Allen-Bradley 1756-IA16 120V AC Input Module 16 Points

1756-IA16 ControlLogix AC Input Module Overview

The Allen-Bradley 1756-IA16 provides a robust interface for AC-powered discrete field devices. This module is a core component of the ControlLogix system from Allen-Bradley. It reads 16 independent input points from devices like pushbuttons, limit switches, and proximity sensors. Its nominal voltage is 120V AC, but it operates smoothly across a wide range from 74V to 132V AC at 47-63 Hz. This flexibility makes it suitable for global industrial environments with varying power conditions.

Technical Specifications and Performance

This I/O module is designed with two isolated groups, each containing eight input channels. This group isolation helps reduce electrical noise and enhances signal integrity. The 1756-IA16 module draws 100 mA from the 5.1V DC backplane and just 2 mA from the 24V DC supply, resulting in a total backplane power of only 0.58 W. Meanwhile, its maximum power dissipation reaches 5.8 W at 60 °C, equating to 18.41 BTU/hr of thermal energy.

The on-state current requirements are clearly defined for reliable operation. Specifically, it needs a minimum of 5 mA at 79V AC and handles a maximum of 13 mA at 132V AC. In the off-state, the leakage current stays below 2.5 mA, preventing false triggers. Additionally, the module's input delay is programmable via user-selectable filters. For OFF to ON transitions, you can choose a filter time of 1 ms or 2 ms, while ON to OFF transitions offer 9 ms or 18 ms options. These filters effectively debounce switch contacts and reject high-frequency noise.

Furthermore, the module provides a cyclic update time ranging from 200 µs to 750 ms, depending on the chassis slot and system configuration. This ensures timely data delivery to the controller. Each input channel includes a dedicated status LED on the front face, providing instant visual feedback for troubleshooting.

Mechanical and Environmental Specifications

The 1756-IA16 is built to withstand harsh industrial conditions. It operates within a temperature range of 0 to 60 °C (32 to 140 °F) and can endure storage temperatures from -40 to 85 °C. Relative humidity from 5% to 95% (non-condensing) is acceptable during operation. Moreover, the module holds a vibration resistance of 2 G at 10-500 Hz and a shock rating of 30 G, ensuring durability in high-vibration environments like manufacturing floors and processing plants. Its open-style enclosure requires installation within a properly rated industrial control panel.

Installation Guidelines

Installing the 1756-IA16 is straightforward and follows standard ControlLogix practices. First, ensure the chassis is powered off before inserting or removing any module. Align the module with the chosen slot in the ControlLogix chassis and slide it firmly until the locking tab clicks into place. Next, attach a compatible removable terminal block (RTB), such as the 1756-TBNH (screw-type) or 1756-TBSH (spring-clamp type), to the module's front connector. Wire your AC field devices to the terminal block according to the pinout diagram, ensuring correct polarity and proper strain relief. Finally, apply power to the chassis and verify that the module's status LEDs illuminate correctly. The module automatically communicates with the controller via the backplane, requiring no manual addressing.

Packaging List

Your shipment for the 1756-IA16 includes the following items:

• One Allen-Bradley 1756-IA16 ControlLogix AC Input Module

• One removable terminal block housing (either 1756-TBNH or 1756-TBSH, depending on stock)

• One product documentation flyer with basic connection diagrams

• Anti-static packaging for safe transport

Shipping Method

All orders are dispatched via FedEx, UPS, or DHL with full tracking and insurance coverage.

Frequently Asked Questions (FAQ)

1. What is the difference between the 1756-IA16 and the 1756-IA32?
The 1756-IA16 offers 16 input points, while the 1756-IA32 provides 32 points. Both are AC input modules with similar voltage ranges, but the IA32 has four groups of eight inputs and draws slightly more backplane current.

2. Can I use the 1756-IA16 with 240V AC signals?
No, the 1756-IA16 is rated for a maximum operating voltage of 132V AC. Using it with 240V AC will damage the module. For higher voltages, consider the 1756-IA8I or other high-voltage AC input modules.

3. Which terminal block is compatible with this module?
The 1756-IA16 works with either the 1756-TBNH (screw terminal) or 1756-TBSH (spring-clamp) removable terminal blocks. Both are sold separately or may be included with your order.

4. How do I select the input filter time for my application?
You configure the filter time via the ControlLogix controller's I/O configuration tree in Studio 5000 Logix Designer. Choose 1 ms or 2 ms for fast OFF-to-ON response, or 9 ms and 18 ms for ON-to-OFF transitions to reject noise.

5. What happens if the input current exceeds 13 mA?
Exceeding 13 mA on-state current may cause overheating and reduce the module's lifespan. Ensure your field devices meet the 5-13 mA specification at the applied voltage to maintain reliable operation.