Omron SYSMAC C Series Operation Manual page 106

Functions
5-6-3 Averaging
1, 2, 3...
5-6-4 Filtering
! Caution
The averaging function can be used to perform averaging of many samples of
data prior to reporting the value to the CPU Unit. This function is useful for reduc-
ing or eliminating noise commonly found in analog input signals. When averag-
ing is enabled for a particular input point, the Unit takes the requested number of
input samples for that input point and computes an average before reporting
data to the CPU Unit. The average is the algebraic sum of all of the conversions
for the user-specified count divided by the sample count value. Averaging uses a
sequential method as shown below.
1st Reported Value=
2nd Reported Value=
n = number of sample counts, in BCD, specified by the user (minimum of 1, maxi-
mum of 9999)
Unit memory map
location
41
50
103 to 118
To use this function for each input point do the following:
1. Set the input point averaging sample counts value for each input point.
2. Turn ON the averaging enable bit for each input point.
The filtering function is used to filter samples of data prior to reporting the value
to the CPU Unit. The filtering option is similar in function to the averaging func-
tion. While the averaging function is based on a quantity of counts to reach the
data, the filtering function is based on a time. The filtering function is useful for
eliminating aberrations in the data due to noise or stray induced signals.
Unit memory map
location
42
51
87 to 102
To use this function for each input point do the following:
1. Set the input point filtering time constant value for each input point.
2. Turn ON the filtering enable bit for each input point.
When performing filtering, it is recommended that the ladder program perform
READ instructions only. Performing WRIT during filtering may cause long filter-
ing delays due to the constant recalculation of the Unit operating parameters.
Conv + Conv
1
Conv + Conv
n+1 n+2
n
Description
Averaging active flags
Averaging enable bits
Averaging sample counts
Description
Filtering active flags
Filtering enable bits
Filtering constants
Section 5-6
+...+ Conv
2 n
n
+...+ Conv
n+n
Valid data
0 or 1
0 or 1
BCD: 0001 to 9999
Binary: 0001 to 7FFF
Valid data
0 or 1
0 or 1
BCD: 0001 to 9999
Binary: 0001 to 7FFF
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