Eaton easyE4 - Page 513

6. Function blocks
6.1 Manufacturer function blocks
Storage mode
You can select between Ring buffer and Until number of log files is reached :
l
Ring buffer
All events are stored in a specified number of files. One file after another gets
filled with the specified number of data sets. At the same time as the last file gets
filled with the last data set, the first file is already getting prepared for the next
data set and the data sets it contains get deleted. The next data set is written to
the first file as the first data set. This prevents any loss of current value data.
On the ring buffer, select the
number of files for each log session > 1.
Example of data logger as a ring buffer

((Number of files per
log session)
* (Number of data sets
per log file))
– (1 data set)) = Maximum
number of
data sets
per CSV
file
( 2 * 100 ) – 1 = 199
If for example 2 files with 100 data sets are defined for a log session, up to 199
data sets can be written and then read out again.
When the 199th data set is written, the 2nd file is closed and the first one is
opened for the next data set. This involves the values stored in it getting deleted.
This means that the 100 oldest data sets can be read out safely.
Here, the individual steps are explained:
1. A maximum of 100 data sets, data set 0 to data record 99, are entered in
00000001.LOG. Data sets 0 to 98 are then entered in 00000002.LOG.

2. Data set 99 is entered in 00000002.LOG and 00000001.LOG is prepared for the
next data set.
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easyE402/24 MN050009ENEaton.com
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