MS Access database

The values of the variables are saved in a Microsoft Access database.

Access 2000 and Access 2003 (*.mdb) database files are compatible, as are Access 2007 (*.accdb) files. All you have to do is specify different providers in the declaration in the XML configuration file.

Declaration in the TwinCAT Database Server Configurator

Microsoft Access database
DBValueType	Select "Double" to limit logging to alphanumeric and Boolean data types. Select "Bytes" to also log structures and strings.
DBType	Select "MS Access". PLC: eDBType_Access.
DBServer	Not required.
DBProvider	Access 2000 - Access 2003: The provider is "Microsoft.Jet.OLEDB.4.0". Access 2007: The provider is "Microsoft.ACE.OLEDB.12.0".
DBUrl	DBUrl contains the path to the MDB file. e.g. C:\TwinCAT\TcDatabaseSrv\Samples\TestDB.mdb
DBTable	DBTable contains the name of the table.

	Windows CE support Under Windows CE this database is not supported by the TwinCAT Database Server.

	TwinCAT/BSD support This database is not supported by the TwinCAT Database Server on the TwinCAT/BSD platform.

Data type mapping between DB and PLC

E_DBColumnTypes	MS Access	PLC Control
eDBColumn_BigInt	Integer4	DINT
eDBColumn_Integer	Integer2	INT
eDBColumn_SmallInt	Integer2	SINT
eDBColumn_TinyInt	Integer1	SINT
eDBColumn_Bit	YESNO	BYTE
eDBColumn_Money	Currency	LREAL
eDBColumn_Float	Double	LREAL
eDBColumn_Real	Single	REAL
eDBColumn_DateTime	DATETIME	DT
eDBColumn_NText	Text	STRING
eDBColumn_NChar	VarChar	STRING
eDBColumn_Image	OLEOBJECT	ARRAY OF BYTE
eDBColumn_NVarChar	VarChar	STRING
eDBColumn_Binary	OLEOBJECT	ARRAY OF BYTE
eDBColumn_VarBinary	OLEOBJECT	ARRAY OF BYTE

	Data type support WSTRING is not supported by this database. (See WString support)

Notice

Data security

In flash memory devices the number of write access operations is limited. The flash memory devices can fail, with a risk of data loss.

Make regular backups of your system. Use the IPC diagnostics in order to determine the status of the flash memory devices.