if(CModule::IncludeModule("iblock")) {
    $arSelect = Array();
    $arFilter = Array(
        "IBLOCK_ID" => 52,
        "ACTIVE_DATE"=>"Y",
        "ACTIVE"=>"Y"
    );
    $res = CIBlockElement::GetList(Array(), $arFilter, false, Array(), $arSelect);
    while($ob = $res->GetNextElement()){
        $arFields = $ob->GetFields();
        $db_props = CIBlockElement::GetProperty(52, $arFields['ID'], "sort", "asc", array());
        while($ar_props = $db_props->Fetch()){
            $ar_props2[] = $ar_props;
        }
    }
    echo json_encode($ar_props2);
}