01TCP vs RTU
Modbus TCP runs over Ethernet and is simplest where the network exists. Modbus RTU runs over RS-485 serial and is everywhere in older plants. An industrial Pi with an isolated RS-485 port handles both, so it bridges legacy serial gear to a TCP/MQTT world.
02Using it well
Poll at a sane rate, handle timeouts and CRC errors gracefully, and map registers explicitly. A Pi makes a reliable Modbus gateway when the polling loop is written defensively — which is exactly the kind of plumbing we standardize on our gateway builds.
Common questions
The ones we're asked on every first call.
Yes — that's one of the most common Pi deployments: read brownfield equipment over Modbus RTU/TCP and republish to MQTT or OPC-UA for dashboards and the cloud, without touching the control loop.
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