The ExclusiveLimitStateMachineType defines the state machine used by AlarmConditionTypes that 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 93 and the state transitions are described in Table 94.
Table 93 – ExclusiveLimitStateMachineType definition
|
Attribute |
Value |
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|
BrowseName |
ExclusiveLimitStateMachineType |
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|
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 Variables of the ExclusiveLimitStateMachineType have additional Attributes defined in Table 95.
Table 95 – ExclusiveLimitStateMachineType Attribute values for child Nodes
|
BrowsePath |
Value Attribute |
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|
1 |
||
|
2 |
||
|
3 |
||
|
4 |
||
|
34 |
||
|
43 |
||
|
21 |
||
|
12 |
The ExclusiveLimitStateMachineType defines the sub state machine that represents the actual level of a multilevel Alarm when it is in the Active state. The sub state machine defined here includes High, Low, HighHigh and LowLow states. 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 Active state. This Active state could be part of a “level” Alarm or “deviation” Alarm or any other Alarm state machine.
The LowLow, Low, High, HighHigh are 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 AvailableStates and/or AvailableTransitions (see 10000-16).