Spectrum Controls Micro850 User Manual page 38

3-16 Chapter 3: Configuring the 2085sc-IF16 Using CCW
Input Range Input Value
+0.000 mA
0-20 mA
+0.000 mA
(IF16C only)
+20.000 mA
+21.000 mA
Filter Selection
17 Hz
4 Hz
62 Hz
470 Hz
User's Manual Pub. 0300306-01 Rev. A
Condition EU ×1
Low Limit 0
Low Range 0
High Range 20000
High Limit 21000
Input ADC Filter Frequencies
The modules use an input ADC digital filter that provides high-frequency noise
rejection for each input signal. The filter setting attenuates the input signal
beginning at the specified frequency.
The filter for each channel is programmable, allowing you to select from four
different filter frequencies:
Index Filter (Hz)
0
1
2
3
Software System Features
The software uses the following channel scan times. The scan time is based on
each channel's Input ADC Filter configuration, and is the sum of the multiplexer
settling time, PGA register setup time, ADC conversion period (which is
[2/filter] + 1 ms), and microcontroller processing overhead.
The module contains two ADC filters and scans two sets of 8 channels in
parallel.
Below is the approximate timing for each input filter selection:
MUX Settling
Time
5 ms
5 ms
5 ms
5 ms
EU ×10
0
0
2000
2100
Note
17 Default
4
62
470
ADC
Conversion
Period
121 ms
481 ms
33 ms
5 ms
Raw Prop Percentage
-32768 0
-32768 0
29646 10000
32767 10500
Processing Total
Overhead Channel
Scan Time
12 ms 138 ms
12 ms 498 ms
12 ms 50 ms
12 ms 22 ms