Av - Average - Eaton easyE4 Manual

6.1.3.3 AV - Average

Only available on easySoft Version 7.10 or higher.
If this function block is not being shown in the leftmost pane in easySoft 7, make sure
that you are using firmware version 1.10 or higher for the project.
General
easyE4 base devices provide 32 average function blocks, AV01
through AV32. Averaging is a method used to smooth data series,
and is primarily used, for example, to smooth temperatures or pro-
duction data recorded over several hours or days by removing
high frequency components. Please note, however, that this func-
tion block is not intended for signal smoothing or for controllers –
the FT function block should be used in those cases instead.
Operating principle
The average function block takes the values at function block input I1 and calculates
the corresponding moving average. Every time there is a rising edge at function block
input T_, the value at I1 is read and included in the calculation of the average value.
Meanwhile, the maximum number of values to be included in the calculation must be
specified using function block input NO. If this maximum number is reached, there will
be two possibilities depending on the selected operating mode.
One-time mode
When using one-time mode, the function block will stop calculating the average value
when done with the calculation, and function block output RY will be set to 1. This oper-
ating mode is primarily intended for calculating the average of a specific value range at
periodic intervals. Accordingly, it is, for example, suitable for calculating the average
day temperature every day (in which case a value of 24 would be selected for NO). The
maximum absolute error is 0.5.
Continuous mode
When using continuous mode, the function block will continue calculating the average
value with every new rising edge at T_. In this case, the moving average will be cal-
culated for the window defined with NO, with the oldest value being eliminated and the
newest one being added every time there is a rising edge. In other words, this makes it
possible, with every new rising edge, to "look into the past" a number of edges = NO.
Since it is not possible to store all the values in the aforementioned window, the cal-
culation is made with an approximate calculation instead. Please note that, just like with
one-time mode, function block output RY will also be set to 1 in this case as soon as the
number of values NO is reached. This operating mode is suitable, among other things,
for continuously calculating the average value of a temperature for a specific period of
time (and a value of 24 would also be used for NO in this case).
easyE4 10/19 MN050009 EN www.eaton.com
6. Function blocks
6.1 Manufacturer function blocks
317