title: Why does ModBus require the RTS line?
body: <p>i cannot figure this out by myself. What is the point of the RTS (direction) line in the RS485 ModBus communication?</p>
  
  <p>There is no description about it on the internet, all the images in google only show the RX &amp; TX lines but i know that RTS is also used.</p>
  
  <p>Thanks</p>