Basic usage example :

DB config

$DB['TEST'] = [
    'DB_HOST' => 'MSSQL\INSTANCE',
    'DB_USER' => 'username',
    'DB_PASS' => 'password',
    'DB_NAME' => 'DatabaseName',
];

include the class

include_once 'sqlsrv.php';

trying to connect to DB

try {
    $sql['TEST'] = new sqlsrv(
        $DB['TEST']['DB_HOST'],
        $DB['TEST']['DB_USER'],
        $DB['TEST']['DB_PASS'],
        $DB['TEST']['DB_NAME']
    );
} catch (Exception $e) {
    print_r($e->getMessage());
    die();
}

Simple Query

try {
    $query = $sql['TEST']->query(
        "SELECT * FROM Table WHERE Arg1 = ? AND Arg2 = ?",
        array($arg1, 'arg2')
    );
} catch (Exception $e) {
    print_r($e->getMessage());
}