<?xml version="1.0"?>
<block>
  <name>Controlled const source</name>
  <key>gsm_controlled_const_source_f</key>
  <category>GSM</category>
  <import>import gsm</import>
  <make>gsm.controlled_const_source_f($constant)</make>
  <callback>set_constant($constant)</callback>
  
  <param>
    <name>constant</name>
    <key>constant</key>
    <value>0</value>
    <type>float</type>
  </param>

  <sink>
    <name>constant_msg</name>
    <type>message</type>
    <optional>1</optional>
  </sink>

  <source>
    <name>out</name>
    <type>float</type>
  </source>
</block>