Pyry Grönholm

OPC UA vs. MQTT – Getting data out of 100+ machines

The plant is part of an international manufacturing group, with machines from many vendors and generations. The trigger was an MES project due in about two years. Prosys first replaced the outdated OEE system and built status dashboards. Machines were connected wherever possible: via OPC UA servers, Siemens, Beckhoff and EtherNet/IP connectors, Modbus through existing gateways, or an additional PLC next to the old one. The team initially expected 30 to 50% of the machines – according to Pyry, it was significantly more. The data is harmonized in open OPC UA information models for status, OEE and MES, identical across all machines. The customer owns the model, not the software vendor. A newly connected machine is live in under an hour. Then the question many in the community ask: OPC UA or MQTT – which wins for industrial data? Pyry has a clear answer, explains it with an everyday analogy and links it to a project detail: The original plan is not what was implemented in the end. Key takeaways One information model per machine type is enough; after that, each new machine is just a template plus mapping. Gateways a legacy system already wired to unconnected PLCs can still be used via Modbus. If automation engineers model each variable's unit, value range and meaning, data engineers and AI understand the data. In large corporations, find out early how IT provisioning and permissions work – or lose a lot of time waiting.