1794-IR8

Overview

The 1794-IR8 is an Allen-Bradley FLEX I/O RTD input module with 8 channels, designed for precise resistance temperature detector (RTD) measurements in distributed control systems.

Module Identity

• Model: 1794-IR8

• Product Type: RTD Input Module

• Manufacturer: Allen-Bradley Rockwell

• Number of Inputs: 8 channels

• Module Location: Cat. No. 1794-TB2, -TB3, -TB3S, -TB3T, and -TB3TS terminal base units

Input Specifications

• Nominal Input Ranges: 1 to 433 Ω

• RTD Excitation Current: 718.36 µA

• Resolution: 16 bits across 435 Ω

Accuracy

• Normal Mode: 0.05% full scale (max) without calibration, at low humidity

• Enhanced Mode: 0.01% full scale (typical)

Electrical Characteristics

• Isolation Voltage: Tested at 850 V DC for 1 s (inputs and user power to logic side)

• Data Format: 16-bit 2’s complement or offset binary (unipolar)

• Channel Bandwidth: 0–2.62 Hz (-3 dB)

• Flexbus Current: 20 mA

• Power Dissipation: 3.0 W maximum @ 31.2 V DC

• Thermal Dissipation (max): 10.2 BTU/hr @ 31.2 V DC

Indicators

• Status: 1 red/green power status indicator

Physical Data

• Weight: 0.25 kg

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