title: how to edit simulink plutosdr qpsk example
body: <p>I am working with this example from MathWorks: <a href="https://www.mathworks.com/help/supportpkg/plutoradio/examples/qpsk-transmitter-with-adalm-pluto-radio-1.html" rel="nofollow noreferrer">https://www.mathworks.com/help/supportpkg/plutoradio/examples/qpsk-transmitter-with-adalm-pluto-radio-1.html</a></p>
  
  <p>When i run the example it creates an <code>sdrqpsktx</code> variable in the matlab workspace</p>
  
  <p>I want to change <code>sdrqpsktx.MessageBits</code> to something smaller. </p>
  
  <p>When i run the following code in matlab:</p>
  
  <pre><code>a = sdrqpsktx.MessageBits(1:448);
  sdrqpsktx.MessageBits = a;
  </code></pre>
  
  <p>I successfully change <code>sdrqpsktx.MessageBits</code> to <code>a</code>. </p>
  
  <p>However when i run this in simulink <code>sdrqpsktx.MessageBits</code> changes back to its original size. </p>
  
  <p>How do i permanently change <code>sdrqpsktx.MessageBits</code> and run the example with my changes?</p>
  
  <p>Thank you.</p>