ABB 800xA Operation page 97

Section 8 Control Loop Asset Monitor (CLAM)
Sl.No Name
5. Standard Deviation
Controller Output
6. Skewness Control
Error
7. Kurtosis Control
Error
8. Data Compression
Index
9. Data Quantization
Index
3BUA000150-600
Table 9. Indices used in CLAM
Description
Calculates the standard deviation of the
controller output. The result is a measure of the
control effort to keep the loop under automatic
control. Result in the interval [0-100 %].Very
large values usually indicates a loop problem.
Calculates the third central moment divided by
the cube of the standard deviation. This is a
measurement of asymmetry around the mean.
This is an important indicator of control
problems and should nominally be close to zero
(significant outside [-1,1]).
Calculates the forth central moment divided by
the forth power of the standard deviation. It is a
measurement of how outlier-prone a
distribution is.
A normal distribution has k=0. Good values
within [-1.5,1.5].
Quantifies the amount of compression in the
data by looking for linear segments. Nominal
values below 3. Used to decide if the data is
reliable. [0-inf].
Quantifies the amount of quantization in the
data. [0-100%]. Usually acceptable if result
below 40 %.
Performance indices
Index class
Basic statistics
Basic statistics
Basic statistics
Data validity
Data validity
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