Mitsubishi Electric MELSEC iQ-R Series User Manual page 37

Section 3 NAME AND FUNCTION OF EACH PART
3.4.7 Waveform data output function
Waveform data is sampling data of current / voltage waveform of the measured circuit. Using this data, it is
possible to display the waveform, obtain changes of waveform. (Each data is converted value as unit V, A)
Waveform data is stored into the buffer memory in two methods as below.
* Waveform data to be measured is same, whereas buffer memory for storing data different.
(1) Waveform data sampled during period of measured data acquisition clock is stored into the buffer
memory.
The waveform data is stored into the buffer memory per period of measured data acquisition clock.
The buffer memory for storing multiple waveform data is secured. Waveform data sampled per sampling
period (254μs) during period of measured data acquisition clock is collectively stored into the buffer memory.
This method is used for acquiring waveform data synchronized with period of measured data acquisition
clock.
Refer to "4.2.1(8)" for synchronizing method.
(a) Measuring items
Measured items
waveform data of voltage
waveform data of current
(b) Number of waveform data
The number of each waveform data to be stored is the number of sampling during period of measured
data acquisition clock.
Since the sampling period is not synchronized with the period of measured data acquisition clock, the
number of waveform data may be different even in the same period of measured data acquisition clock.
Thus, the number of each waveform data is stored into the buffer memory separately from the waveform
data.
(c) Restrictions for waveform data:
・It is impossible to obtain waveform data immediately after applying power to programmable controller
system. (Module ready OFF state)
Obtain waveform data after confirming "Module ready ON state".
・It is impossible to obtain waveform data immediately after setting operating condition of this device.
Obtain waveform data after confirming "operating condition setting completed flag" is ON.
・Set the period of measured data acquisition clock below 50ms.
Where the period is larger than 50ms, waveform data is not stored into the buffer memory.
・It is possible to occur communication error inside the RE81WH due to disturbance noise (parallel noise
to CT line). When a communication error is occurred (when a communication error flag indicates error),
waveform data during the period of measured data acquisition clock is not stored into the buffer memory.
Instead "0" is stored into the buffer memory.
Details
waveform data of 1-2 line voltage
waveform data of 2-3 line voltage
waveform data of 1-phase current
waveform data of 3-phase current
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*1
RE81WH