Manual MRI3 GB
Woodward
DOK-TD-MRI3 Rev.A
11
3.2.1 Fault
recorder
The MRI3 is equipped with a disturbance value recorder which records the measured analogue
values as momentary values. The momentary values
iL1, iL2, iL3, i
E
,
are scanned within a grid 1.25 ms (with 50 Hz) or 1.041 ms (with 60 Hz) and filed in a circulating
storage. The max. storage capacity amounts to 16 s (with 50 Hz) or 13.33 s (with 60 Hz).
Storage division
Independent of the recording time, the entire storage capacity can be divided into several cases of
disturbance with a shorter recording time each. In addition, the deletion behaviour of the fault re-
corder can be influenced.
No writing over
If 2, 4 or 8 recordings are chosen, the complete memory is divided into the relevant number of par-
tial segments. If this max. number of fault event has been exceeded, the fault recorder block any
further recordings in order to prevent that the stored data are written over. After the data have been
read and deleted, the recorder to ready again for further action.
Writing over
If 1, 3 or 7 recordings are chosen, the relevant number of partial segments is reserved in the com-
plete memory. If the memory is full, a new recording will always write over the oldest one.
The memory part of the fault recorder is designed as circulating storage. In this example 7 fault
records can be stored (written over).
Memory space 6 to 4 is occupied.
Memory space 5 is currently being written in
Figure 3.7: Division of the memory into 8 segments, for example
Since memory spaces 6, 7 and 8 are occupied, this example shows that the memory has been as-
signed more than eight recordings. This means that No. 6 is the oldest fault recording and No. 4
the most recent one.