Confidence()

Format

Confidence(Arg1)

Returns

Returns the confidence of the supplied argument, as an integer value from 0 to 100 (a percentage).

Inputs

Arg1: The argument being evaluated.
Behaviour: Required
Dimension: Collection, SingleValue, MultiCollection
Valid data types: Null, Boolean, DateTime, Decimal, Integer, String, Duration, Error

How to format data types

Formula

The confidence of tag values is taken from the underlying historian, with the Adaptor mapping the historian's "data quality" value to a confidence. For example, some historians report a confidence as a percentage directly, whereas others have a status (such as good or bad) which is mapped to a value of 100 or 0 respectively.

For sample-based historical functions (Sum_Sampled(), Average_Sampled(), Max_Sampled(), Min_Sampled(), Count_Sampled()), the confidence of the result is the arithmetic mean of the confidence of the input samples in the Expr argument. That is:

((sample 1 confidence) + (sample 2 confidence) + … + (sample N confidence)) / (N, the number of samples 
in interval)

For continuous historical functions (Integral_Sampled(), ContinuousMax_Sampled(), ContinuousMin_Sampled(), and TimeWeightedAverage_Sampled()), the confidence of the result is the time-weighted average of the confidence of the input data in the Expr argument. That is:

((sample 1 confidence) * (time sample 1 in effect in interval) + (sample 2 confidence) * (time sample 2 in 
effect in interval) + … + (sample N confidence) * (time sample N in effect in interval)) / (total time 
of interval)

For all other functions (such as Sin(Expr), Expr1+ Expr2, and so on) the confidence of the result is the minimum of the confidences of all of the arguments.

Release History

• Confidence() 4.6.5
  • Changed Arg1 parameter to support MultiCollection values.
• Confidence() 4.0
  • Initial version