Unified Plant Connectivity: Secure OPC UA Aggregation Server

Department

Development department — PFE 2026–2027

Context

Industrial sites often run many OPC UA servers from different vendors, including PLCs, DCSs and devices. This forces end users to manage multiple connections, certificates and address spaces.

Project

Design and implement an OPC UA Aggregator Server that consolidates several underlying servers into a single, unified and secure address space, giving clients one access point to the whole plant.

Aggregator capabilities

• Unified address space with namespace remapping.
• Pass-through browse, read, write, methods and history.
• Shared subscriptions to reduce load on field servers.
• Central security using certificates, users and roles.
• Automatic reconnection and source-health status.

Main topics

• Study OPC UA specifications and aggregation patterns.
• Design the aggregation architecture and node mapping.
• Implement the server with the OPC UA .NET stack.
• Add security, buffering and reconnection handling.
• Validate interoperability, performance and compliance.

Deliverables

• Aggregator server source code and setup.
• Configuration interface for source servers.
• Documentation including user guide, report and test reports.

Expected results

A single secure access point to all OPC UA servers, fewer connections and less load on field devices, and simpler integration for SIOTH and third-party clients.

Keywords

OPC UA, Aggregation Server, Information Model, Cybersecurity, IIoT, .NET/C#, SIOTH.