<form action="" method="post" >
<input type=text name=cmd />
<input type="submit" value="   send   " name=send />

<?php

  $filename = "/dev/ttyUSB1";



    if (!$handle = fopen($filename, 'r+'))

    {

      echo "The device isn't detected";

      exit;

    }

    else

    {

      if (fwrite($handle, $_POST['cmd']))

      {
        $data = fwrite($handle, $_POST['cmd']);
        var_dump( $data );

        echo "Command is sent";

      $reply = fread ($handle,4);
       echo $reply;



      }
        else

              echo "The device isn't read";

    }

               fclose($handle);
       exit;

?>