User`s manual

147
CHAPTER 4 FUNCTION
4
4.13 Frequency Measurement Function
(4) Measurable frequency (minimum)
The frequency, which is calculated from the count value per a unit of time, should be the value with which the
calculated count value becomes an integer number. Therefore, the frequency smaller than the one in the
following table cannot be measured correctly.
For measurement, input the frequency shown below or higher.
In case a unit of time is 0.01s and the input frequency is 1234Hz, measured frequency value becomes
1200Hz or 1300Hz.
By doing the moving average count, the fluctuation of the measured values can be lowered.
(5) Moving average count
When the frequency measurement function is used, the fluctuation of the measured frequency values can be
lowered by doing the moving average count.
The number of the moving average count is set to CH1 Moving average count (frequency measurement)
(Un\G1101).
After the specified number of counts are done, the average of the measured frequency values is stored in CH1
Measured frequency value (Un\G1132, Un\G1133).
In case the number of moving average count is set to 3
A unit of time Measurable frequency (minimum)
1s 1Hz
0.1s 10Hz
0.01s 100Hz
Setting item Setting contents Reference
CH1 Moving average count (frequency measurement)
(Un\G1101)
Set the number of moving average count in the
range of 1 to 100.
When 1 (default value) is set, the operation is
performed with the moving average count regarded
as not being done.
Page 82, Section 3.4.2 (48)
Ex.
Ex.
CH1 Count enable command
(Y06)
Frequency
10000
T
1)
2)
3) 4)
5)
T
5000
0 Time
T: Time unit
1st storage
1st storage = 1)+2)+3)/3
2nd storage = 2)+3)+4)/3
3rd storage =3)+4)+5)/3
Buffer memory
CH1 Measured
frequency value
(Un\G1132, Un\G1133)
2nd storage
3rd storage