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Very often there are tags with steps in the process, these steps are numbers and TrendMiner take them as default as analog data, hence it interpolates the steps with the numbers, e.g. line flushing, step 100; Production, step 200, duration of line flushing 20 minutes, then start in 100, changing 101, 102...200 during those 20 minutes, when actually more than numbers are labels (texts). 

Is it possible to change the tag from a analog signal to digital? or avoid the interpolation, otherwise in a VBS looking for a flushing (100) or production (200) the results are fractions of minutes. 

Thanks. 

Since TrendMiner takes the interpolation type from the historian, I would say this is a misconfiguration issue that ideally would be solved in the historian itself. Then it is fixed once and for all for all applications that depend on the historian data. One thing to keep in mind here is that whenever the tag type is changed in the historian, an admin needs to re-index the tag and restart the tm-compute service (causes a few minutes of downtime) for it to catch on in TrendMiner. Also you should re-create saved searches that depend on this tag, as the interpolation type of the underlying tags is saved as metadata to the searches.

 

As it is not always straightforward to have a tag type corrected on the historian (administration, dependencies, ...), I do understand your idea to have a workaround in TrendMiner. There is no way to overwrite the tag interpolation in the value-based search. I also do not see a way to use the tag builder formulas to convert a tag into a stepped version, as formula tags are always analog (you can sometimes make them appear stepped by putting the points in the right places, but that is not an option here). I do see an option with the new custom calculation feature, as there you can select the output tag type and 'simply' load the tag data and output it again under a stepped interpolation. This is a complex feature that requires an additional license though. If you were to already have access to this feature, you could consider using this as a quick hack for a one-time analysis. Anything more permanent I would strongly recommend going through the effort of fixing the type in the historian.

 

More information on how TrendMiner determines the tag type can be found here: https://documentation.trendminer.com/en/how-does-trendminer-determine-tag-type-.html

For Generic ODBC connections, a type mapping can be configured: https://documentation.trendminer.com/en/how-to-set-up-a-generic-odbc-data-source-.html

(older ODBC connections also provide an option to do this: https://documentation.trendminer.com/en/how-to-set-up-an-odbc-oledb-sqlite-data-source-.html)

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