5.4.  Database

Database is where an external database system is defined. It can be any ODBC supported SQL database. For instance Microsoft SQL 2014 Express Edition, which is free for 10 GB of data storage.


Any unique name to be referred in Tag or Alarm table.


Additional description.

Connection String

This is a working example for Microsoft SQL 2005 express edition.

In this database connection string, note that the DATABASE parameter need to be modified according to the database created earlier using database creation wizard.

For instance if a database called my_job, meaning the parameter need to be written as "DATABASE=my_job".

Note that for readability reason, the sample was split into lines, in actual scenario, enter the string in one line only.


Example 5.17. Connection String

Extended Properties="DRIVER=SQL Native Client;

Clicking browse button [...] shall launch the Data Link Properties which could Test Connection on the string entered.

More connection strings for other database can be found on this website: http://www.connectionstrings.com/.

Do ensure the ODBC driver for the selected database is installed.

For instance, MySQL ODBC driver can be downloaded from its provider at http://www.mysql.com/downloads/connector/odbc/

[Note] Note

Always use only 32 bit ODBC driver for any brand of database even if the Operating Systems is 64bit.

Log Freq.

Define how frequent a trend data will be logged.

[Tip] Tip

User can create several different databases for different trend data log frequencies.


Define how frequent the server will perform purging sequence.

[Warning] Warning

Purged database is permanently deleted.

Purge Count

Define how long or how big a database shall be kept.

For instance, a value of 90 means data will be stored for 90 days only.

Based on FIFO logic, the 91st day old data will be deleted during purging process.

Purge Type

Always fixed to 'day count' only.

System works on First In First Out basis, i.e. old data will be deleted first.