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OPC UA PubSub to Cloud via MQTT Demo at Hannover Messe 2022


For the Hannover Messe Demo, the team at Prosys OPC wanted to show off our relevant expertise and try something new. We quickly came up with a plan to use our software in the Raspberry Pi 4 platform to present an OPC UA PubSub model that could be used for cloud connections using the MQTT protocol.

For this project, we acquired a Raspberry Pi 4 with the touchscreen addon. Using Prosys OPC UA SDK for Java, our team created a lightweight sample publisher that would serve as the basis for our demo. The demo is divided into two parts: a built-in event visualizer and the actual MQTT PubSub cloud connection.

Cloud Wall Demo

The event visualizer was configured into the demo to mimic a subscriber and show the JSON formatted data. Data contains sample values and simulated alarms and events generated by the publisher. This visualizer was also connected to a custom Web application that displayed the sample data using MQTT compatible JSON package form.

With the visualized PubSub connection ready, we configured an MQTT forwarder to publish the JSON sample data into the cloud. Using the MQTT protocol, we then connected the PubSub demo to the Hannover Messe cloud connectivity wall of OPC Foundation.

For the final wall demo, we configured all of this to run automatically on the Raspberry Pi upon startup. The process begins by starting the sample publisher and opening the chromium browser to autorun the visualizer application. Lastly, we connect the MQTT broker to the publisher to send the data to the cloud connectivity wall.

In addition to the PubSub MQTT cloud connection, we updated our OPC UA Simulation Server and OPC UA Browser compatible with the 64-bit Raspberry Pi OS for future solutions.

At Hannover Messe 2022, you can find us at Hall 8, Booth F07. If you’re interested in the demo or would like to ask some questions, meet us there or send an email to sales@prosysopc.com.


  • JSON = Java Script Object Notation
  • MQTT = Message Queuing Telemetry Transport
  • OPC UA = OPC Unified Architecture
  • PubSub = Publisher/Subscriber model
  • SDK = Software Development Kit

Tools used

  • Prosys OPC UA SDK for Java: Development kit for OPC UA
  • Mosquitto: Open-source MQTT broker
  • Spring: Open-source backend for the Web Application
  • Vaadin: Open-source frontend for the Web Application
Henri Toivola

Henri Toivola

Sales Engineer

Email: henri.toivola@prosysopc.com

Tags: OPC UA, PubSub, MQTT, Cloud, Demo

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About Prosys OPC Ltd

Prosys OPC is a leading provider of professional OPC software and services with over 20 years of experience in the field. OPC and OPC UA (Unified Architecture) are communications standards used especially by industrial and high-tech companies.

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