Any state
State G
shelved
Shelve
period
expired?
No
Yes
Operator action
Automatic action
Unshelve
alarm
Unshelve
alarm
Shelve
alarm
for a period
State A
Operator shelves the alarm.
Operator unshelves the alarm.
Check whether the shelve
period has expired.
The controller automatically
unshelves the alarm after the
period expires.
4.4.4 Out of service
You can take any alarm
Out of service
, during any alarm state (except if the alarm is already
Shelved
). When an alarm is
Out of
service
, the alarm is suspended indefinitely.
DANGER!
Taking certain alarms
Out of service
can disable critical protections. In addition, taking
Out of service
automatically
acknowledges the alarm and resets the latch.
Any state
State I
Out of service
Operator action
Take
Out of service
Return to
service
State A
Operator removes the alarm from service.
Alarm is out of service and not active.
Operator returns the alarm to service.
DESIGNER'S HANDBOOK 4189340911K UK
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