AverageTimeCal

AverageTimeCal (FB)

FUNCTION_BLOCK AverageTimeCal

Short description

Calculation of the average of an analog value over four different time periods Averaging: Weighted average (see formula below) Typical application: Temporal averaging of the outside temperature

Representation

Interfaces

Inputs

Name	Data type	Value range	Initial value	Function
rIn	REAL			Analog value input

Outputs

Name	Data type	Value range	Initial value	Function
rOutCH0	REAL			Average value period 1
rOutCH1	REAL			Average value period 2
rOutCH2	REAL			Average value period 3
rOutCH3	REAL			Average value period 4
rOutMin	REAL			Minimum of all measurements
rOutMax	REAL			Maximum of all measurements
dtLastNewValue	DATE_AND_TIME			Storage timestamp of the last measurement
sErr	STRING			Current error text

Setpoints / parameters

Name	Data type	Value range	Initial value	Function
xCalculation	BOOL		TRUE	Enable / disable data recording
xResetOnInput	BOOL		FALSE	Initialization of the measurement storage and the average value outputs with rIn
rInitValue	REAL		10	Initialization value for the measurement storage and the average value outputs when eInitial = eInit2.InitValue.
tInitDelay	TIME		5s	Delay time for measurement storage when eInitial = eInit2.InputValueDelayed.
eInitial	eInit2		eInit2.LastValue	Specification of the type of initialization
wCH3Time	WORD		48	Definition of period 4 in hours
wCH2Time	WORD		36	Definition of period 3 in hours
wCH1Time	WORD		24	Definition of period 2 in hours
wCH0Time	WORD		12	Definition of period 1 in hours
wInterval	WORD		15	Definition of the recording interval in minutes

Function description

General

Averaging The value at the analog input rIn is captured recording interval iInterval (Default = 15 minutes) is recorded. To calculate the average of a period X (X = 0 … 3), three factors are determined for each period. Factor 1 - Period X: Total number of measured values to be considered Factor 1 = ( iCHXTime * 60 ) / iInterval Factor 2 - Period X: Factor for the stored average Factor 2 = ( Factor 1 - 1 ) / Factor 1 Factor 3 - Period X: Factor for the current value at the analog input rIn Factor 3 = 1 - Factor 2 The average of each period is calculated at the recording interval iInterval according to the following formula and transferred to the average value outputs: Average = (Old average * Factor 2) + (rIn * Factor 3) Legend: X = 0 … 3

Example

iInterval = 15 minutes, wCH0Time = 12 hours, Old average = 20.0, rIn = 22.0 Factor 1 = 48 Factor 2 = 47 / 48 Factor 3 = 1 / 48 Average = 20.041

Average value outputs rOutCHX (X = 0 … 3)

At the average value output rOutCHX (X = 0 … 3) the correct arithmetic mean of the corresponding entries in the measurement value storage is available for the first time after the duration iCHXTime the average of the captured input values is available.

Minimum value output rOutMin

At the minimum value output rOutMin is available for the first time after one recording interval iInterval the absolute minimum of all captured input values is available.

Maximum value output rOutMax

At the maximum value output rOutMax is available for the first time after one recording interval iInterval the absolute maximum of all captured input values is available.

Timestamp dtLastNewValue

At the timestamp output dtLastNewValue is available for the first time after one recording interval iInterval the timestamp of the last entry in the measured value memory is available.

Error text sErr

At the output for the current error text sErr a descriptive text is available in case of error. If there is no error, an empty string is output.

Type of initialization eInitial

This setpoint / parameter determines the type of initialization of the measurement storage and the average value outputs. The following options are possible:

Type	Initialization value	Note
eInit2.InitValue	rInitValue	Configurable initial value
eInit2.InputValue	rIn	Input value
eInit2.InputValueDelayed	rIn	Delayed input value
eInit2.LastValue	Average - measurement value storage (measurement value storage filled)	Last value
eInit2.LastValue	rIn (measurement value storage empty)	Last value

Enable / disable data recording xCalculation

This setpoint / parameter enables (= TRUE) or disables (= FALSE) data recording

Reset of the measurement value storage / the average value outputs xResetOnInput

With this setpoint / parameter the measured value memory / the average value outputs are set to the value rIn reset (= TRUE).

CODESYS

InOut:

Scope	Name	Type	Initial
Input	rIn	REAL
Input Const	xCalculation	BOOL	TRUE
Input Const	xResetOnInput	BOOL	FALSE
Input Const	rInitValue	REAL	10
Input Const	tInitDelay	TIME	TIME#5s0ms
Input Const	eInitial	eInit2	eInit2.LastValue
Input Const	wCH3Time	WORD	48
Input Const	wCH2Time	WORD	36
Input Const	wCH1Time	WORD	24
Input Const	wCH0Time	WORD	12
Input Const	wInterval	WORD	15
Output	rOutCH0	REAL
Output	rOutCH1	REAL
Output	rOutCH2	REAL
Output	rOutCH3	REAL
Output	rOutMin	REAL
Output	rOutMax	REAL
Output	dtLastNewValue	DT
Output	sErr	STRING