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All Rights Reserved. Copyright © 2000, Yokogawa Electric Corporation
TI 04L01A01-02E
4.1.4
Rolling average
Taking the rolling average can monitor measured values.
The rolling average can be set on each computation channel.
Interval
: The data stored to the buff every interval time.
Select from 1,2,3,4,5,6,10,12,15,20,30sec,
1,2,3,4,5,6,10,12,15,20,30,60min
Number of average
: Select number of average from 1 to 64.
The same number of data buffers as number of average time are assured for
rolling average
Example: 1 minute rolling average of 10 second samples by DX112 (
Measurement period 1sec
)
Interval
: 10 second
Number of average : 6 (=60 second / 10 second)
Average of the first interval 1
=(S
1
)/1
Average of the second interval 2
=(S
1
+S
2
)/2
Average of the third interval 3
=(S
1
+S
2
+S
3
)/3
Average of the fourth interval 4
=(S
1
+S
2
+S
3
+S
4
)/4
Average of the fifth interval 5
=(S
1
+S
2
+S
3
+S
4
+S
5
)/5
Average of the sixth interval 6
=(S
1
+S
2
+S
3
+S
4
+S
5
+S
6
)/6
Average of the seventh interval 7 =(S
2
+S
3
+S
4
+S
5
+S
6
+S
7
)/6
The difference between the moving average and the rolling average
The moving average is a type of input filter, and is used to suppress the input fluctuation. The moving
average applied at the input becomes the measured data.
The rolling average is a type of computation function that performs a moving average on the input data.
It can also be used to measure the moving average of the computed result. The rolling average can be
used to determine the long-term moving average.
Interval
10 sec
1
0
20
30
S
1
S
2
S
3
40
50
60
70
S
4
S
5
S
6
S
7
Measurement period 1sec
S
7
S
6
S
5
S
4
S
3
S
2
S
1
S
6
S
5
S
4
S
3
S
2
S
1
S
5
S
4
S
3
S
2
S
1
S
4
S
3
S
2
S
1
S
3
S
2
S
1
S
2
S
1
Data buffers
Start computation
1
2
3
4
5
6
7
