"dataintegrity" representing Bad value

Module Development
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1

Hello,

Can anyone clarify what the value for dataintegrity should be in the case of a "Bad" value in the database?

According to the Ignition documentation on Quality Codes and Overlays, I believe it should be 512. However, when I attempt to create a new QualityCode using new QualityCode(512), it is reported as "Good".

Looking at QualityCode.VALUE_MAP, I noticed that -2147483136 corresponds to "Bad".

Could someone help clarify this discrepancy?

Thank you
Marius

2

The highest 2 bits of the code indicate the Level.

There are pre-defined static fields in the QualityCode class you should just reference instead, e.g.

QualityCode.Bad

There's a helper function on Level you can use too, e.g.

QualityCode q = new QualityCode(Level.Bad.code(512))
3

So, would it be correct to simply retrieve the dataintegrity value from the table, create a QualityCode object from it, and then directly check if the quality is good or bad?

Iā€™m thinking of something along these lines:

final int dataIntegrity = resultSet.getInt("dataintegrity");
final QualityCode qualityCode = new QualityCode(dataIntegrity);
if (qualityCode.isNotGood()) {
    // Handle bad quality
    ...
}

Does this approach make sense?

4

Yes, assuming that's what is in dataintegrity column. Try it and see :slight_smile:

5

Should the dataintegrity value from sqlt_data_1_2025_01 be interpreted using DataQuality.fromIntValue(someInt) instead of using QualityCode?

I really need to confirm what dataintegrity would contain in the case of a bad value.

Would "Bad" be represented as 512 in the table, or as -2147483647?

6

In 8.1, the Historian system uses HistoricalTagValues, which do use DataQuality, not QualityCode. It'd be best to go from the dataintegrity -> DataQuality -> QualityCode by doing DataQuality::fromIntValue -> DataQuality::getQualityCode.

There isn't a 512 corresponding user code within DataQuality. When storing the DataQuality integer value within the 8.1 Historian implementations, the DataQuality::getQualityFor method is used to determine the matching DataQuality for the given QualityCode (as part of the original QualifiedValue). So, in this example, a Bad(512) QualityCode would return DataQuality.OPC_BAD_DATA, which has an integer value of 0.

Use DataQuality::getQualityCode when reading the data integrity value back out, and call DataQuality::isOpcBadData() to account for bad qualities.

7

I do not think this would work.

The customer has in the table:

timestamp                   dataintegrity
------------------------------------------------------
16/01/2025 9:59:31.071      192
16/01/2025 5:56:30.637      0
16/01/2025 5:56:30.161      192
16/01/2025 1:53:29.456      0

With Ignition 7, dataintegrity = 0 would mean "bad data," but the customer says that in Ignition 8, dataintegrity = 0 would mean "unspecified."

If we use dataintegrity -> DataQuality approach, we get "Bad Quality" for dataintegrity = 0.

  • DataQuality.fromIntValue(0) is shown as "Bad Quality".
  • DataQuality.fromIntValue(192) is shown as "Good" as expected.

However:

  • If we try new QualityCode(0), we get "Good_Unspecified", which I think is correct.
  • new QualityCode(192) is shown as "Good".
  • new QualityCode(193) is shown as "Good(193)".

Do we perhaps need to use dataintegrity -> QualityCode instead?

Thank you,
Marius

8

Sorry for the delayed response.

With Ignition 7, dataintegrity = 0 would mean "bad data," but the customer says that in Ignition 8, dataintegrity = 0 would mean "unspecified."

That isn't true. The quality code you see stored within the customer table is the same in 8.1 as it is in 7.9. A dataintegrity = 600 would be UNKNOWN, whereas a dataintegrity = 0 is OPC_BAD_DATA.

You're confusing the dataintegrity value with QualityCode, which this isn't; it is a DataQuality. An integer value of 0 for QualityCode is Good_Unspecified, but for DataQuality it is OPC_BAD_DATA. Again, all the integer values stored within the dataintegrity table are the 7.9 DataQuality. This was never changed to the new quality system for compatibility purposes.

Values stored within the history system are a HistoricalTagValue. You can see here that the quality model used is DataQuality.

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