The OffNormalAlarmType is a specialization of the DiscreteAlarmType intended to represent a discrete Condition that is considered to be not normal. It is formally defined in Table 72. This sub type is usually used to indicate that a discrete value is in an Alarm state, it is active as long as a non-normal value is present.

Table 72 – OffNormalAlarmType Definition

Attribute

Value

BrowseName

OffNormalAlarmType

IsAbstract

False

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

Subtype of the DiscreteAlarmType defined in clause 5.8.17.1

HasSubtype

ObjectType

TripAlarmType

Defined in Clause 5.8.17.4

HasSubtype

ObjectType

SystemOffNormalAlarmType

Defined in Clause 5.8.17.3

HasProperty

Variable

NormalState

NodeId

PropertyType

Mandatory

The NormalState Property is a Property that points to a Variable which has a value that corresponds to one of the possible values of the Variable pointed to by the InputNode Property where the NormalState Property Variable value is the value that is considered to be the normal state of the Variable pointed to by the InputNode Property. When the value of the Variable referenced by the InputNode Property is not equal to the value of the NormalState Property the Alarm is Active. If this Variable is not in the AddressSpace, a NULL NodeId shall be provided.