IMC CANSAS - Assignment; Band-Pass Filter

146 Virtual Channels
imc CANSAS Users Manual - Doc. Version 1.9 - 05.12.2014© 2014 imc Meßsysteme GmbH
Data types:
Input channel
Result channel
Integer
Integer
Digital
Digital
4.10.8 Assignment
Parameter
Definition
Input channel
Channel whose sample values are assigned to the result channel
Result channel
The input channel's sample values
Description: The input channel's values are directly assigned to the result channel; the result channel is a
copy of the input channel.
Data types:
Input channel
Result channel
Integer
Integer
Digital
Digital
4.10.9 Band-pass filter
Parameter
Definition
Input channel
Channel to filter
Characteristic
Filter characteristic
Butterworth
Bessel
Chebychev, ripple: 0.5 dB
Chebychev, ripple: 1.0 dB
Chebychev, ripple: 3.0 dB
Lower cut-off frequency
Lower cut-off frequency in Hz
Upper cut-off frequency [Hz]
Upper cut-off frequency in Hz
Result
Filtered input channel.
Description: Filtering of the input channel with a band-pass filter. A bilinear transformation is used to
compute the filter coefficients from the other parameters. The filter applied is always a 4th order band-
pass filter.
Notes: A condition for effective filtering is that the cut-off frequencies are significantly below half of the
input channel's sampling rate. The closer the cut-off frequencies are to the input channel's sampling rate,
the more imprecise the filter's amplitude response.
The cut-off frequency's input range depends on the input channel's sampling rate, the filter's order and
on the filter characteristic.