sub proces_no_more_than_50 {

  my($port,@addresses)=@_;
  if ($#addresses >= 50) {
     &execute( $port, map {shift @addresses} 1..50 );

  }
  else{ &execute($port, @addresses); undef @addresses;}

  &proces_no_more_than_50($port,@addresses) if defined $addresses[0];
}