title: My simple Stateflow model shows error
body: <p>I'm almost new to Simulink and Stateflow. I am trying to model some simple state machines. But when trying to run the model, it shows errors (on the main Matlab screen). </p>
  
  <pre><code>Warning: Input port 1 of 'sample/If' is not connected. 
  Warning: Output port 1 of 'sample/If' is not connected. 
  Parsing failed for machine: "sample"(#90)
  </code></pre>
  
  <p>1) Is there anything wrong with this? </p>
  
  <p>2) One more question: How can I add a timer on S2? e.g. we can not stay more than 2 minutes on S2. So as soon as we enter S2, a timer starts, and when it reaches 2 minutes, then should transition to S3.</p>
  
  <p>P.S. For some reasons, the stateflow thumbnail on simulink scheme is not showing the updated model; there is no <code>condition</code> and <code>if_outfput</code> variables anymore!
  <img src="https://i.stack.imgur.com/Sf4eq.png" alt="enter image description here">
  <img src="https://i.stack.imgur.com/KhTwa.png" alt="enter image description here"></p>