Chapter 5
28
Configuring the STP9820
The STP9820 provides two user-configurable features:
• Changing the cutoff frequency of the input filters, described in
the next section, and
• Installing a relay driver for use with the digital output lines on
the DT9820 Series function modules, described on
Once you have configured the STP9820 for your needs, continue with
the instructions on
Changing the Input Filter Cutoff Frequency
By default, the DT9820 Series modules use dual RC low-pass input
filters for each analog input channel with a cutoff frequency of
100 Hz. Through software, you can turn these input filters on or off;
they are off by default. If the filter cutoff frequency is suitable for
your needs, skip the rest of this section and continue with the
instructions on
.
If, however, the filter cutoff frequency is not suitable for your needs,
you can decrease the cutoff frequency by increasing the series input
resistor values on the STP9820 screw terminal panel. The formula that
describes this relationship is as follows:
where,
Fc is the cutoff frequency of the filter,
R is the resistor value,
Fc
1
2
π
( )
⁄
R
1500
+
(
)
0.000001
(
)
=
Summary of Contents for DT9820 Series
Page 1: ...DT9820 Series UM 18219 B Getting Started Manual...
Page 20: ...Chapter 2 12...
