Standard Deviation

The Standard Deviation algorithm calculates the empirical standard deviation for a configurable number of input channels. The number of input data to be included in the calculation and the type of calculation can be configured.

Optionally, a Boolean signal can be selected for the Enable Execution input so that the algorithm is only active if the value of the selected signal is TRUE.

Configuration options

• Num Channels: Configuration of the number of independent input and output channels.
• Use Bessel Correction: If the checkbox is checked, Bessel's correction is applied. This parameter must be enabled in order to obtain an expected result for random samples.

The empirical standard deviation, without Bessel's correction

The empirical standard deviation, with Bessel's correction

• Window Mode: Window mode used. Influences the amount of input data included in the calculation and the timing of the calculations.
  Continuous: All input values since the start of the algorithm are included in the calculation. The calculation is performed cyclically.
  Fix Window: Only the last N input values are included in the calculation. The calculation is performed every N calls.
  Sliding Window: Only the last N input values are included in the calculation. The calculation is performed cyclically.
• Window Size: The number of values N that are included in the calculation can be configured depending on the window mode used. With the window mode Continuous this parameter is ignored.

Output values

• Standard Deviation 00..n: Empirical standard deviation of the input channels.

Standard HMI Controls

For the Standard Deviation algorithm, the following HMI controls are available for generating an Analytics Dashboard:

1. The Table Control or Multivalue Control visualizes all output values: Standard Deviation Results.

Alternatively, customer-specific HMI controls can be mapped in the Standard Deviation algorithm using the Mapping Wizard.