IMC CANSAS - Sampling Intervals, Filters and Anti-Aliasing

272 Properties of the Modules
imc CANSAS Users Manual - Doc. Version 1.9 - 05.12.2014© 2014 imc Meßsysteme GmbH
6.4.5 Sampling intervals, filters and anti-aliasing
For each of the 8 channels, the sampling interval can be freely set to between 10 ms an 60s. C8 comes
with a hardware-based, permanent anti-aliasing filter, an analog-digital-converter (ADC) using the sigma-
delta method, and finally a digital low-pass filter adapted to the sampling rate.
On: Additional digital low-pass filter.
Off: Switch off the digital low-pass filter. The analog anti-aliasing filter takes always effect.
The table below shows which resulting filter is used.
For temperature measurement (Pt100 and thermocouples):
Sampling rate
Filter
10 ms
Critical damping, 4th order, cutoff frequency 12 Hz
20 ms
Critical damping, 4th order, cutoff frequency 6 Hz
50 ms
Critical damping, 4th order, cutoff frequency 2 Hz
100 ms
Critical damping, 4th order, cutoff frequency 1 Hz
200 ms
Critical damping, 4th order, cutoff frequency 0,5 Hz
500 ms
Critical damping, 4th order, cutoff frequency 0,2 Hz
1s
Critical damping, 4th order, cutoff frequency 0,1 Hz
2s ..60s
Arithmet. mean over the duration of the sampling interval of values sampled at 100 Hz