This is the documentation for the current development branch of the CometVisu. It is possible that some of the described features are not yet available in the current release.

Also there might be lots of errors in this documentation as some parts of the content have been translated by an online translation service.

The Speech plugin

Available since version: 0.10.0
Author: Tobias Bräutigam


Use the Web Speech API ( to make text-to-speech service available. This plugin listens to a address and forwards the incoming data to the browser TTS engine (if the browser supports it)

Simple example
<speech lang="en">
 <address transform="OH:string" mode="read">Speak</address>
Example preventing repetition within a timeout and use mapping
   <plugin name="speech" />
   <mapping name="speak">
     <entry value="0">Hello, welcome home</entry>
     <entry value="1">Please close all windows</entry>
     <entry value="2">Please close all doors</entry>
<speech lang="en" repeat-timout="300" mapping="speak">
 <address transform="DPT:5.010" mode="read">Speak</address>


For a general understanding of how the configuration files are structured and what elements and attributes are it is recommended to read this section first: visu-config-details.

The behaviour and appearance of the speech plugins can be influenced by using certain attributes and elements. The following tables show the allowed attributes and elements and their possible values. The screenshots show, how both can be edited in the editor.

Attributes underlined by ..... are mandatory, all the others are optional and be omitted.

Allowed attributes in the speech-element

Element Attribute
  Name Content Description
speech lang de, en, es, fr, it or ru The language that should be used to speak the text.
mapping string Map the bus value to a message for text-to-speech output. You can e.g. map numbers to messages.
repeat-timeout number > 0 Do not repeat saying the same content within the given timeout (in seconds). 0 means: never repeat the same content.

Allowed child-elements und their attributes

Element Attribute
Structure Name Content Description
  • address
transform string  
mode disable, read, write or readwrite  
variant string  
format-pos decimal  
  • address
  • #text
  string The GA (like: 12/0/7) for KNX-backends or the item name for openHAB-backend


It is possible to manually edit the visu_config.xml and add an entry for the speech plugin.


Make sure that you only use UTF-8 encoded characters by settings the encoding in your XML-editor to UTF-8 mode!


[1]The simple view might not show everything. To see all elements/attributes use the expert view.