I have a PI tag that brings data from an Oracle database through OLEDB COM Connector and an AF attribute based on a custom AF DataRefence that brings data from the same Oracle database using the same functions ("stored procedures").
If I bring both to a ProcessBook trend, they return the same data, but for the PI tag, the first value appears connected to the previous value (the first value before the trend´s start time), while for the AF attribute, it doesn´t.
Here are some screenshots to illustrate the issue:
The upper trend shows the AF attribute, and the lower trend shows the PI tag. The upper trend is selected, and the Details pane on the right side of the screen shows that there are 159 values in the timerange, and the first timestamp is 05-sep-11 19:26:23. Now let´s select the lower trend:
As we can see, there are also 159 values and the first timestamp is also 05-sep-11 19:26:23. Now let´s unselect both trends, click on the timerange scroller on the toolbar to move both trends back in time, then select the lower trend again:
A few more values appear on the left of both trends, and again, the first value is connected to the previous value only on the lower trend (PI tag).
Does anyone know how to correct this?