Bosch C60 Manual page 49

9.3.6 Configuring a frequency input
Bosch Motorsport
Cut-off frequency automatically adjusted to recording rate
Example:
– 100 Hz recording rate (10 ms)
– < 40 Hz pass band (> 99 %)
– 50 Hz stop band (< 1 %)
Linear phase – no signal distortion
10000Hz Abtastrate
2
1.5
Wert 1
0.5
0
-0.5
-1
-1.5
-2
0 500 1000 1500 2000 2500 3000
Abtastwerte (roh)
Sensor signal with noise
Latency compensation – no filter delay in recorded data
– Filtering is (smart) averaging over several samples
– Filtered signal is delayed with respect to real time signal
– C 60 filters have constant, frequency independent delay
– Delay (e.g. 22 samples at 10 ms) is corrected during recording
– No delay filtered vs. unfiltered in recorded data
– Correction is (of course) not possible for real time data (display, online, PWM out)
– Use filtered data for recording, use unfiltered data for real-time
This function requires the installation of Software Upgrade 1.
Example: measurement of wheel speed
– Pulse wheel attached to wheel
– Each passing tooth of pulse wheel triggers hall sensor
– Calculation of wheel speed with wheel circumference
Data_Logger_C_60_Manual
Analog and Frequency Inputs | 9
100Hz Abtastrate
1.5
1
Wert
0.5
Recorded signal 100Hz
0
(unfiltered)
-0.5
-1
-1.5
0 5 10 15 20 25 30
Abtastwerte (dezimiert)
100Hz Abtastrate
1.5
1
Wert
0.5
Recorded signal 100Hz
0
(filtered)
-0.5
-1
-1.5
0 5 10 15 20 25 30
Abtastwerte (gefiltert)
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