Exclusive measurement of time is performed as:
·
time (of two successive signal edges)
·
pulse time (time from the beginning of one sampling interval until the next signal edge)
Any other pulses occurring within the sampling interval are not evaluated for these measurement
types.
Determining a frequency and the derivative quantities RPM and velocity is based on the combination
of event counting and time measurement. In other words, during a sampling interval, the number of
events occurring as well as the time interval between the first and last event are measured:
·
frequency
·
speed
·
RPM
The frequency is determined as the number of events counted divided by the time between the first
and the last "complete" event in the interval. An event is complete when a positive edge is succeeded
by a subsequent positive edge.
The frequencies must lie within the bandwidth of the module used. If the maximum frequency is
exceeded during a measurement, the system returns the input range end value instead of the true
measured values.
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