When Exporting Data from a multi-history chart there are many nan's in the data

Issue

When "Exporting Data" from a multi-history chart there are many nan's in the data.

Product Line

TAC I/A Series

Environment

I/A Series G3 (Niagara)

Cause

The timestamp in the history data has a millisecond component that is not shown on the data displays.  When the Export data is displayed history values are provided with the timestamp.  If the timestamps for all the histories samples are exactly the same (to the millisecond) the data value is displayed, if not "nan" is displayed. 

Resolution

This condition occurs only when the "rollup" for the chart is left at the default of none.  Changing the "rollup" to a value other than none will bring the data into order.  Setting the rollup to the sample interval of the histories gives the best results in the Export data.