AccuEnergy Acuvim II series - Page 290

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Records" field from the last reading before retrieving the information and
reading the window.
If the current "Used Records" eld is greater than the "Used Records" eld from
the last reading and if the "Oset" eld is less than the dierence between the
current and previous "Used Records" eld, the rst sector has been erased and
the dierence between the "Used Records" eld should be subtracted from the
recording number.
If the "Offset" field is greater than the difference between the current and
previous "Used Records" eld, the "Oset" number should be subtracted from
the recording number.
To avoid this situation, user should read the log before it is almost full.
For example: Data logging 1 has 3 sectors and each has 448 records, and
the total records are 1344. If you press the "Read All" button when the
"Used Records" number is at 1340 and if the first sector is erased before the
information is transferred to the computer, the data stored in this sector is
erased permanently and cannot be retrieved. If the records from the rst sector
can be retrieved before it gets erased, the new value of "Oset" will equal to the
original "Oset" eld minus the value of the dierence between the current and
previous "Used Records" eld.
Data logging opration examples
The following example illustrates a data logging opertation. The example makes
the following assumptions:
• The log is Historical Log 1.
• The log contains VAN, VBN, VCN (12 bytes),the interval is 1min, the sectors is
10,the registers is 6, the logging timer function is disabled.
• Retrieval is starting at record oset 0 (oldest record).