Microsoft Access Database
The values of the variables are saved in a Microsoft Access database.
Database files of Access 2000 and Access 2003 (*.mdb) are as compatible as database files of Access 2007 (*.accdb).
You only must declare different provider in the XML - configuration file for these different filetypes. More info at "Declaration different databases"
The variable values are saved in the following table structure.
Column name | Data type | Characteristic |
|---|---|---|
ID | AutoNumber | Field Size:= "Long Integer"; New Values:= "Increment" |
Timestamp | Date/Time | Format:= "General Date" |
Name | Text |
|
ValueType="Double" | ||
Value | Number | Field Size:= "Double" |
ValueType="Bytes" | ||
Value | OLE Object |
|
An AutoID is generated in the "ID" column. The value in this column is, in other words, always increased by 1.
The "Timestamp" column stores the time at which the data record was saved.
The name of the variable is stored in the "Name" column
The "Value" column stores the value of the variable.
E_DBColumnTypes | MS Access | PLC Control |
|---|---|---|
eDBColumn_BigInt | Integer4 | DINT |
eDBColumn_Integer | Integer2 | INT |
eDBColumn_SmallInt | Integer2 | INT |
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 |
Notice | |
Compact Flash Card Lifetime Do not save the database on the Compact Flash Card in case of an embedded system. |