title: Syntax for Getting Ouput Variable in Structured Text
body: <p>I'm trying to use a library defined function (CCaux for Cross Control Products) with the following interface:</p>
  
  <pre><code>FUNCTION Lightsensor_GetIlluminance : eErr (* return error status. 0 ERR_SUCCESS, otherwise error code.*)
  VAR_OUTPUT
      value: UINT;(*Illuminace value (Lux)*)
  END_VAR
  </code></pre>
  
  <p>I can't seem to find the correct syntax for getting the "value" from the output variable. Here is what I have in my program:</p>
  
  <pre><code>VAR
      illumen : UINT;
  END_VAR
  </code></pre>
  
  <p>Where I want <code>illumen</code> to be set to the output variable of <code>Lightsensor_GetIlluminace</code>. The following doesn't work since it sets the variable to the <code>eErr</code>:</p>
  
  <pre><code>illumen := CCAux.Lightsensor_GetIlluminance();
  </code></pre>
  
  <p>And:</p>
  
  <pre><code>illumen := CCAux.Lightsensor_GetIlluminance.value;
  </code></pre>
  
  <p>Doesn't work because I get the error <code>'value' is no input of 'Lightsensor_GetIlluminance'</code></p>
  
  <p>And:</p>
  
  <pre><code>illumen := CCAux.Lightsensor_GetIlluminance(value := illumen);
  </code></pre>
  
  <p>fails because <code>Lightsensor_GetIlluminance take exactly '0' inputs</code></p>
  
  <p>I am using CoDeSys for context.</p>