Allen-Bradley 1794-IM16 Flex I/O 16-Point 240V AC Digital Input Module

Product Overview

The 1794-IM16 provides a high-density, 16-point discrete interface for Allen-Bradley Flex I/O systems, specifically designed to handle 240V AC input signals. This module functions as a critical bridge between high-voltage field devices—such as limit switches, motor starter auxiliary contacts, and pilot lights—and the programmable controller. We supply this module as 100% Brand New original equipment, ensuring long-term dielectric stability and signal precision for your distributed I/O network.

Technical Specifications

Engineering Advantages

• High-Voltage Interface Integration: The 1794-IM16 eliminates the need for interposing relays when monitoring 240V AC circuits. It accepts high-voltage field signals directly, reducing cabinet wiring complexity and lowering total hardware costs.

• Modular Space Efficiency: As part of the Flex I/O family, this module utilizes a small footprint. It enables engineers to deploy 16 points of high-voltage sensing in tight enclosures where traditional rack-based I/O would not fit.

• Rapid Installation and Maintenance: The module snaps onto a variety of 1794 terminal bases (such as the 1794-TB3 or 1794-TB3S). This "Removal and Insertion Under Power" (RIUP) capability allows maintenance teams to swap modules without disrupting the FlexBus power or existing field wiring.

• Enhanced Noise Immunity: Internal hardware filters manage the AC signal to prevent false triggers caused by electromagnetic interference (EMI) or contact bounce. This ensures the controller receives a stable logic state even in electrically noisy industrial environments.

FAQs

What terminal base should I use with the 1794-IM16?

The 1794-IM16 requires a compatible terminal base for field wiring. We recommend the 1794-TB3 or 1794-TB3S (spring clamp) to handle the 16-point density and 240V AC insulation requirements. Always verify the voltage rating of the terminal base before applying power.

Can the 1794-IM16 handle 120V AC signals?

No. The 1794-IM16 has an "On-State" voltage threshold starting at 159V AC. Applying 120V AC will not reliably trigger the input, leading to missed signals. For 120V AC applications, utilize the 1794-IA16 module instead.

Does this module require external power for the inputs?

The module draws its logic power (30 mA) from the FlexBus via the adapter. However, the field-side signals require an external 240V AC source to complete the circuit for the 16 input points.

Is it possible to mix different phases across the 16 input points?

While the module supports 16 points, they typically share common return paths depending on the terminal base used. Consult the specific wiring diagram for your 1794-TB base to ensure proper isolation and prevent phase-to-phase shorts.