Mitsubishi NZ2GFCF-D62PD2 User Manual page 151

● Whichever mode ("1: 1-Phase Multiple of 2", "4: 2-Phase Multiple of 2", or "5: 2-Phase Multiple of 4") is set in "CH Pulse
input mode" (
● When "1: 1-Phase Multiple of 2" is set in "CH Pulse input mode" (
in phase A is 10kHz (10000 per second), the measured frequency value becomes 20kHz since the pulse count is
regarded as 20000 based on the calculation below.
Pulse count = 10000 (pulse) × 2 = 20000 (pulse/s)
● Measurable frequency (minimum)
The frequency is calculated from the count value per unit of time. However, the frequency smaller than the one in the
following table cannot be measured correctly as the count value is in an integer number.
1s
0.1s
0.01s
When a unit of time is 0.01s and the input frequency is 1234Hz, the measured frequency value is 1200Hz or 1300Hz. By
doing the moving average count, the fluctuation of the measured values can be lowered.
(4) 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.
Set the number of the moving average count to CH Moving average count (Frequency measurement) (RWw19,
RWw31).
Setting item
CH Moving average count (Frequency measurement)
(RWw19, RWw31)
After the specified number of counts are done, the average of the measured frequency values is stored in CH
Measured frequency value (RWr1A to RWr1B, RWr32 to RWr33) as shown below.
When the number for CH Moving average count (Frequency measurement) (RWw19, RWw31) is set to
Ex.
3
CH Count enable command
Page 92, Section 8.1.1), the frequency (Hz) is calculated based on the count value per unit of time.
Unit of time
(RY24, RY3C)
T T T
10000
2)
Frequency
1)
5000
0
1st storage = 1)+2)+3)/3 = (5000+7000+8000)/3
2nd storage = 2)+3)+4)/3 = (7000+8000+8000)/3
3rd storage = 3)+4)+5)/3 = (8000+8000+4000)/3
Page 92, Section 8.1.1) and the input frequency
Measurable frequency (minimum)
1Hz
10Hz
100Hz
Setting range
1 to 100
(When 1 is set, the operation is performed
with the moving average count regarded as
not being done.)
T T
3) 4)
5)
1st storage
2nd storage
3rd storage
Time
6667
7667
6667
CHAPTER 8 FUNCTIONS
Reference
Page 265, Appendix 2 (12)
Remote register
CH Measured
frequency value
(RWr1A to RWr1B,
RWr32 to RWr33)
T: Time unit
8
149