php - Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[HY000] -

i getting error when tring connect mssql server linux php.

fatal error: uncaught exception 'pdoexception' message 'sqlstate[hy000]: general error: 10007 unicode data in unicode-only collation or ntext data cannot sent clients using db-library (such isql) or odbc version 3.7 or earlier. [10007] (severity 5) 

here connection codes:

error_reporting(e_error);

$dsn='mssql:host=***;dbname=***;';       $username='***'; $passwd='***';  try{  $baglanti=new pdo($dsn,$username,$passwd); $baglanti->setattribute(pdo::attr_errmode,pdo::errmode_exception);     }catch(pdoexception $e){        echo 'error:'.$e->getmessage(); } 

how can solve issue?

thanks.