Hitachi Relion 650 Series Technical Manual page 238

Section 12
Monitoring
IEC12000036 V1 EN-US
Figure 110: Operation log system overview
• This function saves records of input values to a persistent memory (flash) based on a trigger.
The connected input values can be calculated data from different functions or measured process
data.
• The records that are logged by the operation log component can be viewed in LHMI and WHMI
as common data or phase segregated data. If the signal connected has an associated unit, it will
also be displayed.
• The memory supervision component MONMEMSUP monitors the overall memory consumed by
all operation log components instantiated in the IED. Even though there is a provision for setting
maximum records for every instance of operation log, it is the memory supervision which finally
checks the IED capacity. If the size of the database exceeds the available memory of 40MB, the
newest record will overwrite the oldest one. One record created by one instance of OPLOG will
consume approximately 80 Byte of data, irrespective of the number of input channels connected
to that component.
• By a specific triggering option, a stored operation record can be marked as "fingerprint record".
Fingerprint records are retained during normal clearing of the operation log database, neither
will they be overwritten in case of memory overrun. The number of fingerprint records is limited
to 50 (settable); storing another fingerprint record after reaching this limit will overwrite the oldest
fingerprint record.
Triggering
Storing of an operation record is triggered by the input signal TRIG_IN going high. TRIG_IN is
primarily a binary signal. Depending on the application, it may be augmented by additional data to
form a composite signal.
If the application is to store operation data of the circuit breaker along with the time stamp and
operation type, a composite trigger signal should be applied comprising the following information.
• Time stamp provided by the application, for example, the time when a command has been
received
• Circuit breaker operation type (Close or Open)
• Whether the data should be stored as fingerprint record
232
Trigger memory
Supervision to
generate an event
Storing operation log
data
A mechanism for limiting the number of write operations per time period is
implemented in the IED, to prevent the flash memory from wearing out. As a
consequence, it may take up an hour to save new operation records permanently in
the database. If the auxiliary power is interrupted before new data are saved, these
data are lost. The time of flash saving is neither indicated on the IED nor can it be
influenced by the user.
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Memory
Supervision
Overall Oplog
MaxRec
Read
operation log
data
WHMI
Operation log
database
1MRK 511 557-UEN Rev. A
IEC12000036-1-en.vsd
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Technical Manual