Mitsubishi Electric MELSEC iQ-R Series User Manual page 44

Section 4 I/O SIGNALS TO CPU MODULE
(8) Measured data acquisition clock (Xn8)
The clock is to acquire measured data by synchronizing with this module.
If it is able to detect switching from ON to OFF (or OFF to ON) of the signal (Xn8), it is possible to obtain
measured data in synchronization with this module.
(a) Clock operation
After the power is supplied to the CPU module and immediately after the initial computation is performed,
this signal (Xn8) is turned ON and clock operation is started. After that, this signal turns ON at the timing
when the measurement data is completely written into the buffer memory after the elapse of the period of
measured data acquisition clock.
If the settings of the phase wire system, primary voltage, primary current, primary voltage of VT, secondary
voltage of VT, primary current of CT and period of measured data acquisition clock are changed, this
signal turns ON immediately after the change of the settings and clock operation is started.
Below diagram indicates ON time and OFF time of this signal (Xn8).
Period of
measured data
acquisition clock
10ms
20 to 10000ms
T
6 to 10ms
4/5 to 1 of the period
of measured data
acquisition clock
T
ON
4ms
2/5 of the measured
data acquisition clock
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RE81WH
T
OFF
2 to 6ms
2/5 to 3/5 of the period
of measured data
acquisition clock