ABB RELION SMU615 Technical Manual page 222

Measurement functions
In the waveform mode, the samples are captured according to the
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.
The trend mode enables recording times of 32 *
7.2.2.8 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 user can adjust the percentage of the data duration
preceding the triggering, that is, the so-called pre-trigger time, with the
length parameter. The duration of the data following the triggering, that is, the
so-called 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.
7.2.2.9 Operation modes
Disturbance recorder has two operation modes: saturation and overwrite mode. The
user can change the operation mode of the disturbance recorder 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
When the operation mode is "Overwrite" and 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
if it is more 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 the saturation and the overwrite mode until
the previous recording is completed. On the other hand, 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 were pre-trigger samples lacking.
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Only post-trigger data is captured in trend mode.
Memory full parameter.
Overwrite of rec. parameter. The overwrite mode is recommended,
Record length .
Memory full parameter. When there is
1MRS758407 C
Storage rate and
Pre-trg
Operation
SMU615
Technical Manual