Spectrum Controls 1769sc-HART Modules User Manual
Page 60
Compact IO™ Isolated HART Analog Input Module
User's Manual 0300215-03 Rev. A
6-10
Figure 6-2 (Frequency Response)
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.
28.5Hz Filter
-120
-100
-80
-60
-40
-20
0
0
10
20
30
40
50
60
70
80
90
F
ilt
e
r Re
je
c
tio
n
(
d
B)
50 Hz Filter
-120
-100
-80
-60
-40
-20
0
0
20
40
60
80
100
120
140
160
Fi
lt
e
r R
e
je
c
tion
(
d
B
)
60Hz Filter Ope ration
-120
-100
-80
-60
-40
-20
0
0
50
100
150
200
F
il
ter
R
e
ject
io
n
(
d
B
)
300Hz Filter Oper ation
-120
-100
-80
-60
-40
-20
0
0
200
400
600
800
1000
F
il
ter
R
e
ject
io
n
(
d
B
)
360Hz Filter Operation
-120
-100
-80
-60
-40
-20
0
0
200
400
600
800
1000
1200
Fi
lt
e
r R
e
je
c
tion
(d
B
)