e.bloxx D1-1, D1-4
MEASUREMENTS
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HB_EBLOXX-D1_E_V18.doc
Gantner Instruments Test & Measurement GmbH
With the e.bloxx modules frequency measurement is a periodical counter measurement. The counter values for the
actual measurement interval are calculated from the difference to the previous counter values.
The frequency of the measurement signal is calculated as follows:
Frequency f =
n
MI
n …
Number of periods of the measurement signal during the measurement interval MI (measurement counter)
MI …
Measurement interval
If the period of the measurement signal will exceed the measurement interval it is not longer possible to calculate a valid
frequency.
4.5. Digital Input - Frequency Measurement Chronos Method
Picture
4.6 – Frequency Measurement Chronos Method
Picture
4.7 - Signal Diagram of Frequency Measurement Chronos Method
With the e.bloxx modules frequency measurement is a periodical counter measurement. The counter values for the
actual measurement interval are calculated from the difference to the previous counter values. A possible counter
overflow must be considered. The counter width must be dimensioned to guarantee that no overflow is possible during a
measurement interval, max. 100ms for 400kHz signal, max 1s for 60kHz signal.
The e.bloxx has internal counters who count the pulses of the measurement signal (measurement counter) and the
reference signal (reference counter) occurring within the measurement interval MI (given by the interval counter).