Allen-Bradley 1747-UIC USB to DH-485 Interface Converter — Product Introduction

Introduction

In the world of industrial automation, there is often a need to connect modern engineering tools with legacy equipment. The Allen-Bradley 1747-UIC (Universal Interface Converter) fulfills this crucial role by acting as a bridge between a computer’s USB port and devices that communicate over the DH-485 protocol. DH-485 is a legacy network protocol used by Allen-Bradley controllers such as SLC 500 processors and other older hardware, and the 1747-UIC enables modern laptops and PCs—most of which no longer have serial ports—to connect to these controllers for programming, monitoring, and troubleshooting.

This adapter is not simply a passive cable. It is an intelligent communication interface that handles protocol conversion internally, allowing seamless communication between the RS-232/USB world and the DH-485 network. For maintenance engineers, system integrators, and field technicians, the 1747-UIC is an indispensable tool that supports continued operation of legacy systems while still leveraging modern computing hardware.

Unlike communication modules or batteries that are permanently installed in a control system, the 1747-UIC is a portable, service-oriented device. It is designed to be used when configuration or diagnostic work is needed, and then disconnected when the task is complete.

Purpose and Role in Automation Systems

The 1747-UIC serves a very specific but essential purpose: to provide a USB interface for DH-485 networks. Many production facilities continue to operate equipment that relies on DH-485 because it is proven, reliable, and cost-effective. However, the phasing out of older desktop PCs with built-in serial ports presented a problem for technicians who still needed to program these controllers.

By using the 1747-UIC, maintenance personnel can connect a modern laptop with a USB interface to a DH-485 network, enabling:

• Downloading or uploading ladder logic programs to SLC 500 controllers.

• Online editing and monitoring of controller programs.

• Troubleshooting network issues and node communications.

• Accessing PanelView terminals that communicate over DH-485.

This simple yet powerful device therefore extends the useful life of entire automation systems by ensuring that programming access remains available regardless of changes in PC hardware standards.

Key Features

Some of the main features of the 1747-UIC that make it so widely used include:

• USB Interface: Fully compatible with USB 1.1 and USB 2.0 ports, allowing connection to nearly any modern laptop or desktop PC.

• Automatic Protocol Conversion: Internally converts USB data packets to DH-485 frames, eliminating the need for user intervention or manual configuration.

• RS-485 Network Support: Provides isolated RS-485 network connections through both RJ45 and terminal block connectors.

• LED Indicators: Offers clear visual feedback on power, USB connection status, and network activity, assisting with troubleshooting.

• Software Compatibility: Works with RSLogix 500, RSLinx Classic, and other Rockwell Automation software tools that support DH-485.

• Portable and Rugged: Small and lightweight, easy to carry in a technician’s toolkit, and built to withstand the rigors of field use.

Technical Specifications

The following table outlines the key technical specifications of the Allen-Bradley 1747-UIC:

This table provides engineers and technicians with a quick reference to confirm compatibility with their systems and ensure that they have the right tool for their DH-485 communication needs.

Installation and Setup

Setting up the 1747-UIC is designed to be simple and quick:

1. Install Drivers: Before connecting to the DH-485 network, install the required drivers on the PC. Drivers are available from Rockwell Automation’s support website.

2. Connect to PC: Use the included USB cable to connect the UIC to the computer. The device will be powered by the USB port.

3. Connect to DH-485 Network: Choose either the RJ45 port or the terminal block connection to tie into the network. Ensure correct polarity and proper network termination.

4. Configure RSLinx: Open RSLinx Classic, create a new DF1 driver, and set the appropriate COM port assigned to the UIC by the operating system.

5. Verify Communication: Observe the LED indicators to confirm proper connection and test communication with the networked devices.

The process typically takes only a few minutes, and once configured, the settings can be reused, making future connections even faster.

Applications and Use Cases

The 1747-UIC is commonly used in:

• Legacy System Maintenance: Keeping older SLC 500 controllers and DH-485 PanelView terminals in service without requiring expensive hardware upgrades.

• System Troubleshooting: Field engineers can quickly connect to a network, diagnose node communication failures, and restore system functionality.

• Program Updates: When new features or process changes require updates to controller logic, the UIC provides a reliable interface to download new programs.

• Training and Simulation: Educational facilities teaching PLC programming often use the UIC to connect to real controllers for hands-on learning.

Benefits to End Users

Using the 1747-UIC delivers several practical advantages:

• Cost Savings: Avoids costly replacement of legacy controllers by allowing continued access for programming.

• Ease of Use: Plug-and-play USB connection and familiar Rockwell software make setup straightforward.

• Reliability: Robust design ensures consistent communication even in electrically noisy industrial environments.

• Flexibility: Supports both RJ45 and terminal block connections, making it versatile for various network layouts.

• Future-Proofing: Allows modern laptops without serial ports to continue servicing DH-485 equipment.

Maintenance and Lifecycle

Because the 1747-UIC has no moving parts and is powered through USB, maintenance is minimal. Users should periodically check the cable and connectors for physical wear and ensure that drivers remain up to date. Rockwell Automation occasionally releases driver updates to improve compatibility with new versions of Windows operating systems, so staying current helps avoid connection issues.

In terms of lifecycle planning, many organizations keep at least one spare UIC available in the maintenance department to avoid delays during troubleshooting or emergency repair situations.

Environmental and Safety Considerations

The 1747-UIC is designed for use in typical industrial control environments and complies with international safety and EMC standards. Its isolated design helps protect both the PC and networked devices from electrical faults. When not in use, the UIC should be stored in a protective case or compartment to avoid mechanical damage.

Conclusion

The Allen-Bradley 1747-UIC is a vital tool for anyone responsible for maintaining or upgrading DH-485-based automation systems. By bridging the gap between modern USB-equipped PCs and legacy networks, it ensures that programming access remains available long after traditional serial interfaces have disappeared from computers. Its rugged construction, simple installation, and reliable performance make it a favorite among field service technicians, system integrators, and controls engineers.

Whether you are extending the life of existing equipment, performing troubleshooting, or conducting training, the 1747-UIC is an essential piece of hardware that helps keep legacy automation systems connected and operational. It is not merely an adapter — it is a key enabler of continuity and productivity in industrial environments.