Mitsubishi Electric NZ2GFCF-D62PD2 User Manual page 167

No.
The following processing is performed when CH Count enable command (RY24, RY3C) is turned on to turn CH Frequency
measurement flag (RWr20.b4, RWr38.b4) to Operating (1).
• The values in CH Time unit setting (Frequency measurement) (RWw18, RWw30) and CH Moving average count
1) (Frequency measurement) (RWw19, RWw31) are acquired. (If the value is changed during the frequency measurement, the
change is ignored.)
• CH Update flag (Measured frequency value) (RX2D, RX45) turns off.
• The value in CH Measured frequency value (RWr1A to RWr1B, RWr32 to RWr33) is cleared to 0.
CH Update flag (Measured frequency value) (RX2D, RX45) turns on when a value is stored in CH Measured frequency value
2)
(RWr1A to RWr1B, RWr32 to RWr33).
When CH Update flag reset command (Measured frequency value) (RY2C, RY44) is turned off then on, the high-speed counter
module turns off CH Update flag (Measured frequency value) (RX2D, RX45) and turns on CH Update flag reset completed
3)
(Measured frequency value) (RX2C, RX44). After that, CH Update flag reset completed (Measured frequency value) (RX2C,
RX44) turns off when CH Update flag reset command (Measured frequency value) (RY2C, RY44) is turned off.
CH Measured frequency value (RWr1A to RWr1B, RWr32 to RWr33) is updated even when CH Update flag (Measured
4)
frequency value) (RX2D, RX45) is on.
CH Frequency measurement flag (RWr20.b4, RWr38.b4) changes to Not operating (0) when CH Count enable command
5)
(RY24, RY3C) is turned off.
● The margin of error (maximum) of the frequency measurement function is calculated from the following formula.
Real frequency (Hz)
The following table shows each value to be put into the formula.
Ex.
Real frequency (Hz)
Time unit (Frequency measurement) (s)
Moving average count (Frequency measurement)
The margin of error (maximum) is calculated as shown below.
● CH Measured frequency value (RWr1A to RWr1B, RWr32 to RWr33) is updated without resetting CH Update flag
(Measured frequency value) (RX2D, RX45).
● CH Update flag reset command (Measured frequency value) (RY2C, RY44) responds within T
T
, refer to the following.
1
• Internal Control Cycle and Response Delay Time ( Page 305, Appendix 4)
Description
100 (ppm)
+
1000000
(Frequency measurement) (S)
Item
100 (ppm)
1234 (Hz) +
1000000
= 0.1234 (Hz) + 50 (Hz)
= 50.1234 (Hz)
1
Time unit
(Frequency measurement)
Value
1234Hz
0.01s
2 times
1
0.01 (s) 2
CHAPTER 8 FUNCTIONS
Moving average count
after the action. For
1
165
8