Your SCADA system tells you when a line stops. What it usually can’t tell you is whether the switch or the server underneath went down first. That blind spot was the topic of a live episode on the 4.0 Solutions channel on November 5, 2026. Host Walker Reynolds asked Eric Eckman, OT Channel Manager, US at Paessler, and David Montoya, Head of Operational Technology at Paessler, why it’s so hard to monitor the infrastructure we use to monitor our processes.
Watch the full recording below, or read on for four takeaways for anyone responsible for OT network monitoring.
In IT, monitoring infrastructure is standard practice. In OT, Walker estimates it happens maybe 1 to 5% of the time. Most plants just assume the network will work.
Eric heard the same thing for years when he sold fault-tolerant computers for control rooms: downtime came from switches or servers far more often than expected. Controls engineers watch PLCs and HMIs, IT watches the business network. The industrial switches and firewalls on the plant floor sit in between, and often nobody owns them.
David told a story from a proof of concept at a large car manufacturer. Nine plants went down, and engineers spent almost 12 hours checking PLCs and the automation stack. The cause was a server at level 3 of the Purdue model that sent production orders to the plants. An application update on it had failed.
Nobody looked there because the server sat in the no man’s land between IT and OT. One alarm in the SCADA would have pointed people to the right place right away. And at Walker’s average of $120,000 per hour of downtime, those 12 hours weren’t cheap.
Twelve hours of troubleshooting because nobody watched one server? See how PRTG keeps an eye on the infrastructure under your SCADA in our short demo video.
Monitoring data helps a lot more when it doesn’t stay locked inside one dashboard. PRTG has sensors for OPC UA, MQTT and Modbus, and with the PRTG OPC UA Server extension, monitoring data from your OT network goes straight into your supervisory and control systems.
That’s good news if you’re building a Unified Namespace. Want machine learning to find connections between switch health and bad production outcomes? Then both kinds of data have to live in the same place. Our white paper on monitoring industrial IT and OT together shows how the right teams get the right data from across both worlds.
David’s advice for a first test is down to earth: check the temperature of the switches that connect your production cells. Dusty fans make temperatures rise, the switch starts to malfunction, and sooner or later your PLCs drop off the network.
If a full discovery feels too invasive for OT, run it only on the IP addresses of your servers and switches. First scans often turn up low disk space or TLS certificates that expired 300 days ago. Walker tried it on his own development board and found a Raspberry Pi driver polling his PLC so often that messages got dropped. Is your OT network air-gapped? Our white paper on deploying PRTG in air-gapped and OT environments explains where to place the core server and probes and how to install PRTG without internet access.
The episode covers a lot more in about 80 minutes, from air-gapped networks to the question of whether you should just build your own monitoring with AI. Worth watching if you work anywhere near the IT/OT boundary.