Configurar conexão com banco de dados dbexpress

Conexão para Firebird;
SQLConnection.Close;
SQLConnection.Params.Clear;
SQLConnection.ConnectionName := 'ConexaoFirebird;
SQLConnection.DriverName := 'Firebird';
SQLConnection.LibraryName := 'dbxfb.dll';
SQLConnection.VendorLib := 'fbclient.dll';
SQLConnection.GetDriverFunc := 'getSQLDriverINTERBASE';
SQLConnection.Params.Add('User_Name='+Usuario;
SQLConnection.Params.Add('Password='+PassWord;
SQLConnection.Params.Add('Database='+Servidor );
SQLConnection.Params.Add('ServerCharSet=ISO8859_1');
SQLConnection.Open;

Conexão para SQLSErver
SQLConnection.Close;
SQLConnection.Params.Clear;
SQLConnection.ConnectionName := 'ConexaoSQLServer';
SQLConnection.DriverName     :='DevartSQLServer';
SQLConnection.LibraryName    := 'dbexpsda40.dll';
SQLConnection.VendorLib      := 'sqloledb.dll';
SQLConnection.GetDriverFunc  := 'getSQLDriverSQLServer';
SQLConnection.Params.Add('HostName=' + Servidor);
SQLConnection.Params.Add('DataBase='+ BancoDados);
SQLConnection.Params.Add('User_Name='+Usuario);
SQLConnection.Params.Add('Password='+ PassWord);
SQLConnection.Params.Add('MAX_DBPROCESSES=50');
SQLConnection.Open;