This VariableType is used to represent the process data input and output of an IO-Link Device. The Properties defined by this type define the length of the Variable as well as a descriptor of the structure. The ProcessVariableType is formally defined in Table 58.

Table 58 – ProcessDataVariableType Definition

Attribute	Value
BrowseName	ProcessDataVariableType
IsAbstract	False
ValueRank	1 (1 = OneDimension)
DataType	Byte
References	Node Class	BrowseName	DataType	TypeDefinition	Modelling Rule
Subtype of the BaseDataVariableType defined in OPC 10000-5.
HasProperty	Variable	ProcessDataLength	Byte	PropertyType	Mandatory
HasProperty	Variable	PDDescriptor	Byte[][3]	PropertyType	Optional

The read-only Variable ProcessDataLength is representing the structure ProcessDataIn defined in IO-Link Specification, B.1.6, and contains information about the length of the ProcessData. The value (one byte) shall directly be mapped to the Byte DataType.

The optional read-only Variable PDDescriptor is representing the structure PD Input Descriptor or PD Output Descriptor defined in IO-Link Common Profile, B.5.2 and B.5.3. The value shall be mapped to an array of an array of Bytes of length three.

NOTE: The PDDescriptor defines the structure of the ProcessData by defining the data type, length and offset in the data of potentially several data entries in the ProcessData (see IO-Link Common Profile). It is not further mapped to OPC UA information (e.g. by providing sub-variables for each entry with the concrete value based on the ProcessData) as this can potentially change dynamically and this is not recognizable in time by the OPC UA Server.