The OPC UA "Aggregating Server" pattern consists of exposing, through a single OPC UA server, data coming from multiple sources (Modbus PLCs, BACnet devices, SQL databases), so as to simplify integration on the SCADA/MES side.
True
An Aggregating Server is a single front-facing OPC UA server with backend connectors to heterogeneous sources: Modbus PLCs, BACnet devices, Siemens S7 controllers, SQL databases, REST APIs and so on. Each source is mapped into a hierarchical branch of the OPC UA Address Space, so a SCADA or MES client sees one unified semantic tree instead of several incompatible drivers. This pattern is the de-facto standard for modern data aggregation in Industrie 4.0 and is implemented by products such as Kepware KEPServerEX, Matrikon and the Unified Automation OPC UA Gateway.
Treat the aggregating server's Address Space as a contract for downstream clients: design it to be vendor-neutral so you can swap a Modbus PLC for an OPC UA-native PLC later without breaking a single SCADA tag binding.
OPC UA bank in preparation
The full OPC UA bank isn't available yet. Drop your email to get notified at launch and grab an early-bird discount.
Join the waitlist →See the 9 other OPC UA practice questions
Related questions
- OPC UA supports two communication patterns: Client/Server (the classic Request/Response model) and Pub/Sub (publish/subscribe over MQTT or UDP multicast/unicast), the latter introduced in version 1.04 to address Industrie 4.0 use cases.1. Architecture · Client/Server vs. Pub/Sub
- The OPC UA Address Space is a hierarchical structure of Nodes linked by typed References (HasComponent, HasProperty, HasTypeDefinition, etc.), exposed as a graph that clients can walk through the Browse service.1. Architecture · Address Space
- The main OPC UA Service Sets are: Discovery, SecureChannel, Session, NodeManagement, View, Query, Attribute (Read/Write), MonitoredItem, Subscription, and Method (Call).3. Services · Hauptsächliche Service Sets
- OPC UA separates Application authentication (the client/server X.509 certificate) from User authentication (the actual end-user login), which can be Anonymous, Username/Password, or User Certificate.4. Security · User-Authentifizierung
- PA-DIM (Process Automation Device Information Model) is an OPC UA Companion Specification for process transmitters (temperature, pressure, flow, level), standardising 70+ parameters that are read identically on Endress+Hauser, Yokogawa, Siemens and ABB devices.6. Companion Specs · PA-DIM