Allen Bradley 1784-U2DHP USB to Data Highway Plus Adapter

Industrial Communication Applications and Legacy PLC Network Access Solutions

The Allen Bradley 1784-U2DHP USB to Data Highway Plus Adapter Cable is a specialized industrial communication interface designed to connect modern computers with Allen Bradley Data Highway Plus (DH+) networks. It provides engineers and maintenance technicians with a convenient method to access, monitor, program, and troubleshoot legacy PLC systems through a standard USB connection.

Designed as a replacement solution for older PCMCIA-based communication interfaces, the 1784-U2DHP allows laptops and industrial computers without traditional communication slots to communicate with DH+ networks. It is widely used in PLC maintenance, factory automation upgrades, system diagnostics, and legacy control system management.

The adapter cable supports Allen Bradley PLC-5 and compatible DH+ communication environments, making it a valuable tool for engineers maintaining existing automation installations. With its compact design, USB-powered operation, and dedicated DH+ communication capability, the 1784-U2DHP helps extend the service life of proven industrial control systems. 

Communication Performance Advantages and Engineering Benefits

Direct USB to DH+ Network Communication
The 1784-U2DHP provides a direct communication bridge between a computer USB port and Allen Bradley Data Highway Plus networks. This allows technicians to connect modern computers with existing PLC systems without requiring legacy communication hardware.

Ideal Solution for Legacy PLC Maintenance
Many industrial facilities continue operating reliable PLC-5 and DH+ based control systems. The adapter provides an efficient maintenance solution for programming, diagnostics, and troubleshooting tasks without replacing the entire control architecture.

Multiple DH+ Communication Rates
The adapter supports DH+ communication speeds of 57.6 Kbps, 115.2 Kbps, and 230.4 Kbps, allowing compatibility with different existing network configurations.

USB Powered Operation
The 1784-U2DHP receives power directly from the USB connection, eliminating the need for an external power supply and simplifying installation in field service environments.

Improved Field Service Efficiency
Technicians can use portable computers to access PLC systems directly on-site, reducing troubleshooting time and improving maintenance response efficiency.

Reliable Industrial Communication Design
The adapter features industrial communication protection and status indicators, helping users quickly identify connection conditions during commissioning and fault diagnosis.

Easy Integration with Rockwell Automation Software
The 1784-U2DHP is designed for use with Allen Bradley programming and communication environments, providing a practical connection method for industrial automation engineers.

Technical FAQs About Allen Bradley 1784-U2DHP USB to Data Highway Plus Adapter Cable

Q1: What is the main function of the Allen Bradley 1784-U2DHP?
A: The 1784-U2DHP is a USB-to-Data Highway Plus communication adapter used to connect computers with Allen Bradley DH+ networks.

Q2: Which communication protocol does the 1784-U2DHP support?
A: The adapter supports Allen Bradley Data Highway Plus (DH+) communication networks.

Q3: What DH+ communication speeds are supported by the adapter?
A: The 1784-U2DHP supports 57.6 Kbps, 115.2 Kbps, and 230.4 Kbps communication rates.

Q4: Can the 1784-U2DHP replace older communication cards?
A: Yes. It replaces older PCMCIA-based communication solutions such as the 1784-PCMK for computers without PCMCIA slots.

Q5: Which PLC systems can be accessed using the 1784-U2DHP?
A: It is commonly used with Allen Bradley PLC-5 systems and compatible DH+ network devices.

Q6: What should be checked if the adapter cannot communicate with a PLC?
A: Engineers should verify DH+ node addressing, communication rate settings, cable connections, driver installation, and PLC network status.

Q7: What causes unstable DH+ communication?
A: Common causes include incorrect baud rate settings, network termination problems, damaged communication wiring, or incorrect node configuration.

Q8: Does the 1784-U2DHP require an external power supply?
A: No. The adapter is powered through the USB connection from the connected computer.

Q9: What software environment is commonly used with this adapter?
A: The adapter is typically used with Allen Bradley communication software environments such as RSLinx for PLC connectivity and diagnostics.

Q10: What maintenance practices are recommended for the 1784-U2DHP?
A: Regular inspection of connectors, cable condition, driver configuration, and communication settings helps maintain reliable operation.