B.1.4 Server current-State Model with Suppression

This example adds additional fields to the model illustrated in B.1.2. This example does not use acknowledge or confirm – it assumes that the alarm is automatically acknowledged (and does not support confirm). It does add OutOfServiceState and SuppressedState.

Figure B.3 shows an Alarm as it becomes active, is suppressed or is placed out of service and then inactive. Table B.3 lists the values of the state Variables. All Events are coming from the same Condition instance and therefore have the same ConditionId. The Client subscription includes an event filter that excludes suppressed or out of service conditions (i.e. SuppressedState = True or OutOfServiceState = True). The events shown in green are delivered to the Client. The Retain column indicates the global value of the Retain flag. The “Retain sent” column indicates the overridden value sent in a notification if SupportsFilteredRetain is True. If SupportsFilteredRetain is False the value from the Retain column is sent.

image038.png

Figure B.3 – SuppressedState and OutOfServiceState example

Table B.3 – Example of a Condition that is Suppressed / OutOfService

EventId

Active

Suppressed

State

OutOf

Service

State

Retain

Retain sent

Event Deliver with Filter

Description

-*)

False

False

False

False

False

-

Initial state of Condition.

1

True

False

False

True

True

Yes

Alarm goes active.

2

True

False

True

True

False

Yes

Placed OutOfService

3

True

True

True

True

False

No

Alarm Suppressed; No event since OutOfService

4

False

True

True

False

False

No

Alarm goes inactive; No event since OutOfService

5

False

False

True

False

False

No

Alarm not Suppressed; No event since not active

6

True

False

True

True

False

No

Alarm goes active; No event since OutOfService

7

True

False

False

True

True

Yes

Alarm no longer OutOfService; Event generated

8

False

False

False

False

False

Yes

Alarm goes inactive

9

False

True

False

False

False

No

Alarm Suppressed; No event since not active

10

True

True

False

True

False

No

Alarm goes active; No event since Suppressed

11

False

True

False

False

False

No

Alarm goes inactive; No event since Suppressed

12

False

False

False

False

False

No

Alarm no longer Suppressed

13

False

False

True

False

False

No

Placed OutOfService

14

True

False

True

True

False

No

Alarm goes active; No event since OutOfService

15

False

False

True

False

False

No

Alarm goes inactive; No event since OutOfService

16

False

False

False

False

False

No

Alarm no longer OutOfService

This behaviour occurs when the implementation supports SupportsFilteredRetain flag subscription.