Data Sheet 71M6531D/F-71M6532D/F
FDS 6531/6532 005
833ms
20ms
XFER_BUSY
Interrupt to MPU
Figure 7: Accumulation Interval
shows the accumulation interval resulting from
PRE_SAMPS
= 42 and
SUM_CYCLES
= 50, con-
sisting of 2100 samples of 397µs each, followed by the XFER_BUSY interrupt. The sampling in this ex-
ample is applied to a 50 Hz signal.
There is no correlation between the line signal frequency and the choice of
PRE_SAMPS
or
SUM_CYCLES
(even
though when
SUM_CYCLES
= 42 one set of
SUM_CYCLES
happens to sample a period of 16.6 ms).
Furthermore, sampling does not have to start when the line voltage crosses the zero line and the length
of the accumulation interval need not be an integer multiple of the signal cycles.
18
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