6 PubSub communication parameters ToC Previous Next

6.4 Transport Protocol mapping configuration parameters ToC Previous Next

6.4.1 Datagram Transport Protocol ToC Previous Next

6.4.1.1 Quality of service parameters ToC

6.4.1.1.1 QosCategory and DatagramQos ToC

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 102.

Table 102 – 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.

6.4.1.1.2 QosDataType structure ToC Model

This Structure DataType is an abstract base type for Structures with QoS related parameters. The QosDataType is formally defined in Table 103.

Table 103 – QosDataType structure

Name Type Description
QosDataType Structure  

The QosDataType Structure representation in the AddressSpace is defined in Table 104.

Table 104 – QosDataType definition

Attributes Value      
BrowseName QosDataType      
IsAbstract True      
References NodeClass BrowseName IsAbstract Description
Subtype of Structure defined in OPC 10000-5.        
HasSubtype DataType TransmitQosDataType TRUE Defined in 6.4.1.1.3.
HasSubtype DataType ReceiveQosDataType TRUE Defined in 6.4.1.1.5.
Conformance Units        
PubSub Parameters QoS        

6.4.1.1.3 TransmitQosDataType ToC Model

This Structure DataType is an abstract base type for Structures with transmit QoS related parameters. The TransmitQosDataType is formally defined in Table 105.

Table 105 – TransmitQosDataType structure

Name Type Description
TransmitQosDataType Structure  

The TransmitQosDataType Structure representation in the AddressSpace is defined in Table 106.

Table 106 – TransmitQosDataType definition

Attributes Value      
BrowseName TransmitQosDataType      
IsAbstract True      
References NodeClass BrowseName IsAbstract Description
Subtype of QosDataType defined in 0.        
HasSubtype DataType TransmitQosPriorityDataType FALSE Defined in 6.4.1.1.4.
Conformance Units        
PubSub Parameters QoS        

6.4.1.1.4 TransmitQosPriorityDataType ToC Model

6.4.1.1.4.1 PriorityLabel ToC Model

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.

6.4.1.1.4.2 TransmitQosPriorityDataType structure ToC Model

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 107.

Table 107 – 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 108.

Table 108 – TransmitQosPriorityDataType definition

Attributes Value
BrowseName TransmitQosPriorityDataType
IsAbstract False
Subtype of TransmitQosDataType defined in 6.4.1.1.3.  
Conformance Units  
PubSub Parameters QoS  

6.4.1.1.5 ReceiveQosDataType ToC Model

This Structure DataType is an abstract base type for Structures with receive QoS related parameters. The ReceiveQosDataType is formally defined in Table 109.

Table 109 – ReceiveQosDataType structure

Name Type Description
ReceiveQosDataType Structure  

The ReceiveQosDataType Structure representation in the AddressSpace is defined in Table 110.

Table 110 – ReceiveQosDataType definition

Attributes Value      
BrowseName ReceiveQosDataType      
IsAbstract True      
References NodeClass BrowseName IsAbstract Description
Subtype of QosDataType defined in 0.        
HasSubtype DataType ReceiveQosPriorityDataType FALSE Defined in 6.4.1.1.6.
Conformance Units        
PubSub Parameters QoS        

6.4.1.1.6 ReceiveQosPriorityDataType ToC Model

6.4.1.1.6.1 PriorityLabel ToC Model

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

Futher details are defined in 6.4.1.1.4.1.

6.4.1.1.6.2 ReceiveQosPriorityDataType structure ToC Model

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 111.

Table 111 – 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 112.

Table 112 – ReceiveQosPriorityDataType definition

Attributes Value
BrowseName ReceiveQosPriorityDataType
IsAbstract False
Subtype of ReceiveQosDataType defined in 6.4.1.1.5.  
Conformance Units  
PubSub Parameters QoS  

6.4.1.2 Datagram PubSubConnection ToC Model

6.4.1.2.1 DiscoveryAddress ToC Model

The DiscoveryAddress parameter contains the network address information used for the discovery probe and announcement messages. The different Structure DataTypes used to represent the Address are defined in 6.2.7.5.3.

6.4.1.2.2 DatagramConnectionTransportDataType structure ToC Model

This Structure DataType is used to represent the datagram specific transport mapping parameters for PubSubConnections. It is a subtype of the ConnectionTransportDataType defined in 6.2.7.5.2.

The DatagramConnectionTransportDataType is formally defined in Table 113.

Table 113 – DatagramConnectionTransportDataType structure

Name Type Description
DatagramConnectionTransportDataType Structure Subtype of ConnectionTransportDataType defined in 6.2.6.4.
   discoveryAddress NetworkAddressDataType    Defined in 6.4.1.2.1. The NetworkAddressDataType is defined in 6.2.7.5.3.

Its representation in the AddressSpace is defined in Table 114.

Table 114 – DatagramConnectionTransportDataType definition

Attributes Value
BrowseName DatagramConnectionTransportDataType
IsAbstract False
Subtype of ConnectionTransportDataType defined in 6.2.7.5.2.  
Conformance Units  
PubSub Parameters Datagram  

6.4.1.2.3 DiscoveryAnnounceRate ToC Model

The DiscoveryAnnounceRate with DataType UInt32 defines the interval in seconds used for cyclic sending of discovery anouncement messages related to this connection.

The default value is 0 and defines that discovery announcement messages are only sent as response to discovery probe messages.

6.4.1.2.4 DiscoveryMaxMessageSize ToC Model

The DiscoveryMaxMessageSize with DataType UInt32 indicates the maximum size in bytes for NetworkMessages created for discovery. It refers to the size of the complete NetworkMessage including padding and signature without any additional headers added by the transport protocol mapping. If the size of a NetworkMessage exceeds the DiscoveryMaxMessageSize, the behaviour depends on the message mapping.

The default value is 0 and defines that the default size for the transport protocol ist used. The default size is defined for the transport protocol mappings in 7.3.

NOTE The value for the DiscoveryMaxMessageSize should be configured in a way that ensures that NetworkMessages together with additional headers added by the transport protocol are still smaller than or equal than the transport protocol MTU.

6.4.1.2.5 QosCategory ToC Model

Selects the general category of QoS the PubSubConnection requires. Further details are defined in 6.4.1.1.1.

The parameter shall be null or empty if no QoS related parameters are set.

6.4.1.2.6 DatagramQos ToC Model

The DatagramQos parameter contains QoS related parameters for the PubSubConnection as array of QosDataType Structures. The abstract DataType is defined in 0. The concrete subtypes are used to represent different QoS settings for transmit and receive that can be combined in the array.

The parameter shall be null or empty if no QoS related parameters are set.

6.4.1.2.7 DatagramConnectionTransport2DataType structure ToC Model

This Structure DataType is used to represent the datagram specific transport mapping parameters for a PubSubConnection.

It is a subtype of the DatagramConnectionTransportDataType defined in 6.4.1.2.2.

The DatagramConnectionTransport2DataType is formally defined in Table 115.

Table 115 – DatagramConnectionTransport2DataType structure

Name Type Description
DatagramConnectionTransport2DataType Structure Subtype of ConnectionTransportDataType defined in 6.2.6.4.
   discoveryAnnounceRate UInt32 Defined in 6.4.1.2.3.
   discoveryMaxMessageSize UInt32 Defined in 6.4.1.2.4.
   qosCategory String Defined in 6.4.1.2.5.
   datagramQos QosDataType[] Defined in 6.4.1.2.6.

Its representation in the AddressSpace is defined in Table 116.

Table 116 – DatagramConnectionTransport2DataType definition

Attributes Value
BrowseName DatagramConnectionTransport2DataType
IsAbstract False
Subtype of DatagramConnectionTransportDataType defined in 6.4.1.2.2.  
Conformance Units  
PubSub Parameters Datagram  

6.4.1.3 Datagram WriterGroup ToC Model

6.4.1.3.1 MessageRepeatCount ToC Model

The MessageRepeatCount with DataType Byte defines how many times every NetworkMessage is repeated. The default value is 0 and disables the repeating.

6.4.1.3.2 MessageRepeatDelay ToC Model

The MessageRepeatDelay with DataType Duration defines the time between NetworkMessage repeats in milliseconds. The parameter shall be ignored if the parameter MessageRepeatCount is set to 0.

6.4.1.3.3 DatagramWriterGroupTransportDataType structure ToC Model

This Structure DataType is used to represent the datagram specific transport mapping parameters for WriterGroups. It is a subtype of the WriterGroupTransportDataType defined in 6.2.6.7.2.

The DatagramWriterGroupTransportDataType is formally defined in Table 117.

Table 117 – DatagramWriterGroupTransportDataType structure

Name Type Description
DatagramWriterGroupTransportDataType Structure Subtype of WriterGroupTransportDataType defined in 6.2.6.7.2.
   messageRepeatCount Byte Defined in 6.4.1.3.1.
   messageRepeatDelay Duration Defined in 6.4.1.3.2.

Its representation in the AddressSpace is defined in Table 118.

Table 118 – DatagramWriterGroupTransportDataType definition

Attributes Value
BrowseName DatagramWriterGroupTransportDataType
IsAbstract False
Subtype of WriterGroupTransportDataType defined in 6.2.6.7.2.  
Conformance Units  
PubSub Parameters Datagram  

6.4.1.3.4 Address ToC Model

The Address parameter contains the network address information for the communication middleware related to the WriterGroup. The different Structure DataTypes used to represent the Address are defined in 6.2.7.5.3.

The parameter shall be null if an address is not set at this level. If the parameter is set, it overwrites the Address on the PubSubConnection.

6.4.1.3.5 QosCategory ToC Model

Selects the general category of QoS the WriterGroup requires. Further details are defined in 6.4.1.1.1.

The parameter shall be null or empty if no QoS related parameters are set.

6.4.1.3.6 DatagramQos ToC Model

The DatagramQos parameter contains QoS related parameters for the WriterGroup as array of TransmitQosDataType Structures. The abstract TransmitQosDataType is defined in 6.4.1.1.3. The concrete subtypes are used to represent different QoS settings that can be combined in the array.

The parameter shall be null or empty if no QoS related parameters are set.

6.4.1.3.7 DiscoveryAnnounceRate ToC Model

The DiscoveryAnnounceRate with DataType UInt32 defines the interval in seconds used for cyclic sending of discovery anouncement messages related to the WriterGroup.

The default value is 0 and defines that discovery announcement messages are only sent as response to discovery probe messages.

6.4.1.3.8 Topic ToC Model

The Topic parameter with DataType String contains the unique name of the data stream produced by the WriterGroup within a Message Oriented Middleware.

A unique default name can be created by combining the PublisherId with the WriterGroupId using ‘.’ as separator.

6.4.1.3.9 DatagramWriterGroupTransport2DataType structure ToC Model

This Structure DataType is used to represent the datagram specific transport mapping parameters for WriterGroups. It is a subtype of the DatagramWriterGroupTransportDataType defined in 6.4.1.3.3.

The DatagramWriterGroupTransportDataType is formally defined in Table 119.

Table 119 – DatagramWriterGroupTransport2DataType structure

Name Type Description
DatagramWriterGroupTransport2DataType Structure Subtype of DatagramWriterGroupTransportDataType defined in 6.4.1.3.3.
   address NetworkAddressDataType Defined in 6.4.1.3.4.
   qosCategory String Defined in 6.4.1.3.5.
   datagramQos TransmitQosDataType[] Defined in 6.4.1.3.6.
   discoveryAnnounceRate UInt32 Defined in 6.4.1.3.7.
   topic String Defined in 6.4.1.3.8.

Its representation in the AddressSpace is defined in Table 120.

Table 120 – DatagramWriterGroupTransport2DataType definition

Attributes Value
BrowseName DatagramWriterGroupTransport2DataType
IsAbstract False
Subtype of DatagramWriterGroupTransportDataType defined in 6.4.1.3.3.  
Conformance Units  
PubSub Parameters Datagram  

6.4.1.4 Datagram ReaderGroup parameters ToC

There are no datagram-specific transport mapping parameters defined for the ReaderGroup.

6.4.1.5 Datagram DataSetWriter parameters ToC

There are no datagram-specific transport mapping parameters defined for the DataSetWriter.

6.4.1.6 Datagram DataSetReader ToC Model

6.4.1.6.1 Address ToC Model

The Address parameter contains the network address information for the communication middleware related to the DataSetReader. The different Structure DataTypes used to represent the Address are defined in 6.2.7.5.3.

The parameter shall be null if an address is not set at this level. If the parameter is set, it overwrites the Address on the PubSubConnection.

6.4.1.6.2 QosCategory ToC Model

Selects the general categorty of QoS the DataSetReader requires. Further details are defined in 6.4.1.1.1.

The parameter shall be null or empty if no QoS related parameters are set.

6.4.1.6.3 DatagramQos ToC Model

The DatagramQos parameter contains the QoS related parameters for the DataSetReader as array of ReceiveQosDataType Structures. The abstract ReceiveQosDataType is defined in 6.4.1.1.5. The concrete subtypes are used to represent different QoS settings that can be combined in the array.

The parameter shall be null or empty if no QoS related parameters are set.

6.4.1.6.4 Topic ToC Model

The Topic parameter with DataType String contains the unique name of the data stream from the Publisher that contains the DataSetMessages of interest for the DataSetReader. The Topic is defined by the Publisher.

6.4.1.6.5 DatagramDataSetReaderTransportDataType structure ToC Model

This Structure DataType is used to represent the datagram transport mapping parameters for DataSetReaders. It is a subtype of the DataSetReaderTransportDataType defined in 6.2.9.13.2.

The DatagramDataSetReaderTransportDataType is formally defined in Table 121.

Table 121 – DatagramDataSetReaderTransportDataType structure

Name Type Description
DatagramDataSetReaderTransportDataType Structure Subtype of DataSetWriterTransportDataType defined in 6.2.4.5.2.
   address NetworkAddressDataType Defined in 6.4.1.6.1.
   qosCategory String Defined in 6.4.1.6.2.
   datagramQos ReceiveQosDataType[] Defined in 6.4.1.6.3.
   topic String Defined in 6.4.1.6.4.

Its representation in the AddressSpace is defined in Table 122.

Table 122 – DatagramDataSetReaderTransportDataType definition

Attributes Value
BrowseName DatagramDataSetReaderTransportDataType
IsAbstract False
Subtype of DataSetReaderTransportDataType defined in 6.2.9.13.2.  
Conformance Units  
PubSub Parameters Datagram  

Previous Next