1794-IA16 | Allen-Bradley Flex I/O 16-Channel AC Input Module

Introduction: The Evolution of Discrete Input

Factory floors have changed dramatically over the last three decades. Early relay panels gave way to centralized PLC racks, and then to distributed I/O architectures that brought control closer to the machine. The Allen-Bradley Flex I/O family emerged from that shift, letting engineers place compact I/O blocks exactly where signals originate. The 1794-IA16 continues that tradition as a 16-channel AC input module built for real-world industrial voltage levels.

This module belongs to the Flex I/O product family and serves as an AC Input Module. It provides Sixteen (16) non-isolated input channels, making it a practical choice for panel builders who need dense AC sensing without excessive wiring runs.

Why the 1794-IA16 Fits Modern Retrofit Projects

Replacement and upgrade work often forces engineers to match existing field voltages. Many legacy machines still run AC pilot devices, limit switches, and pushbuttons at 120VAC nominal levels. The 1794-IA16 accepts an ON state voltage range of 74VAC to 132VAC, so it handles those signals directly. Its OFF state voltage maximum sits at 20VAC, which helps prevent false triggering from residual leakage.

Current characteristics matter just as much. The module draws a nominal input current of 12 mA at 120 Volts AC. Minimum ON state current is 5.49 mA, while maximum ON state current reaches 14.81 mA. These figures help technicians confirm that field devices supply enough current to energize each channel reliably.

Key Parameters at a Glance

Compatibility and Integration Points

The 1794-IA16 works with Flex I/O communication adapters, including ControlNet adapters (1794-ACN, 1794-ACNR, 1794-ACNR15), Ethernet adapters (1794-AENT, 1794-AENTR), and the Remote I/O adapter 1794-ASB. This flexibility lets you standardize on one input module across multiple network architectures.

Termination requires a compatible terminal base. Supported options include 1794-TB3, 1794-TB3S, 1794-TBN, 1794-TB3K, 1794-TB3SK, and 1794-TBNK. The terminal base also enables daisy-chain power connections, so power transfers between modules without separate supply wiring. That design shortens wire lengths and simplifies panel layout.

Power and Dissipation

The module receives power through the Flexbus at 20 mA. Maximum power dissipation is 6.4 Watts at 132 Volts AC. Plan panel thermal management around this figure when modules sit in dense enclosures.

Installation and Setup Guidance

Mount the module on DIN rail, then set the keyswitch to position 8. Wire size depends on the installed terminal base, so follow the base documentation for conductor selection. The enclosure type rating is None (open-style), meaning the module must live inside a protective cabinet.

Keep operating temperature between 0 to 55 C (32 to 131 F). Storage temperature spans -40 to 85 C (-40 to 185 F). The module withstands vibration of 5g at 10 to 500 Hz and operating shock of 30 g.

Maintenance and Reliability

Each channel carries a yellow status indicator, which makes troubleshooting fast. A technician can confirm input energization without a multimeter. Inspect terminal connections periodically and verify that cabinet cooling keeps ambient conditions inside the rated range. Because the module is open-style, dust and moisture control depend on the enclosure, not the module itself.

Selection Checklist Before You Buy

Confirm your field voltage falls within the 74VAC to 132VAC ON state window. Verify that your chosen terminal base appears on the compatible list. Check that your communication adapter matches your network. SpareTechPLC stocks industrial automation parts and can help you verify availability before ordering.

Please verify current lifecycle status and availability with SpareTechPLC before ordering.