The QosDataTypes defined in the following chapters are used in the DatagramQos parameter in different datagram specific transport protocol mapping settings.

The DatagramQos contains an array of QosDataTypes. The array is null or empty if no QoS related parameters are set.

The DatagramQos parameter is always combined with a QosCategory parameter. Depending on the content of the QosCategory String, different elements need to be present within the DatagramQos array.

The specific processing of the QosCategory and DatagramQos content is described in 5.4.5.4.

Standard QosCategory values are defined in Table 103.

Table 103 – Standard QosCategory values

QosCategory

Description

Null or empty

This category indicates best-effort is used.

DatagramQos shall be null or empty.

Opc.qos.cat://priority

This category indicates priority is used.

DatagramQos shall contain one element of TransmitQosPriorityDataType or ReceiveQosPriorityDataType and optionally further elements which may be omitted.

This Structure DataType is an abstract base type for Structures with QoS related parameters. The QosDataType is formally defined in Table 104.

Table 104 – QosDataType structure

Name

Type

Description

QosDataType

Structure

The QosDataType Structure representation in the AddressSpace is defined in Table 105.

Table 105 – QosDataType definition

Attributes

Value

BrowseName

QosDataType

IsAbstract

True

Subtype of Structure defined in OPC 10000-5.

Conformance Units

PubSub Parameters QoS

This Structure DataType is an abstract base type for Structures with transmit QoS related parameters. The TransmitQosDataType is formally defined in Table 106.

Table 106 – TransmitQosDataType structure

Name

Type

Description

TransmitQosDataType

Structure

The TransmitQosDataType Structure representation in the AddressSpace is defined in Table 107.

Table 107 – TransmitQosDataType definition

Attributes

Value

BrowseName

TransmitQosDataType

IsAbstract

True

Subtype of QosDataType defined in 6.4.1.1.2.

Conformance Units

PubSub Parameters QoS

The PriorityLabel with DataType String specifies the priority of the according sender. The network stack will use the PriorityLabel to look up the priority settings for the transport protocol headers.

The priority labels defined by OPC UA should have the following form:

opc.qos.lbl://<label>

Example values are “opc.qos.lbl://low” or “opc.qos.lbl://high”. The mapping is described in 5.4.5.4.

Note: This version does not define concrete labels. The engineering process needs to provide them and also build up the PriorityMappingTable in OPC 10000-22 accordingly.

This Structure DataType is used to represent the priority lable specific transmit QoS parameters. It is a subtype of the TransmitQosDataType defined in 6.4.1.1.3.

The TransmitQosPriorityDataType is formally defined in Table 108.

Table 108 – TransmitQosPriorityDataType structure

Name

Type

Description

TransmitQosPriorityDataType

Structure

Subtype of TransmitQosDataType defined in 6.4.1.1.3.

PriorityLabel

String

Defined in 6.4.1.1.4.1.

Its representation in the AddressSpace is defined in Table 109.

Table 109 – TransmitQosPriorityDataType definition

Attributes

Value

BrowseName

TransmitQosPriorityDataType

IsAbstract

False

Subtype of TransmitQosDataType defined in 6.4.1.1.3.

Conformance Units

PubSub Parameters QoS

This Structure DataType is an abstract base type for Structures with receive QoS related parameters. The ReceiveQosDataType is formally defined in Table 110.

Table 110 – ReceiveQosDataType structure

Name

Type

Description

ReceiveQosDataType

Structure

The ReceiveQosDataType Structure representation in the AddressSpace is defined in Table 111.

Table 111 – ReceiveQosDataType definition

Attributes

Value

BrowseName

ReceiveQosDataType

IsAbstract

True

Subtype of QosDataType defined in 6.4.1.1.2.

Conformance Units

PubSub Parameters QoS

The PriorityLabel with DataType String specifies the priority of the according sender.

Futher details are defined in 6.4.1.1.4.1.

This Structure DataType is used to represent the priority lable specific receive QoS parameters. It is a subtype of the ReceiveQosDataType defined in 6.4.1.1.5.

The ReceiveQosPriorityDataType is formally defined in Table 112.

Table 112 – TransmitQosPriorityDataType structure

Name

Type

Description

ReceiveQosPriorityDataType

Structure

Subtype of ReceiveQosDataType defined in 6.4.1.1.5.

PriorityLabel

String

Defined in 6.4.1.1.6.1.

Its representation in the AddressSpace is defined in Table 113.

Table 113 – ReceiveQosPriorityDataType definition

Attributes

Value

BrowseName

ReceiveQosPriorityDataType

IsAbstract

False

Subtype of ReceiveQosDataType defined in 6.4.1.1.5.

Conformance Units

PubSub Parameters QoS