Pre-Trigger And Post-Trigger Data - ABB RELION REX640 Technical Manual

1MRS759142 C
8.2.3.8
8.2.3.9
REX640
Technical Manual
mode manual parameter for manual trigger and the Stor. mode periodic parameter for
periodic trigger.
In the waveform mode, the samples are captured according to the Storage rate and
Pre-trg length parameters.
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.
Only post-trigger data is captured in trend mode.
The trend mode enables recording times of 32 ⋅ Record length.

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 Pre-trg length 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.
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 Operation
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 full parameter. When there is memory
available again, another event is generated via the state change (FALSE) of the
Memory full parameter.
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.
Section 8
Measurement functions
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