digraph H {

  parent [
   shape=plaintext
   label=<
     <table border='1' cellborder='1'>
       <tr>
            <td bgcolor="grey" port='chan_1'>Channel 1</td>
            <td bgcolor="grey" port='chan_2'>Channel 2</td>
            <td bgcolor="black" port='chan_3'><font color="grey">Channel 3</font></td>
         </tr>
     </table>
  >];


}