ABB RELION 620 Series Technical Manual page 784

Section 10
Recording functions
10.1.1.9
10.1.1.10
778
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 Pre-trg 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.
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 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
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 Overwrite
of rec. parameter. The overwrite mode is recommended, 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.
Exclusion mode
Exclusion mode is on, when the value set with the Exclusion time parameter is higher than
zero. During the exclusion mode, new triggerings are ignored if the triggering reason is the
same as in the previous recording. The Exclusion time parameter controls how long the
exclusion of triggerings of same type is active after a triggering. The exclusion mode only
applies to the analog and binary channel triggerings, not to periodic and manual
triggerings.
When the value set with the Exclusion time parameter is zero, the exclusion mode is
disabled and there are no restrictions on the triggering types of the successive recordings.
1MAC504801-IB E
620 series ANSI
Technical Manual