Allen-Bradley 1794-IE8 Flex I/O Analog Input Module - 8 Channels

June 11, 2026 • 3 min read • wayne • Science

Product Summary

The Allen-Bradley 1794-IE8 Flex I/O analog input module delivers eight single-ended channels for precise current and voltage signal acquisition. It supports 0-20 mA, 4-20 mA, +/-10 VDC, and 0-10 VDC ranges. This module offers robust accuracy and easy integration into distributed control architectures.

Product Procurement & Buyer Guide

Selecting the Right Analog Input Module

Engineers need a reliable interface for field transmitters and process controllers. The 1794-IE8 provides eight non-isolated, user-configurable channels. Each channel accepts both current and voltage signals, simplifying inventory management. You can connect instruments like recorders and loop controllers directly.

Compatibility with Terminal Bases and Adapters

This module requires a compatible terminal base for mounting and wiring. Options include the 1794-TB2, 1794-TB3, 1794-TB3S, 1794-TB3T, and 1794-TB3TS. Only one base is needed per module. The 1794-IE8 works with Flex I/O communication adapters like Ethernet, ControlNet, and Remote I/O. This flexibility reduces system design complexity.

Power Supply and Installation Requirements

The module operates on a nominal 24 VDC supply. Its input range spans 10.5 to 31.2 VDC, including 5% AC ripple. It draws 60 mA from the external supply plus 60 mA from the FlexBus. Mounting options include DIN rail or direct panel mount. The open-style enclosure allows easy access.

Expert Technical Evaluation & Performance Review

Accuracy and Resolution Metrics

The 1794-IE8 achieves an absolute accuracy of 0.20% full scale at 25°C. Its resolution is 12 bits in unipolar mode and 11 bits plus sign in bipolar mode. Voltage resolution equals 2.56 mV/count unipolar and 5.13 mV/count bipolar. Current resolution is 5.13 µA/count. These specs ensure high-fidelity signal conversion.

Signal Conversion and Response

This module uses successive approximation conversion with a 16-bit, left-justified data format. The conversion rate is 256 µs per channel. Step response to 63% of final value takes 9.4 ms for voltage inputs and 18.2 ms for current inputs. Such fast response suits real-time process control.

Environmental and Electrical Tolerances

The module operates from -20 to 55°C and stores from -40 to 85°C. It withstands 5g vibration at 10 to 500 Hz and 30g operational shock. Power dissipation is 3.0 W at 31.2 VDC, with thermal dissipation of 10.2 BTU/hour. Isolation voltage is 50 V continuous. These ratings guarantee durability in harsh industrial settings.

Accuracy Drift and Overload Protection

Accuracy drift with temperature is minimal: 0.00428% full scale/°C for voltage and 0.00407% full scale/°C for current. The module tolerates continuous voltage overload up to 30 V and current overload up to 32 mA. Factory calibration eliminates the need for field adjustments, reducing maintenance downtime.