$output = `mode COM1: BAUD=115200 PARITY=N data=8 stop=1 XON=off TO=on`;

echo "$output";

$fp = fopen('COM1', 'r+');

if (!$fp)
{
      echo "Port not accessible";
}
else
{
     echo "Port COM1 opened successfully";
}

$writtenBytes = fputs($fp, "Hello");

echo"Bytes written to port: $writtenBytes";

$buffer = fgets($fp);

echo "Read from buffer: $buffer";