Learn about InstrumentTag (SQL query file) - RDBMS

The InstrumentTag attribute specifies the file containing the SQL statements that determine the data to be read from or written to PI points (or points/PI tags/tags). The query executes when changing an attribute and executing a tag.

To configure the folder where query files are stored, use PI ICU by going to the pointsource > Startup Parameters tab and setting the SQL Files Directory field. As an alternative to specifying queries in text files, you can specify the query in the tag's ExDesc attribute.

Note: If you change the query in the ExDesc attribute, you do not need to restart the interface to enable it to execute the revised query. However, if you change the query in SQL files, you need to either restart the interface or modify the associated tag's attributes to execute the revised query.

InstrumentTag Length

Depending on the version of PI API and the PI Data Archive, this interface supports an InstrumentTag attribute whose length is at most 32 or 1023 characters.