Processing Period is 5 µs. The delay time of the moving average filter when the moving aver-
age count is set to 200 times is 995 µs. The delay time is the time until the output of the mov-
ing average filter reaches 100% from 0% when the step signal is input for one moving average
filter.
100
90
80
70
60
50
40
30
20
10
0
250
500
0
750
1000
Amp
lit
u
d
e
[
%
]
Time [µs]
Step signal
Delay time
Moving average
count = 200 times
You can calculate the delay time shown for the step response characteristics using the calcula-
tion formula below. However, the value for the moving average count using the calculation for-
mula below is 1 or higher.
Delay time [µs] = (Moving average count -1) × Digital Filter Processing Period [µs]
The larger the moving average count, the wider range of noise you can remove. This stabilizes
the analog input values, but causes the delay time to increase. When you use the moving
average filter, the analog input values are measured with a delay in response to the input as
shown in the step response characteristics. When the NX bus I/O refreshing is executed in the
middle of digital low-pass filtering, the analog input values in the middle of digital low-pass fil-
tering are sent to the CPU Unit or communications master. Set the moving average count that
is most suitable for the measurement.
8-5-3
Setting Method
This section describes how to configure settings with the Sysmac Studio.
1
Display the Edit Unit Operation Settings Tab Page.
For how to display the tab page, refer to
A-8 Displaying the Edit Unit Operation Settings Tab
2
Enter the set values in the
Digital Low-pass Filter Cutoff Frequency
,
Filter 1 Moving
Average Count
, and
Filter 2 Moving Average Count
for the channel (Ch
£
) you want to set.
Refer to
A-9 Edit Unit Operation Settings Tab Page
on page A - 57 for how to edit the Unit
operation settings.
3
Click the
Transfer to Unit
Button.
8 Functions
8 - 27
NX-series Analog I/O Units User’s Manual for High-speed Analog Input Units (W592)
8-5 Digital Filtering
8
8-5-3
Setting Method
