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Flow-X─ Function Reference
Flow-X General functions - fxPeriodFWA
fxPeriodFWA
Description
The function calculates a flow-weighted average (FWA) for a particular period.
The function weights the input value with a flow increment and updates the average accordingly. The
flow increment is provided by a ‘TotalizerDelta’ or ‘TotalizerRate’ function.
At the end of the period the current average is stored in the previous value and the current value is
reset to 0.
Inputs and outputs
Function
inputs
Remark
EU
SW
tag
Range
Default
Name
Name used for tag prefix and
retentive storage.
Input value
Value to be averaged
Same as
linked cell
Enabled
0:
Disabled
<> 0:
Enabled
EN
Increment
Flow increment with which the
input value is weighed.
Must refer to the corresponding
output from a 'TotalizerRate' or
'TotalizerDelta' function
Negative values will be ignored.
Same as
linked cell
Period type
Type of period:
1: Second
2: Minute
3: Hour
4: Day
5: Week
6: Month
7: Quarter
8: Year
TYP
Period count
Number of periods (e.g. 5 minutes,
8 hours)
CNT
1..1e11
Period start
Absolute start date and time of
the period. This will be used as the
reference point to calculate the
next period rollover from.
The value may be defined in the
past or the future. The next
rollover period will be calculated
accordingly (so forwards or
backwards in time).
START
<DATETIME>
Function outputs
Remark
EU
SW tag
Alarm
Fallback
Current average
Average calculated over the
current period.
Same as input
‘Input value’
CUR
0
Previous average
Average of the previous period.
Same as input
‘Input value’
PRV
0
Pre-previous
average
Average of the pre-previous
period (i.e. the period before
the previous period).
Same as input
‘Input value’
PPRV
0
Summary of Contents for flow-x
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