The WorstQuality Aggregate defined in Table 46 returns the worst status of the raw values in the interval where a Bad status is worse than Uncertain, which is worse than Good. No distinction is made between the specific reasons for the status. The server shall ignore the TreatUncertainAsBad for this aggregate.

If multiple values exist with the worst quality the MultipleValues bit is set. If multiple values exist with the worst quality but different StatusCodes then the StatusCode of the first value is returned.

This Aggregate returns the worst StatusCode as the value of the Aggregate.

The timestamp is always the start of the interval. The StatusCodes are Good, Calculated.

Table 46 – WorstQuality Aggregate summary

WorstQuality Aggregate Characteristics

Type

Calculated

Data Type

StatusCode

Use Bounds

None

Timestamp

StartTime

StatusCode Calculations

Calculation Method

Custom

Always Good

Partial

Set Sometimes

If an interval is not a complete interval

Calculated

Set Always

Interpolated

Not Set

Raw

Not Set

Multi Value

Used

StatusCode Common Special Cases

Before Start of Data

Bad_NoData

After End of Data

Bad_NoData

No Start Bound

No special handing required

No End Bound

No special handing required

Bound Bad

No special handing required

Bound Uncertain

No special handing required