time to repair (MTTR).

• Does this module require a specific Removable Terminal Block (RTB)? Yes. You must use a compatible 36-pin RTB (such as the 1756-TBCH or 1756-TBSH) to connect field wiring. We recommend using shielded twisted-pair cable to maintain the high signal-to-noise ratio provided by the 24-bit converter.