Jetter JX2-IO16, User Manual

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JX2-IO16 11.5 Frequency measurement
Jetter AG 89
11.5 Frequency measurement
The JX2-IO16 module supports frequency measurement of counting pulses for the
dual-channel counter and the single-channel counter of input 5. The JX2-IO16
module measures counting pulses which are sensed during an adjustable time base.
Once the time base has elapsed, the JX2-IO16 module subtracts the current reading
of the dual-channel counter or the single-channel counter of input 5 from the reading
which has been sensed last, and calculates the difference by the following formula:
The frequency is calculated in the application program using the following formula:
Read and write access to the time base is made via register array element 9 "Time
base for counter reading difference". The difference in counter readings is read out
of register array element 8 "Counter reading difference - Input 5".
This function is always active, irrespective of the fact whether input 5 is used as
single-channel or dual-channel counter. It is of special interest when using the dual-
channel counter.
Counter reading difference Reading
n
Reading
n 1 –
– =
Frequency (Hz)
Counter reading difference
Time base for counter reading difference x 10 ms
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