Better handle incompatible data type event in PI Vision trend

Scenario: Your company has a PI tag set up as string that primarily gets float values. It is a string because it sometimes contains messages explaining why a result was not obtained. The tag is set up as a double attribute in AF and plotted in Vision. This works fine unless a non-numeric value is encountered within the Time Range you are looking at. If this happens, the trend is blank and No Data is displayed. While PI annotations would have been a good use in this situation, it is difficult to go back and change this when you have many different tags with lots of historical data. It would be better if an incompatible data type event was handled like a system digital state and create a data gap instead. Workaround: Create an Analysis that uses the Double() function to convert events to double. This creates a Calc Failed event when the event can't be converted to double.