title: Simulink: Error evaluating expression
body: <p>When I try to simulate ADC in Simulink, I get the following error:</p>
  
  <p>"Error evaluating expression 'sim_time/(fs*10^6)' for 'StopTime' specified in the Configuration Parameters dialog for block diagram 'ADC': Undefined function or variable 'sim_time'."</p>
  
  <p>Where the 'sim_time' variable should be defined and how?</p>
  
  <p>I tried to google it, but what I found is not clear for me. Any help, please?</p>