Reports - Read Tag properties such as engineering units

Hi All,

I have created a tag historian query and added some historical tags. How are tag properties accessed in reports such e.g. engineering units. On the ‘Design’ tab under ‘Data Sources’ the ‘engineering units’ are not exposed?

Hi @davidt, I’m not sure this is possible. Report data is derived from the DB. In the case of a tag historian data source it is simply querying the historian portion of the DB. I don’t think tag parameters are/can be recorded (although my experience with Ignition’s historian is limited).

You may be able to use the SQL Bridge module to record this information then use a SQL query to join all the information together, or just setup the Transaction Groups to do the same as the historian with this added data.

Another solution (if you only need the current value) is to use a script query and then use system.tag.getConfiguration() to get the tag properties. I haven’t tested this so I’m not sure what the performance implications are, or if it is even possible. Hopefully this gives you some more options though :slight_smile:

1 Like

Better than getConfiguration is to just read the tag + subproperty, something like:

All tag properties should be supported:


@PGriffith, thank you for the clarification. I wasn’t sure whether this could be used or not. Good to know :grin: saved me some time testing.