ABB RELION REX640 Technical Manual page 1491

1MRS759142 F
In the trend mode, one value is recorded for each enabled analog channel, once per
fundamental cycle. The recorded values are RMS values, which are scaled to peak
level. The binary channels of the disturbance recorder are also recorded once per
fundamental cycle in the trend mode.
The trend mode enables recording times of 32 *
8.2.3.8 Pre-trigger and post-trigger data
The waveforms of the disturbance recorder analog channels and the states of
the disturbance recorder binary channels are constantly recorded into the history
memory of the recorder. The percentage of the data duration preceding the
triggering, that is, the pre-trigger time, can be adjusted with the
parameter. The duration of the data following the triggering, that is, the post-
trigger time, is the difference between the recording length and the pre-trigger
time. Changing the pre-trigger time resets the history data and the current
recording under collection.
8.2.3.9 Operation modes
The disturbance recorder has two operation modes: saturation and overwrite mode.
The operation mode of the disturbance recorder can be changed with the
mode parameter.
Saturation mode
In saturation mode, the captured recordings cannot be overwritten with new
recordings. Capturing the data is stopped when the recording memory is full, that
is, when the maximum number of recordings is reached. In this case, the event
is sent via the state change (TRUE) of the
memory available again, another event is generated via the state change (FALSE) of
the
Overwrite mode
In the overwrite mode, if the recording memory is full, the oldest recording is
overwritten with the pre-trigger data collected for the next recording. Each time
a recording is overwritten, the event is generated via the state change of the
Overwrite of rec. parameter.
The overwrite mode is recommended if it is important to have the latest recordings
in the memory. The saturation mode is preferred when the oldest recordings are
more important.
New triggerings are blocked in both modes until the previous recording is
completed, but a new triggering can be accepted before all pre-trigger samples
are collected for the new recording. In such a case, the recording is as much shorter
as there are pre-trigger samples lacking.
REX640
Technical Manual
Only post-trigger data is captured in trend mode.
Memory full parameter.
Measurement functions
Record length .
Memory full parameter. When there is
Pre-trg length
Operation
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