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Protection
Alarms
SKF Multilog On-Line System IMx-M
2 - 25
User Manual
Figure 2 - 16.
Demonstration of Alarm Switching On and Off.
Table 2-3: Alarm switch on/off value.
Alarm
Alarm Switch On Value
Alarm Switch Off Value
Alert High
Alert high level value
Alert high level value - Alert hysteresis value
Alert Low
Alert low level value
Alert low level value + Alert hysteresis value
Danger High
Danger high level value
Danger high level value - Danger hysteresis value
Danger Low
Danger low level value
Danger low level value + Danger hysteresis value
Alarm Delayed Trigger and Release
The alarm enter and leave times are used as filters to prevent triggering alarms in a
situation where the alarm level could be exceeded for brief periods of time, because of
noise or other process specific reasons, even though there were no real alarm condition.
Enter time:
The period of time for a channel to have exceeded an alarm level
before an actual alarm condition is raised. Alert/Danger "ON" trigger will be
delayed by this Enter Time.
Leave time (only for digital channels):
The period of time which a channel in an
alarm state has to be out of its alarm operating range (alarm level adjusted with
configured
hysteresis
) before the alarm condition is canceled. Alert/Danger "OFF"
trigger will be delayed by this Leave Time.