Rockwell Automation AB quality Allen-Bradley 1746-INT4 User Manual page 39

Frequency Response of the 8 Hz Filter Converter
Attenuation
00 db
6
-25db
-50db
-75db
-100db
1 5 10
Frequency — Hz
Cut-off Frequencies
Step Response (worst case) for Filter, Multiplexer, and A/D
% of Final Value
100%
90%
80%
70%
60%
6
50%
6
40%
30%
20%
10%
0
50 100
The following table summarizes the input channel characteristics:
Input Channel Characteristics
Corner 50/60 Hz NMR
Frequency
8 Hz 50 ... 60 dB
Effective Resolution of a Channel and Input Device
The effective resolution of an input channel depends upon the type of
input device connected to it.
For thermocouples, we define resolution as the smallest increment of
temperature that can be sampled after A/D conversion. It varies with
temperature and with the type of thermocouple.
We present a resolution graph for each type of thermocouple in
Appendix A, Module Specifications.
Millivolt devices are generally considered linear, and the effective
resolution is that of the channel itself.
Millivolt Devices
Type of Device
Thermocouple
Millivolt Sensor
Preliminary Operating Considerations
Multiplex CJC Values
(200 ms)
60 120 180 240
Time (ms)
Filter Update
Time Time
180 ms 400 ms
Resolution
0.05...0.75 °C @ 300 °C
(32.1...33.4 °F @ 572 °F)
depending on the thermocouple
3.4 µV/bit
Publication 1746-UM614B-EN-P - September 2007
A/D Conversion
(200 ms)
300 360 420 480 540
Step Response
(worst)
600 ms
39
600