AB PLC-5 on DH+ to Ethernet Migration

Connecting legacy PLC-5 to Ethernet networks is a top priority for manufacturing facilities seeking real-time data visibility. Developed under Rockwell Automation, Allen-Bradley PLC-5 controllers remain dependable workhorses, but modernizing Data Highway Plus (DH+) channels into modern industrial Ethernet is essential for SCADA and MES integration.

A full controller “rip-and-replace” upgrade often requires extensive rewiring, prolonged downtime, retraining technicians, and massive capital expenditures. Bridging your existing hardware via dedicated gateways protects legacy investments while achieving modern network performance.

Key Reasons Plants Maintain PLC-5 Controllers

• Proven Durability & Uptime: Decades of stable, continuous operation in harsh industrial environments with near-zero hardware failure rates.
• Avoid High Replacement Costs: Eliminates complex chassis migration, complete panel rewiring, and extended plant shutdowns.
• Verified Logic & Compliance: Keeps validated RSLogix 5 ladder logic running in regulated sectors (pharmaceutical, aerospace, oil & gas) without re-validation risks.
• Field Wiring Integrity: Preserves extensive 1771 I/O wiring, sensors, and actuators already in place.

Which PLC-5 Processors Use DH+?

Every PLC-5 processor family includes DH+ communication, so the ANC-120e and ANC-100e can reach any of them:

Not sure which model you have? The catalog number on the processor (1785-L…) identifies it. Contact us and an engineer will confirm compatibility before you order.

Hardware Solutions for PLC-5 to Ethernet Bridging

Modern industrial networking provides two direct, plug-and-play gateway solutions to connect legacy DH+ hardware to modern Ethernet and USB networks:

1. Permanent PLC-5 to Ethernet Gateway: ANC-100e Converter

The ANC-100e is a pocket-sized, DIN-rail mountable gateway that converts Ethernet/IP directly to Data Highway Plus (DH+). It acts as a direct, cost-effective replacement for obsolete 1756-DHRIO modules or discontinued 1784-PKTX cards, featuring browser-based setup and automatic baud rate detection.

2. Maintenance & Programming Cable: ANC-120e USB Interface

For plant maintenance teams needing to program and troubleshoot PLC-5 or SLC 5/04 processors directly from Windows 10/11 laptops via RSLogix 5 and RSLinx Classic, the ANC-120e USB-to-DH+ cable provides an economical, plug-and-play alternative to the OEM 1784-U2DHP.