ProSoft AN-X2-AB-DHRIO | Allen-Bradley to Modbus RTU Gateway | New Project Integration Guide

Key Technical Specifications

• Product Model: AN-X2-AB-DHRIO
• Manufacturer: ProSoft Technology (a Rockwell Automation Encompass Partner)
• Target Systems: Allen-Bradley SLC 500, PLC-5, MicroLogix via DH+ or DH485; Modbus RTU field devices (RTUs, meters, drives)
• Communication Ports:
  • Port 1: RS-485/422 for DH+ or DH485 (isolated, up to 500 kbps)
  • Port 2: RS-485 for Modbus RTU (isolated, up to 115.2 kbps)
• Configuration Method: Web-based UI and Studio 5000 Add-On Instructions (AOI)
• Power Supply: 10–30 VDC, 2 W typical
• Mounting: DIN rail (35 mm)
• Operating Temperature: 0°C to 60°C
• Certifications: UL, CE, FCC Class A

PROSOFT AN-X2-AB-DHRIO

Core Performance and Selection Advantages

The AN-X2-AB-DHRIO delivers significant value in projects where legacy Allen-Bradley controllers must coexist with modern Modbus-enabled field devices. Unlike generic protocol converters, it is purpose-built for Rockwell ecosystems, offering deep integration through native Studio 5000 AOIs—eliminating custom ladder logic for data mapping. This reduces engineering time by up to 40% compared to third-party gateways. Its dual isolated serial ports prevent ground loops and electrical noise from disrupting sensitive PLC communications, a common issue in industrial environments with long cable runs. The module supports concurrent read/write operations with sub-10 ms update cycles, ensuring real-time responsiveness for control applications. From a total cost of ownership (TCO) perspective, it avoids the need for additional communication processors or intermediate PLCs, simplifying architecture and reducing panel space, wiring, and long-term maintenance overhead.

PROSOFT AN-X2-AB-DHRIO

System Integration and Expandability

Integration begins in Rockwell’s Studio 5000 environment, where the included AOI allows engineers to configure data exchange using familiar tag-based structures—no external configuration tools required. This streamlines commissioning and enhances version control. On the network side, while the AN-X2-AB-DHRIO itself operates over serial links, it enables indirect connectivity to higher-level systems: Modbus RTU data can be aggregated into the Allen-Bradley controller and then published via EtherNet/IP to SCADA (using CIP protocols) or to cloud platforms via OPC UA servers connected to the same control network. For larger deployments, multiple AN-X2 units can be deployed in parallel across different DH+ channels without central bottlenecks. The device supports up to 100 Modbus registers per transaction and configurable retry mechanisms for robust operation in noisy environments. Although it does not support built-in redundancy, its low cost and fast recovery (<2 seconds after power cycle) make it suitable for non-safety-critical applications where high availability is achieved through system-level design rather than component redundancy.