Allen Bradley 1756-IR6I ControlLogix Series 6-Channel Isolated RTD Analog Input Module

Product Description

The 1756-IR6I module from Allen Bradley’s ControlLogix series is a six-channel isolated analog input unit designed for precision temperature measurement using RTD sensors. Each input is electrically isolated, ensuring accurate signal acquisition and noise immunity in demanding industrial environments. With high-resolution data conversion, configurable scan times, and compatibility with multiple RTD types, it is ideal for advanced process control applications.

Technical Specifications

• Manufacturer: Allen Bradley

• Product Line: ControlLogix

• Part Number: 1756-IR6I

• Category: PLC Analog Input Module

• Module Type: Isolated RTD Analog Input

• Inputs: 6 isolated RTD channels

• Compatible RTD Types:

• Platinum: 100, 200, 500, 1000 Ω (α = 385, α = 3916)

• Nickel: 100, 120, 200, 500 Ω (α = 618, α = 672)

• Resolution: 16-bit

• 1–487 Ω: 7.7 mΩ/bit

• 2–1000 Ω: 15 mΩ/bit

• 4–2000 Ω: 30 mΩ/bit

• 8–4020 Ω: 60 mΩ/bit

• Input Range: 1–487 Ω, 2–1000 Ω, 4–2000 Ω, 8–4000 Ω

• Module Scan Time:

• 25 ms minimum (floating point, ohms)

• 50 ms minimum (floating point, temperature)

• 10 ms minimum (integer, ohms)

• Data Format: Integer (left-justified, 2’s complement) or IEEE 32-bit floating point

• Maximum Input Current (Off-State): 2.75 mA

• Maximum Operating Current: 1.2 mA @ 30 VAC, 60 Hz

• Backplane Current Draw:

• 250 mA @ 5 VDC

• 125 mA @ 24 VDC

• 2 mA @ 24 VDC (auxiliary)

• Power Dissipation: 4.3 W @ 60 °C (140 °F)

• Isolation Voltage: 50 V continuous

• Removable Terminal Blocks: 1756-TBNH, 1756-TBSH

• Weight: 0.63 lbs (0.28 kg)

• Enclosure Type: Open-style

Key Features

• Six isolated RTD inputs for precise temperature measurement.

• High-resolution conversion with multiple input ranges.

• Configurable scan times for flexible performance.

• Supports platinum and nickel RTDs with different alpha coefficients.

• Compact single-slot design for ControlLogix chassis.

Application Scenarios

• Process industries requiring accurate temperature monitoring.

• Advanced automation systems with multiple RTD sensors.

• Distributed control systems needing isolated analog inputs.

FAQ

Q: What types of RTDs are supported by the 1756-IR6I?   A: It supports platinum (100–1000 Ω) and nickel (100–500 Ω) RTDs with various alpha coefficients.

Q: What is the resolution of the module?  A: Resolution varies by input range, from 7.7 mΩ/bit at 487 Ω to 60 mΩ/bit at 4020 Ω.

Q: How does this compare to the 1756-IR6?  A: The 1756-IR6I provides isolated inputs, while the 1756-IR6 does not, making the IR6I more suitable for noise-sensitive applications.