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This VariableType defines the general characteristics of a DiscreteItem that can have more than two states and where the state values (the enumeration) does not consist of consecutive numeric values (may have gaps) or where the enumeration is not zero-based. The MultiStateValueDiscreteType derives from the DiscreteItemType. It is formally defined in Table 6.

Table 6 – MultiStateValueDiscreteType definition

Attribute	Value
BrowseName	MultiStateValueDiscreteType
IsAbstract	False
ValueRank	Scalar
DataType	Number
References	NodeClass	BrowseName	DataType TypeDefinition	ModellingRule
Subtype of the DiscreteItemType defined in 5.3.3; i.e the Properties of that type are inherited.
HasProperty	Variable	EnumValues	See OPC 10000-3	Mandatory
HasProperty	Variable	ValueAsText	See OPC 10000-3	Mandatory

EnumValues is an array of EnumValueType. Each entry of the array represents one enumeration value with its integer notation, a human-readable representation, and help information. This represents enumerations with integers that are not zero-based or have gaps (e.g. 1, 2, 4, 8, 16). See OPC 10000-3 for the definition of this type. MultiStateValueDiscrete Variables expose the current integer notation in their Value Attribute. Clients will often read the EnumValues Property in advance and cache it to lookup a name or help whenever they receive the numeric representation.

MultiStateValueDiscrete Variables can have any numeric Data Type; this includes signed and unsigned integers from 8 to 64 Bit length.

The numeric representation of the current enumeration value is provided via the Value Attribute of the MultiStateValueDiscrete Variable. The ValueAsText Property provides the localized text representation of the enumeration value. It can be used by Clients only interested in displaying the text to subscribe to the Property instead of the Value Attribute.