$ob = Win32::SerialPort->new($PORT) ;
$ob->baudrate(19200);
$ob->databits(8);
$ob->stopbits(1);
$ob->buffers(4096, 4096);

$ob->parity("none");
$ob->write_settings;
$ob->save($CONF);
##</code><code>##

$send="0xa10xa2";          # "0xa10xa2"
$send="\x{a1}\x{a2}";      # "กข"
$send=hex("a1a2");         # 41378              
$send=hex("a1").hex("a2"); # 161162

$ob->write($send);
##</code><code>##

# read from array
foreach $array(@array){                

	$ob->parity($parity1);        # change parity
	$ob->write_settings;
          $ob->save($CONF);

	$send=$char1.$char2.$char3.$char4.;        # sending hexadecimal characters
         $ob->write($send);

	# receiving from COM port
	$gotit = $ob->streamline;    
         die "got undef from streamline! $!" if (!defined ($gotit)); 
         return if ($gotit eq "");

	if($gotit eq $char5){                                            # is $char5 received?

		$ob->parity($parity2);                                # change parity
		$ob->write_settings;
                  $ob->save($CONF);

		$ob->write($array);                                    # send from array
	}
}