User Manual

Rockwell Automation Publication 1769-UM004B-EN-P - March 2010 49
Module Data, Status, and Channel Configuration Chapter 4
Figure 4 - Frequency Response Graphs
The cut-off frequency for each channel is defined by its filter frequency selection.
Choose a filter frequency so that your fastest changing signal is below that of the
filter’s cut-off frequency. The cut-off frequency should not be confused with the
update time. The cut-off frequency relates to how the digital filter attenuates
frequency components of the input signal. The update time defines the rate at
which an input channel is scanned and its channel data word is updated.
–3 dB
360
0
300
180
120
60
15.72 Hz
240
–3 dB
60
0
50
30
20
10
2.62 Hz
40
–3 dB
300
0
250
150
100
50
13. 1 Hz
200
0
–40
–60
–80
-100
-120
-140
-160
-180
- 200
–20
0
–40
–60
–80
-100
-120
-140
-160
-180
- 200
–20
0
–40
–60
–80
-100
-120
-140
-160
-180
- 200
–20
0
–40
–60
–80
-100
-120
-140
-160
-180
- 200
–20
0
–40
–60
–80
-100
-120
-140
-160
-180
- 200
–20
0
–40
–60
–80
-100
-120
-140
-160
-180
- 200
–20
–3 dB
1300
0
1150750500250
65 .5 Hz
900
–3 dB
30000 250015001000500
131 Hz
2000
–3 dB
6K
0
5K3K2K1K
262 Hz
4K
10 Hz Input Filter Frequency 50 Hz Input Filter Frequency
250 Hz Input Filter Frequency
500 Hz Input Filter Frequency
Frequency (Hz) Frequency (Hz)
Frequency (Hz)
Frequency (Hz)
Gain (dB) Gain (dB)
Gain (dB)
Gain (dB)
1000 Hz Input Filter Frequency
Frequency (Hz)
Gain (dB)
60 Hz Input Filter Frequency
Frequency (Hz)
Gain (dB)