Allen‑Bradley 1747‑UIC: USB‑to‑DH‑485 Interface Converter

April 9, 2026

The 1747‑UIC is a discontinued USB‑to‑DH‑485 converter that links USB‑enabled PCs to Allen‑Bradley SLC 500, MicroLogix, and PanelView DH‑485 networks, enabling programming, diagnostics, and data exchange without external power.

Allen‑Bradley 1747‑UIC: USB‑to‑DH‑485 Interface Converter - Featured image

The 1747‑UIC simplifies connecting modern USB computers to legacy Allen‑Bradley automation systems with DH‑485 ports, eliminating the need for outdated serial adapters or dedicated drivers in RSLinx. It streamlines programming, firmware updates, and real‑time monitoring for SLC 5/01–5/05, MicroLogix DH‑485 models, and PanelView terminals, reducing downtime during maintenance or system expansions. As a Rockwell Automation discontinued device (EOL: September 30, 2024), it remains a viable drop‑in solution for existing installations while requiring careful replacement planning for new projectsRockwell Automation.

Technical Insights

Multi‑Port Connectivity

USB 1.1 Port: 12 Mbps transfer rate, bus‑powered (<100 mA), with a 12‑inch integrated cable for tight cabinet spaces.
Two Switchable DH‑485 Ports: RJ‑45 and 8‑pin/9‑pin connectors, supporting DF1 (full/half‑duplex) and DH‑485 protocols for direct SLC 500/PanelView linking.
RS‑232 DB9 Port: Connects to SLC 5/03–5/05 Channel 0, MicroLogix, and CompactLogix RS‑232 interfaces.
500V DC Isolation: Protects PC and PLC circuits from industrial noise and ground loops.

Communication & Status Indicators

Baud rate range: 300–115.2 kbps (configurable) for flexible data transfer speeds.
Three green LEDs: OK (USB power/operation), USB (data activity), DH‑485 (network traffic) for quick diagnostics.
Embedded DH‑485 protocol support eliminates need for RSLinx DH‑485 drivers, simplifying setup.

Environmental & Physical Specs

Operating temperature: 0–60 °C (32–140 °F) for harsh factory environments.
Weight: ~0.28 kg; compact design for DIN rail or panel mounting.
Compliance: Meets BS EN 61340‑5‑1:2007 and ANSI/ESD S20.20:2014 for electrostatic discharge protection.

Installation & Maintenance

Setup Best Practices

Connect the 12‑inch USB cable to a PC’s USB 2.0 port (backward compatible with USB 1.1).
Select DH‑485 or RS‑232 port based on target device: Use RJ‑45 for SLC 5/01–5/03; DB9 for SLC 5/03–5/05 or MicroLogix.
Configure baud rate, parity, and stop bits in RSLinx to match the PLC/HMI (e.g., 19.2 kbps, 8N1).
Verify LED status: OK solid, USB flashing during data transfer, DH‑485 flashing for network activity.

Troubleshooting & Care

No Power: Ensure USB port is functional; avoid low‑power USB hubs.
No Communication: Check port selection (DH‑485/RS‑232), baud rate matching, and cable integrity.
Noise Interference: Use shielded DH‑485/RS‑232 cables and separate signal/power wiring to reduce EMI.
Routine Checks: Inspect connectors quarterly for corrosion; back up PLC programs to PC semi‑annually.

Buyer’s Guide FAQ

Is the 1747‑UIC still available?

No, Rockwell Automation discontinued it on September 30, 2024, with no planned replacement. Stock is limited to existing inventory; plan for migration to modern protocols (e.g., Ethernet/IP) for new systemsRockwell Automation.

What replaces the 1747‑UIC for new installations?

For new projects, use 1756‑ENBT (Ethernet/IP module for ControlLogix) or 1769‑ENBT (CompactLogix) for native USB/Ethernet connectivity. For legacy systems, third‑party USB‑to‑DH‑485 converters with 500V isolation are compatible but lack Rockwell’s native driver support.

Can the 1747‑UIC integrate with modern Rockwell systems?

It works with SLC 500, MicroLogix DH‑485 models, and PanelView terminals. For ControlLogix/CompactLogix, use Ethernet/IP modules instead, as DH‑485 is outdated for high‑speed, deterministic communication.

What precautions are needed for legacy system upgrades?

Document existing DH‑485 network topology and device addresses before replacement.
Test third‑party converters in a lab environment to ensure protocol compatibility.
Migrate critical programs to Ethernet/IP for improved security and performance in long‑term upgrades.

Final Notes

The 1747‑UIC remains a reliable solution for maintaining existing SLC 500 and MicroLogix systems, but new installations should prioritize Ethernet/IP for scalability and security. When replacing, assess your network’s communication needs and choose a modern adapter that aligns with current industrial automation standards.