Dublerr

$url = "https://site.ru/source_file.xml";
if ($response = file_get_contents($url) and !empty($response) and $xml = new SimpleXMLElement($response)) {
    echo $xml->dlina_puple . " / " .  (int)$xml->dlina_puple[0]->attributes()->col_popytok . "<br />";
    echo $xml->vysota_puple . " / " .  (int)$xml->vysota_puple[0]->attributes()->col_popytok . "<br />";
} else {
    echo 'Ошибка открытия файла XML';
}