How to connect code igniter 3.1.8 with sql server 2000

问题

I'm trying to connect Code Igniter 3.1.8 with sql server 2000 but was not possible, i'm use php 5.6, Does someone know to make it works? this is my config database

$db['default'] = array(
'dsn'   => '',
'hostname' => '200.200.200.242\SERVERBARU',
'port' => '1433',
'username' => 'sa',
'password' => 'm45t3r',
'database' => 'DEPO2017',
'dbdriver' => 'sqlsrv',
'dbprefix' => '',
'pconnect' => FALSE,
'db_debug' => (ENVIRONMENT !== 'production'),
'cache_on' => FALSE,
'cachedir' => '',
'char_set' => 'utf8',
'dbcollat' => 'utf8_general_ci',
'swap_pre' => '',
'encrypt' => FALSE,
'compress' => FALSE,
'stricton' => FALSE,
'failover' => array(),
'save_queries' => TRUE);

and this is my controller for call dummy data from table

public function index()
{
     $this->db = $this->load->database('default', TRUE);
    $this->load->view('welcome_message');
    echo "string";

    $query = $this->db->query("select TOP 10 * from dbo.Dokter");
    echo $query;

}

and i was enabling in php.ini