Product Overview

The Allen-Bradley 1756-OA16I is a high-performance discrete output module designed for the ControlLogix® platform, providing 16 channels of AC switching capability. A critical differentiator for this "I" version is that every output point is individually isolated, allowing for the control of 16 separate AC loads that may be powered by different phases or distinct power sources. Operating across a wide voltage range of 75V to 265V AC, it is an ideal solution for interfacing with solenoids, motor starters, and actuators in complex industrial environments where signal separation is paramount.

This single-slot module integrates seamlessly into any standard 1756 ControlLogix chassis, supporting both local controller placement and remote I/O configurations via EtherNet/IP or ControlNet adapters. It utilizes a Triac-based switching architecture to manage 120/240V AC nominal loads with high reliability. To ensure system uptime, the module allows for point-level configuration of "Fault States," enabling users to define whether an output should turn on, shut off, or hold its last state during a communication loss.

Advanced Electrical Performance and Safety

The 1756-OA16I is engineered for rugged reliability, featuring a 250V continuous isolation rating between individual channels and from the backplane. It is capable of handling significant inrush currents (up to 20A per point for 43ms), which is essential when starting inductive loads like heavy-duty relays or valves. While the module does not include internal fuses, its robust dielectric testing (1350V AC for 2 seconds) ensures it can withstand the electrical transients common in heavy manufacturing and power generation sectors.

For physical connectivity, the 1756-OA16I utilizes a 36-pin Removable Terminal Block (RTB), specifically the 1756-TBCH or 1756-TBS6H. This allows for rapid module replacement without the need to disconnect field wiring, significantly reducing Mean Time to Repair (MTTR). The module's front panel includes 16 status LEDs, providing immediate visual feedback for the operational state of each isolated output.

Technical Specifications

• Manufacturer: Allen-Bradley (Rockwell Automation)

• Model Number: 1756-OA16I

• Outputs: 16 Individually Isolated Channels

• Operating Voltage: 75–265V AC @ 47–63 Hz

• Backplane Current: 300mA @ 5.1V DC; 2.5mA @ 24V DC

• Power Dissipation: 5.5 Watts (Maximum)

• Continuous Current per Point: 2A @ 30°C (Derated to 1A @ 60°C)

• Maximum Inrush Current: 20A per point for 43ms

• Isolation Voltage: 250V (Continuous), Basic Insulation Type

• Response Time (On/Off): 9.3ms @ 60 Hz; 11ms @ 50 Hz

• Chassis Compatibility: 1756-A4, A7, A10, A13, A17

• Environmental Rating: 0–60°C (Operating); 5–95% RH (Non-condensing)

• Dimensions: 21.5 x 17.5 x 5 cm

• Weight: 0.44 kg

Core Functional Advantages

• Point-to-Point Isolation: Eliminates the need for external interposing relays when dealing with different AC phases or separate power grids across 16 channels.

• High Current Capacity: Supports up to 2A per channel at lower ambient temperatures, making it one of the most robust AC modules in the ControlLogix lineup.

• Configurable Fault Modes: Software-selectable behavior for each point during system failures to ensure process safety.

• Industrial Hardening: Designed to withstand 30G of operational shock and severe vibration, ensuring longevity in high-motion applications.