Architecture

The bridge sits between Modbus TCP devices and MQTT consumers.

Data flow

1. The bridge polls Modbus points from one or more sources.
2. Values are decoded and published to MQTT state topics.
3. Write commands are received on matching /set topics.
4. The bridge encodes and writes values back to Modbus.

Design goals

• isolate each Modbus source in its own poll loop
• keep topic structure stable and predictable
• recover gracefully from transient broker/device failures