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10/06/2016
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Hello Team,
I would like to understand calculation of Maximum Aggregate.
Dataset:
– 00:00:00 20 Raw, Good
– 00:00:20 30 Raw, Uncertain
Configuration:
– TreatUncertainAsBad = False
– PercentDataGood = 100
– PercentDataBad = 100
– SteppedAttribute = False
– UseSlopedExtrapolation = False
Parameters:
– Start = 00:00:00
– End = 00:00:30
– Interval = 00:00:30
Since “5.4.3.11 Maximum” of OPC UA v1.03 specification says in “Calculation Method”:
– If no Bad values then the Status is Good.
– If Bad values exist then the Status is Uncertain_SubNormal.
– If an Uncertain value is greater than the maximum Good value the Status is Uncertain_SubNormal.
Uncertain value (30) is greater than Good value (20), but it must not use value of Uncertain, that’s why I assume that result will be:
00:00:00 20 UncertainDataSubNormal, Calculated, Partial
Calculated is set because of second part of “Calculated” definition: “… OR if the Status was set to Uncertain_SubNormal because of non-Good values in the interval”. Uncertain in non-Good value.
I used https://github.com/OPCFoundati…..ess/Tester to verify my understanding, but it produces:
00:00:00 20 Good, Partial
Please, explain how?
Regards,
Maxim
04/01/2014
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Hi Maxim. This post is related to issue http://opcfoundation-onlineapp…..hp?id=3391 but doesn’t directly affect the outcome.
The result of the Maximum aggregate call on the data you provided would be
00:00:00 20 UncertainDataSubNormal, Calculated, Partial as you describe.
The value is 20 because it is the maximum good value.
The status is UncertainDataSubNormal because a higher value with a quality of not good was skipped.
The status is partial because the last data point in the set is before the end of the interval.
If you can tell me what historian example and what interval you looked at I can check the Aggregate testing tool.
Regards,
Rod
Rod Stein Manager of Technology Matrikon OPC http://www.matrikonopc.com
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