Errata exists for this version of the document.

This VariableType defines the general characteristics of a DiscreteItem that can have more than two states. The MultiStateDiscreteType derives from the DiscreteItemType. It is formally defined in Table 5.

Table 5 – MultiStateDiscreteType definition

Attribute	Value
BrowseName	MultiStateDiscreteType
IsAbstract	False
ValueRank	−2 (−2 = ‘Any’)
DataType	UInteger
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	EnumStrings	LocalizedText[]	PropertyType	Mandatory

EnumStrings is a string lookup table corresponding to sequential numeric values (0, 1, 2, etc.)

Example:

”OPEN”

”CLOSE”

”IN TRANSIT” etc.

Here the string “OPEN” corresponds to 0, “CLOSE” to 1 and “IN TRANSIT” to 2.

Clients should be prepared to handle item values outside of the range of the list; and robust servers should be prepared to handle writes of illegal values.

If the item contains an array then this lookup table shall apply to all elements in the array.

NOTE The EnumStrings property is also used for Enumeration DataTypes (for the specification of this DataType, see OPC 10000-3).

The StatusCode SemanticsChanged bit shall be set if the EnumStrings ( changes can cause misinterpretation by users or (scripting) programs) Property is changed (see section 5.2 for additional information).