/**
* Check if the message CRC is ok
* @return void
*/
private function performChecksum()
{
$ct = AdsbUtils::getChecksumTable();
$this->_valid = false;
$checksum = intval(substr($this->_msg, 22, 6), 16);
$crc = 0;
for ($i = 0; $i < strlen($this->_bin); $i++) {
if ($this->_bin[$i]) {
$crc = $crc ^ intval($ct[$i], 0);
}
}
if ($crc == $checksum) {
$this->_valid = true;
}
}
