SCADA system modernization: OPC UA, MQTT and Sparkplug

In recent years SCADA has been moving from a supervisory screen toward a platform that gathers data, connects systems and feeds analysis. Behind the trend are open standards that reduce vendor-specific integration work.

OPC UA suits cases that need a structured information model inside a site: names, data types, relationships between components and built-in security. MQTT with Sparkplug B suits light reporting from many remote sites: a lightweight publish-and-subscribe model, birth and death messages that show connection state, and a uniform topic structure. They complement each other rather than compete.

Processing at the edge saves traffic and cost. Instead of sending every sample to the cloud, an edge gateway filters, aggregates and holds data during an outage (store-and-forward), and sends only what is needed. At sites with weak cellular coverage this is the difference between a gap in the data and a complete record.

How to start: map the existing sources (Modbus, controllers, remote units); pick one pilot site; define a consistent naming model before connecting more sites; and add security, encryption and authentication, already in the pilot. There is no need to replace the whole system, and most successes start with one gateway and one site.

For a phased upgrade plan for your SCADA system, contact the Teleris engineering team. The information is general and based on industry trends; verify it against the requirements and products of your project.