This clause describes the state machine and the base AlarmType behaviour for AlarmConditionTypeswith multiple mutually exclusive limits.
The ExclusiveLimitStateMachineTypedefines the state machine used by AlarmConditionTypesthat handle multiple mutually exclusive limits. It is illustrated in Figure 19.
Figure 19– ExclusiveLimitStateMachineType
It is created by extending the FiniteStateMachineType. It is formally defined in Table 93and the state transitions are described in Table 94.
Table 93– ExclusiveLimitStateMachineType definition
Attribute |
Value |
||||
BrowseName |
ExclusiveLimitStateMachineType |
||||
IsAbstract |
False |
||||
References |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
ModellingRule |
Subtype of the FiniteStateMachineType |
|||||
HasComponent |
Object |
HighHigh |
|
StateType |
|
HasComponent |
Object |
High |
|
StateType |
|
HasComponent |
Object |
Low |
|
StateType |
|
HasComponent |
Object |
LowLow |
|
StateType |
|
HasComponent |
Object |
LowToLowLow |
|
TransitionType |
|
HasComponent |
Object |
LowLowToLow |
|
TransitionType |
|
HasComponent |
Object |
HighToHighHigh |
|
TransitionType |
|
HasComponent |
Object |
HighHighToHigh |
|
TransitionType |
|
ConformanceUnits |
|||||
A & C Exclusive Limit |
Table 94– ExclusiveLimitStateMachineType Additional References
SourceBrowsePath |
References |
IsForward |
TargetBrowsePath |
HighHighToHigh |
FromState |
True |
HighHigh |
ToState |
True |
High |
HasEffect |
True |
AlarmConditionType |
HighToHighHigh |
FromState |
True |
High |
ToState |
True |
HighHigh |
HasEffect |
True |
AlarmConditionType |
LowLowToLow |
FromState |
True |
LowLow |
ToState |
True |
Low |
HasEffect |
True |
AlarmConditionType |
LowToLowLow |
FromState |
True |
Low |
ToState |
True |
LowLow |
HasEffect |
True |
AlarmConditionType |
‘
The component Variablesof the ExclusiveLimitStateMachineTypehave additional Attributesdefined in Table 95.
Table 95– ExclusiveLimitStateMachineType Attribute values for child Nodes
BrowsePath |
Value Attribute |
||
|
1 |
||
|
2 |
||
|
3 |
||
|
4 |
||
|
34 |
||
|
43 |
||
|
21 |
||
|
12 |
The ExclusiveLimitStateMachineTypedefines the sub state machine that represents the actual level of a multilevel Alarm when it is in the Activestate. The sub state machine defined here includes High, Low, HighHighand LowLowstates. This model also includes in its transition state a series of transition to and from a parent state, the inactive state. This state machine as it is defined shall be used as a sub state machine for a state machine which has an Activestate. This Activestate could be part of a “level” Alarmor “deviation” Alarmor any other Alarmstate machine.
The LowLow, Low, High, HighHighare typical for many industries. Vendors can introduce sub-state models that include additional limits; they may also omit limits in an instance. If a model omits states or transitions in the StateMachine, it is recommended that they provide the optional Property AvailableStatesand/or AvailableTransitions(see 10000-16).
The ExclusiveLimitAlarmTypeis used to specify the common behaviour for Alarm Typeswith multiple mutually exclusive limits. The ExclusiveLimitAlarmTypeis illustrated in Figure 20.
Figure 20– ExclusiveLimitAlarmType
The ExclusiveLimitAlarmTypeis formally defined in Table 96.
Table 96– ExclusiveLimitAlarmType definition
Attribute |
Value |
||||
BrowseName |
ExclusiveLimitAlarmType |
||||
IsAbstract |
False |
||||
References |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
ModellingRule |
Subtype of the LimitAlarmType defined in clause 5.8.18. |
|||||
HasSubtype |
ObjectType |
ExclusiveLevelAlarmType |
Defined in Clause 5.8.21.3 |
||
HasSubtype |
ObjectType |
ExclusiveDeviationAlarmType |
Defined in Clause 5.8.22.3 |
||
HasSubtype |
ObjectType |
ExclusiveRateOfChangeAlarmType |
Defined in Clause 5.8.23.3 |
||
HasComponent |
Object |
LimitState |
|
Mandatory |
|
ConformanceUnits |
|||||
A & C Exclusive Limit |
The LimitStateis a sub state of the ActiveState and has an IsTrueSubStateOfreference to the ActiveState. The LimitStaterepresents the actual limit that is violated in an instance of ExclusiveLimitAlarmType. When the ActiveStateof the AlarmConditionTypeis inactive the LimitStateshall not be available and shall return NULL on read. Any Eventsthat subscribe for fields from the LimitStatewhen the ActiveStateis inactive shall return a NULL for these unavailable fields.