xcrud error

//...file xcrud_config.php...

    public static $dbname = 'db_kedua'; // Your database name
    public static $dbuser = 'root'; // Your database username
    public static $dbpass = '1234'; // // Your database password
    public static $dbhost = 'localhost'; // Your database host, 'localhost' is default.



//...file controllernya...
function jurnal()
{
    $xcrud = xcrud_get_instance();
    $xcrud->connection('root','1234','db_utama','localhost', 'latin2');
    $xcrud->table('data_jurnal');
    //..bla bla bla yang isinya nampilin kolom2 dan field di table data_jurnal

    $dokumen = xcrud_get_instance();
    $dokumen->connection('root','1234','db_utama','localhost', 'latin2');
    $dokumen = $xcrud->nested_table('Dokumen','data_jurnal_id','file_jurnal','file_jurnal_id');
    // harusnya nampilin column di bawah field, tapi error

    $data['content'] = $xcrud->render();
        $this->load->view('welcome/xcrud', $data);
}