Overview
Allen-Bradley 1756-IR6I is an analog isolated RTD input module designed for seamless integration into ControlLogix 1756 chassis. This module provides six individually isolated Resistance Temperature Detector (RTD) input channels with 16-bit resolution, enabling accurate and noise-immune temperature measurement across multiple sensor locations in a single compact slot.
Key Features
- Six Isolated RTD Inputs: Channel-to-channel isolation reduces noise and improves accuracy in multi-point temperature sensing applications.
- 16-Bit Resolution: Scales from 7.7 mΩ/bit to 60 mΩ/bit depending on selected input range.
- Configurable Input Ranges: Supports 1–487 Ω, 2–1,000 Ω, 4–2,000 Ω, and 8–4,000 Ω resistance ranges.
- Multiple RTD Support: Compatible with Pt100, Pt200, Pt500, Pt1000 (alpha=385 and 3916), Ni100, Ni120, and Cu10 sensors.
- Data Format Flexibility: Integer mode (16-bit) or IEEE 32-bit floating-point with temperature linearization, digital filtering, and process/rate alarms.
- Built-in Diagnostics: Underrange/overrange detection, notch filter for line-noise rejection, and real-time channel sampling.
Technical Specifications
- Input Channels: 6 isolated RTD/resistor inputs
- Resolution: 16-bit digital
- Input Ranges: 1–487 Ω | 2–1,000 Ω | 4–2,000 Ω | 8–4,000 Ω
- Resolution per Range: 7.7 mΩ/bit | 15 mΩ/bit | 30 mΩ/bit | 60 mΩ/bit
- Backplane Current (5.1 VDC): 250 mA typical
- Backplane Current (24 VDC): 125 mA typical
- Power Dissipation (Max): 4.3 W
- Operating Temperature: 0–60°C
- Scan Time (Resistance): 25 ms per channel
- Scan Time (Temperature): 50 ms per channel
- Physical Format: Single-slot ControlLogix module (20-pin connector)
- Terminal Block Options: 1756-TBNH or 1756-TBSH (removable)
- Certifications: UL, CE, CSA, RoHS compliant
Typical Applications
The 1756-IR6I excels in demanding environments requiring multi-point temperature monitoring. Common uses include:
- Process control and batch operations in food, chemical, and pharmaceutical industries
- Furnace and oven temperature mapping and regulation
- HVAC systems and thermal loop control
- Refrigeration and cold-chain monitoring
- Machine health monitoring and predictive maintenance
- Environmental chamber control and lab automation
Compatibility & Replacements
Compatible With
- ControlLogix 1756 chassis (all generations)
- Studio 5000 / RSLogix 5000 programming software
- EtherNet/IP industrial networks
- PROFINET gateways and bridges
- DeviceNet and ControlNet adapters
- All Logix5000-based controllers
Replaces / Drop-In Replacement For
- Earlier revisions of Allen-Bradley 1756-IR6I (Rev A and earlier)
- Verify exact firmware compatibility with your system integrator for legacy installations
Works With
- Software: Studio 5000 (v32+), RSLogix 5000, FactoryTalk View
- Protocols: EtherNet/IP, PROFINET, DeviceNet, ControlNet
- Backplane: ControlLogix 1756 I/O slot interface
- Sensors: Any 2-wire, 3-wire, or 4-wire RTD (Pt100, Pt1000, Ni100, Cu10, etc.)




