M-Bus

The mbus adapter is a wired Meter-Bus master per EN 13757-2/-3. It initializes meters and decodes their variable-data responses into clean {name, value, unit} readings.

How it works

Configure a list of meters by primary address. For each, the adapter sends SND_NKE then REQ_UD2, and decodes the long-frame response (long header + variable data set).

The built-in DIF/VIF decoder covers the common units:

• Energy (Wh, J), volume (m³), mass (kg)
• Power (W), volume flow (m³/h), mass flow (kg/h)
• Flow / return / external temperatures
• Pressure (bar), on-time
• BCD / integer / float data encodings

:::note Wireless wM-Bus is out of scope This adapter is for wired M-Bus. Wireless wM-Bus needs a separate dongle and is not handled here. :::

REST actions

Action	Body	Effect
read	—	Read all configured meters now.
init	—	Send SND_NKE initialization.
scan	{start, end}	Scan a range of primary addresses for meters.
status	—	Report adapter / meter status.

Outputs

Output	Behavior
MQTT	Publishes {name, value, unit} readings under the port prefix.
REST	The actions above.
Webhooks	Fan out readings.