# KNX Input Plugin

This service plugin listens for messages on the [KNX home-automation bus][knx]
by connecting via a KNX-IP interface. Information about supported KNX
datapoint-types can be found at the underlying [`knx-go` project][knxgo].

⭐ Telegraf v1.19.0
🏷️ iot
💻 all

[knx]: https://www.knx.org
[knxgo]: https://github.com/vapourismo/knx-go

## Service Input <!-- @/docs/includes/service_input.md -->

This plugin is a service input. Normal plugins gather metrics determined by the
interval setting. Service plugins start a service to listen and wait for
metrics or events to occur. Service plugins have two key differences from
normal plugins:

1. The global or plugin specific `interval` setting may not apply
2. The CLI options of `--test`, `--test-wait`, and `--once` may not produce
   output for this plugin

## Global configuration options <!-- @/docs/includes/plugin_config.md -->

Plugins support additional global and plugin configuration settings for tasks
such as modifying metrics, tags, and fields, creating aliases, and configuring
plugin ordering. See [CONFIGURATION.md][CONFIGURATION.md] for more details.

[CONFIGURATION.md]: ../../../docs/CONFIGURATION.md#plugins

## Configuration

```toml @sample.conf
# Listener capable of handling KNX bus messages provided through a KNX-IP Interface.
[[inputs.knx_listener]]
  ## Type of KNX-IP interface.
  ## Can be either "tunnel_udp", "tunnel_tcp", "tunnel" (alias for tunnel_udp) or "router".
  # service_type = "tunnel"

  ## Address of the KNX-IP interface.
  service_address = "localhost:3671"

  ## Measurement definition(s)
  # [[inputs.knx_listener.measurement]]
  #   ## Name of the measurement
  #   name = "temperature"
  #   ## Datapoint-Type (DPT) of the KNX messages
  #   dpt = "9.001"
  #   ## Use the string representation instead of the numerical value for the
  #   ## datapoint-type and the addresses below
  #   # as_string = false
  #   ## List of Group-Addresses (GAs) assigned to the measurement
  #   addresses = ["5/5/1"]

  # [[inputs.knx_listener.measurement]]
  #   name = "illumination"
  #   dpt = "9.004"
  #   addresses = ["5/5/3"]
```

### Related tools

- [knx-telegraf-config-generator][knx_config_generator]:  generates a Telegraf
 configuration from a KNX project file

[knx_config_generator]: https://github.com/svsool/knx-telegraf-config-generator

### Measurement configurations

Each measurement contains only one datapoint-type (DPT) and assigns a list of
addresses to this measurement. You can, for example group all temperature sensor
messages within a "temperature" measurement. However, you are free to split
messages of one datapoint-type to multiple measurements.

> [!IMPORTANT]
> You should not assign a group-address (GA) to multiple measurements!

## Metrics

Received KNX data is stored in the named measurement as configured above using
the "value" field. Additional to the value, there are the following tags added
to the datapoint:

- `groupaddress`: KNX group-address corresponding to the value
- `unit`:         unit of the value
- `source`:       KNX physical address sending the value

To find out about the datatype of the datapoint please check your KNX project,
the KNX-specification or the "knx-go" project for the corresponding DPT.

## Example Output

This section shows example output in Line Protocol format.

```text
illumination,groupaddress=5/5/4,host=Hugin,source=1.1.12,unit=lux value=17.889999389648438 1582132674999013274
temperature,groupaddress=5/5/1,host=Hugin,source=1.1.8,unit=°C value=17.799999237060547 1582132663427587361
windowopen,groupaddress=1/0/1,host=Hugin,source=1.1.3 value=true 1582132630425581320
```
