1756-OB16I | Allen-Bradley Isolated DC Output Module Supplier

What Is the 1756-OB16I?

When your control system demands reliable, isolated digital outputs, the 1756-OB16I from Allen-Bradley provides a robust solution. As part of the ControlLogix series, this isolated DC output module features 16 individually isolated points, each capable of handling 2 A at 30 °C or 1 A at 60 °C with linear derating. Its operating voltage range of 10-30 V DC supports both sinking and sourcing configurations, making it versatile for various industrial loads.

With a maximum power dissipation of 3.6 W at 60 °C, the 1756-OB16I minimizes energy waste and reduces cooling costs over time. This cost-efficiency is critical for facilities running multiple modules in tight enclosures.

Key Features & Technical Specs

• 16 individually isolated outputs for independent load control.
• Operating voltage range: 10-30 V DC (12-24 V DC nominal).
• Output delay: 1 ms max off-to-on, 2 ms max on-to-off.
• Current per point: 2 A at 30 °C, 1 A at 60 °C (linear derating).
• Current per module: 8 A at 30 °C, 4 A at 60 °C (linear derating).
• Backplane current: 350 mA at 5 V, 3 mA at 24 V.
• Power dissipation: 3.6 W max at 60 °C.
• Isolation voltage: 50 V continuous between outputs.
• Compatible removable terminal blocks: 1756-TBCH, 1756-TBS6H.

Unique Insight: The 1756-OB16I’s individually isolated outputs allow each channel to be wired to different voltage sources, reducing the need for external isolation hardware. This simplifies design and lowers total system cost, especially in mixed-voltage applications.

Cost-Benefit & ROI Analysis

Investing in the 1756-OB16I delivers long-term value through reduced energy consumption and extended service life. Its linear derating from 2 A at 30 °C to 1 A at 60 °C ensures reliable operation even in warm environments, preventing premature failures that cause costly downtime. The low power dissipation of 3.6 W at 60 °C means less heat stress on surrounding components, potentially extending the life of your entire control panel.

Moreover, the module’s compatibility with standard 1756-TBCH and 1756-TBS6H terminal blocks simplifies installation and maintenance, reducing labor costs. By choosing the 1756-OB16I, you avoid the expense of external isolation modules and minimize spare parts inventory.

Applications & Use Cases

In manufacturing lines that control solenoids, relays, and indicator lamps, the 1756-OB16I provides the isolated outputs needed to protect sensitive logic circuits. Its 16-point configuration suits medium-density I/O requirements, while the individual isolation allows mixing of voltage sources without ground loops. For example, in a packaging machine, you can drive 24 V DC solenoids on one channel and 12 V DC indicators on another, all from the same module.

Additionally, the module’s configurable safe-state behavior (hold last state, on, or off) during controller faults enhances process safety and reduces scrap, directly improving operational ROI.

Installation & Setup Guide

Installing the 1756-OB16I is straightforward. Mount the module directly into any 1756 local or remote chassis. Use either the 1756-TBCH or 1756-TBS6H removable terminal block for signal wiring. Ensure the operating voltage stays within 10-30 V DC and observe the current derating curve: at 60 °C, limit each point to 1 A and the module to 4 A. For high-inductive loads, install external surge suppression to protect the outputs.

Always follow the manufacturer’s manual for wiring and configuration details. The module supports output data, listen-only, rack optimization, and scheduled output communication formats.

Maintenance & Reliability Tips

To maximize the 1756-OB16I’s lifespan, perform regular inspections of the terminal block connections and verify that the ambient temperature stays within the 0-60 °C operating range. Clean the module enclosure with a dry cloth; avoid solvents or contact cleaners. Periodically check that the backplane current (350 mA at 5 V, 3 mA at 24 V) remains within supply capacity. These simple steps prevent unexpected failures and keep your system running efficiently, supporting your cost-saving goals.

Compatibility & Integration

The 1756-OB16I integrates seamlessly with ControlLogix controllers and 1756 chassis. It supports multiple communication formats, including output data, listen-only, rack optimization, and scheduled output data. Use it in local or remote racks for distributed control. For detailed integration steps, refer to the ControlLogix system manual or contact Petro Auto Tech.

FAQs about 1756-OB16I

Q: What is the maximum current per point for the 1756-OB16I at 60 °C?

A: At 60 °C, the maximum current per point is 1 A, with linear derating from 2 A at 30 °C.

Q: Can the 1756-OB16I be used with different voltage sources on each channel?

A: Yes, because each output is individually isolated, you can wire different voltage sources (within 10-30 V DC) to each channel.

Q: What terminal blocks are compatible with the 1756-OB16I?

A: The module works with 1756-TBCH and 1756-TBS6H removable terminal blocks, both 36-pin.

Q: How does the 1756-OB16I handle output delays?

A: The off-to-on delay is 1 ms max, and the on-to-off delay is 2 ms max, ensuring fast response for time-critical applications.

Q: What is the isolation voltage between outputs on the 1756-OB16I?

A: The continuous isolation voltage between outputs is 50 V, allowing safe mixing of different voltage groups.

Product Support & Availability

The 1756-OB16I is available from Petro Auto Tech, an industrial automation parts supplier. Contact our team to verify current stock and lifecycle status before ordering. We offer fast shipping and dedicated support to help you integrate this module into your system.