UA Part 9: Alarms and Conditions - B.1 Examples for Event sequences from Condition instances

B.1 Examples for Event sequences from Condition instances

The following examples show the Eventflow for typical Alarmsituations. The tables list the value of state Variablesfor each Event Notification.

B.1.2 Server maintains current state only

This example is for Serversthat do not support previous states and therefore do not create and maintain Branchesof a single Condition.

Figure B.1shows an Alarmas it becomes active and then inactive and also the acknowledgement and confirmation cycles. Table B.1lists the values of the state Variables. All Eventsare coming from the same Conditioninstance and therefore have the same ConditionId.

Figure B.1– Single state example

Table B.1– Example of a Condition that only keeps the latest state

EventId	BranchId	Active	Acked	Confirmed	Retain	Description
-*)	NULL	False	True	True	False	Initial state of Condition.
1	NULL	True	False	True	True	Alarmgoes active.
2	NULL	True	True	False	True	Conditionacknowledged Confirm required
3	NULL	False	True	False	True	Alarmgoes inactive.
4	NULL	False	True	True	False	Conditionconfirmed
5	NULL	True	False	True	True	Alarmgoes active.
6	NULL	False	False	True	True	Alarmgoes inactive.
7	NULL	False	True	False	True	Conditionacknowledged, Confirm required.
8	NULL	False	True	True	False	Conditionconfirmed.
) The first row is included to illustrate the initial state of the Condition. This state will not be reported by an Event*.

B.1.3 Server maintains previous states

This example is for Serversthat are able to maintain previous states of a Conditionand therefore create and maintain Branchesof a single Condition.

Figure B.2illustrates the use of branches by a Serverrequiring acknowledgement of all transitions into Activestate, not just the most recent transition. In this example no acknowledgement is required on a transition into an inactive state. Table B.2lists the values of the state Variables. All Eventsare coming from the same Conditioninstance and have therefore the same ConditionId.

Figure B.2– Previous state example

Table B.2– Example of a Conditionthat maintains previous states via branches

EventId	BranchId	Active	Acked	Confirmed	Retain	Description
a)	NULL	False	True	True	False	Initial state of Condition.
1	NULL	True	False	True	True	Alarm goes active.
2	NULL	True	True	True	True	Condition acknowledged requires Confirm
3	NULL	False	True	False	True	Alarmgoes inactive.
4	NULL	False	True	True	False	Confirmed
5	NULL	True	False	True	True	Alarmgoes active.
6	NULL	False	True	True	True	Alarmgoes inactive.
7	1	True	False	True	True b)	Prior state needs acknowledgment. Branch #1 created.
8	NULL	True	False	True	True	Alarmgoes active again.
9	1	True	True	False	True	Prior state acknowledged, Confirm required.
10	NULL	False	True	True	True b)	Alarmgoes inactive again.
11	2	True	False	True	True	Prior state needs acknowledgment. Branch #2 created.
12	1	True	True	True	False	Prior state confirmed. Branch #1 deleted.
13	2	True	True	True	False	Prior state acknowledged, Auto Confirmed by system Branch #2 deleted.
14	NULL	False	True	True	False	No longer of interest.
a)The first rowis included to illustrate the initial state of the Condition. This state will not be reported by an Event. Notes on specific situations shown with this example: If the current state of the Conditionis acknowledged then the Ackedflag is set and the new state is reported (Event#2). If the Conditionstate changes before it can be acknowledged (Event#6) then a branch state is reported (Event#7). Timestamps for the Events #6 and #7 is identical. The branch state can be updated several times (Events #9) before it is cleared (Event#12). A single Conditioncan have many branch states active (Events #11) b)It is recommendedas in this table to leave Retain=True as long as there exist previous states (branches).