METEK GmbH uSonic-2 23
3.3.4 Averaging time and sampling frequency
The averaging time and the sampling frequency are configured with the
commands AT, AV and SF.
Sampling frequency
One measuring cycle (every ultrasonic transducer transmits and receives one
time) takes 20ms. The command SF configures, how many measuring cycles will
execute in 1000s.
The possible setting is 4000…40000, analog to 4…40Hz.
Averaging time
The command AT defines the averaging time. The uSonic-2 accumulates in this
time an averaged value of the the measured values. At the end of this time the
uSonic-2 displays the averaged value at the serial interface and refreshes the
analog output signals.
The possible setting is 1…3600, analog to 1s…3600s.
Coherent averaging
The command AV defines, if and how many measured values will averaged
coherent. The coherent averaging function averages the measured signals
directly, before sending these results to the processor. The coherent averaging is
recommended for high wind speed application.
The possible setting is 1…32.
If AV=1, every measuring cycle will be processed individually and averaged
depending on AT.
Example:
AV=1, AT=0, SF=25000
Raw data (25Hz) will be displayed at the serial interface.
AV=1, AT=600, SF=10000
Measuring with 10Hz and display values after averaging 600s.
If AV>1, the measuring cycles will be averaged coherent corresponding AV.
These results will be averaged corresponding AT.
To Next Page
