outputprotocol.xml

<?xml version="1.0"?>

<PropertyList>
 <generic>
  <output>
   <line_separator>newline</line_separator>
   <var_separator>,</var_separator>

   <!-- Get control values -->
   <chunk>
    <name>aileron</name>
    <type>float</type>
    <node>/controls/flight/aileron</node>
    <format>%f</format>
   </chunk>
   
   <chunk>
    <name>elevator</name>
    <type>float</type>
    <node>/controls/flight/elevator</node>
    <format>%f</format>
   </chunk>
   
   <chunk>
    <name>throttle</name>
    <type>float</type>
    <node>/controls/engines/engine/throttle</node>
    <format>%f</format>
   </chunk>
   
   <!-- Get aircraft speed -->
   <chunk>
     <name>airspeed-kt</name>
     <type>float</type>
     <format>%f</format>
     <node>/velocities/airspeed-kt</node>
   </chunk>
   
 </output>
 </generic>
</PropertyList>