FAQ/024 KAM-500: What is the real sampling frequency of a parameter that goes to different destinations at different rates? What is the real cut-off frequency of the filter?
August 18, 2014
To know the real sampling frequency of a parameter when there is more than one "Sink" in the system (PCMs, Ethernets or CompactFlash Memory module), all the "Sinks" where this parameter is going to have to be considered. The real sampling frequency will be the highest i.e. if the same parameter mentioned above is sent at 50 Hz in the PCM Frame is logged into a CompactFlash Memory at 400 Hz, the real sampling frequency for the parameter will be 400 Hz.
In the last example, if a parameter coming from an Analog Module has the cutoff frequency set to Fs/4, the real cut-off frequency of the filter will be 400/4=100 Hz (as opposed to the 12.5 Hz that you’d expect if looking only at the PCM Sampling Rate). 23