Rockwell Automation 1769-IT6 Compact I/O 1769-IT6 Thermocouple/mV Input Module - Manual (Page 49)

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
1 5 .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 1150 750 500 250
65 .5 Hz
900
–3 dB
3000 0 2500 1500 1000 500
1 31 Hz
2000
–3 dB
6K 0 5K 3K 2K 1K
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)
G
ain
(d
B)
Gain (dB)
1000 Hz Input Filter Frequency
Frequency (Hz)
Gain (dB)
60 Hz Input Filter Frequency
Frequency (Hz)
G
ain (dB)