Part 13 of the Standard contains some sample Aggregate results in Annex A. The raw input values for the Historian 1 sample are:

Code:
Timestamp Value StatusCode
12:00:00 - Bad_NoData
12:00:10 10 Raw, Good
12:00:20 20 Raw, Good
12:00:30 30 Raw, Good
12:00:40 40 Raw, Bad
12:00:50 50 Raw, Good
12:01:00 60 Raw, Good
12:01:10 70 Raw, Uncertain
12:01:20 80 Raw, Good
12:01:30 90 Raw, Good
null No Data

The example from Annex A / Historian 1 for the Range Aggregate has the result:

Code:
Historian1
Timestamp Value StatusCode Notes
12:00:00.000 0 Good, Calculated, Partial
12:00:16.000 10 Good, Calculated
12:00:32.000 BadNoData
12:00:48.000 10 Good, Calculated
12:01:04.000 BadNoData
12:01:20.000 10 Good, Calculated, Partial
12:01:36.000 BadNoData

Notice the 3rd interval from 12:00:32 to 12:00:48 has quality BadNoData, because there is no Good value in that interval. Everything is fine here.

Now, consider the Delta Aggregate description:

Quote:
The Delta Aggregate retrieves the difference between the earliest and latest good raw values in the interval. The aggregate is negative if the latest value is less than the earliest value. The status is Uncertain_DataSubNormal if non-good values are skipped while looking for the first or last values. The status is Good otherwise. The status is Bad_NoData if no good raw values exist.

Notice that " The status is Bad_NoData if no good raw values exist", much like the Range Aggregate.

But the sample result from Annex A shows:

Code:
Historian1
Timestamp Value StatusCode Notes
12:00:00.000 0 Good, Calculated, Partial
12:00:16.000 10 Good, Calculated
12:00:32.000 0 UncertainDataSubNormal, Calculated
12:00:48.000 10 Good, Calculated
12:01:04.000 0 UncertainDataSubNormal, Calculated
12:01:20.000 10 Good, Calculated, Partial
12:01:36.000 BadNoData

Why is the third interval UncertainDataSubNormal, if the only raw value from that interval has Bad quality (Value 40)?