FB_ALY_StandardDeviation

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.

Syntax

Definition:

FUNCTION_BLOCK FB_ALY_StandardDeviation
VAR_OUTPUT
    ipResultMessage: Tc3_EventLogger.I_TcMessage;
    bError: BOOL;
    bNewResult: BOOL;
    bConfigured: BOOL;
END_VAR

Outputs

Name	Type	Description
ipResultMessage	I_TcMessage	Contains more detailed information on the current return value. This special interface pointer is internally secured so that it is always valid/assigned.
bError	BOOL	This output is `TRUE` if an error occurs.
bNewResult	BOOL	When a new result has been calculated, the output is `TRUE.`
bConfigured	BOOL	Displays `TRUE` when the function block is successfully configured.

Methods

Name	Definition location	Description
Call()	Local	Method for calculating the outputs for a specific configuration.
Configure()	Local	General configuration of the algorithm with its parameterized conditions. The configuration is identical for all channels.
FB_init()	Local	Initializes the number of input channels.
Reset()	Local	Resets all internal states or the calculations performed so far.
SetChannelValue()	Local	Method for passing values to the algorithm.
GetChannelOutputValue()	Local	Method for receiving values from different output channels.

Sample

VAR
    fbStandardDeviation : FB_ALY_StandardDeviation(nNumChannels := 1);
    bUseBesselCorrection : BOOL :=  TRUE;
    eWindowMode : E_ALY_WindowMode := E_ALY_WindowMode.FixWindow;
    nWindowSize : UDINT := 100;
    bConfigure : BOOL := TRUE;
    fInput : LREAL;
    fStandardDeviation : LREAL;
END_VAR

// Configure algorithm
IF bConfigure THEN
    bConfigure := FALSE;
    fbStandardDeviation.Configure(bUseBesselCorrection, eWindowMode, nWindowSize);
END_IF

// Call algorithm
fbStandardDeviation.SetChannelValue(1, fInput);
fbStandardDeviation.Call();
fbStandardDeviation.GetChannelOutputValue(1, fStandardDeviation);

Requirements

Development environment	Target platform	Plc libraries to include
TwinCAT v3.1.4024.0	PC or CX (x64, x86)	Tc3_Analytics

Further Information