M-Bus

SPX Server ships two M-Bus components:

• mbus — M-Bus master/client (serial / TCP / loopback transports)

• mbus_server — in-memory loopback server used for tests and tooling

mbus (client)

YAML key: mbus

Minimal example:

attributes:
  flow_temp: 35.0

communication:
  - mbus:
      transport: tcp
      host: 127.0.0.1
      port: 10001
      poll_interval: 5.0
      bindings:
        - name: heat_meter
          primary_address: 5
          frames:
            - name: flow_temperature
              codec: float32
              direction: inbound
              attribute: "#attr(flow_temp)"
              poll_interval: 2.0

Notes:

• Serial transport requires an M-Bus library (see server code for the dependency guard).

• loopback transport is available for tests (attach an mbus_server).

mbus_server (loopback server)

YAML key: mbus_server

attributes:
  energy_kwh: 12.5

communication:
  - mbus_server:
      bindings:
        - name: water_meter
          primary_address: 1
          frames:
            - name: energy_total
              record_key: energy_total
              codec: float32
              direction: outbound
              attribute: "#attr(energy_kwh)"