6 PubSub Communication Parameters ToC Previous Next

6.2 Common Configuration Parameters ToC Previous Next

6.2.5 WriterGroup Parameters ToC Previous Next

6.2.5.1 WriterGroupId ToC

The WriterGroupId with DataType UInt16 is an identifier for the WriterGroup and shall be unique across all WriterGroups for a PublisherId. All values, except for 0, are valid. The value 0 is defined as null value.

6.2.5.2 PublishingInterval ToC

The PublishingInterval with the DataType Duration defines the interval in milliseconds for publishing NetworkMessages and the embedded DataSetMessages created by the related DataSetWriters.

In the case of Event based DataSets, this may result in zero to many DataSetMessages produced for one PublishedDataSet in a PublishingInterval. All Events that occur between two PublishingIntervals shall be buffered until the next NetworkMessage is sent. If the number of Events exceeds the buffer capability of the DataSetWriter, an Event of type EventQueueOverflowEventType is inserted into the buffer.

The Duration DataType is a subtype of Double and allows configuration of intervals smaller than a millisecond.

6.2.5.3 KeepAliveTime ToC

The KeepAliveTime with DataType Duration defines the time in milliseconds until the Publisher sends a keep alive DataSetMessage in the case where no DataSetMessage was sent in this period by a DataSetWriter. The minimum value shall equal the PublishingInterval.

6.2.5.4 Priority ToC

The Priority with DataType Byte defines the relative priority of the WriterGroup to all other WriterGroups across all PubSubConnections of the Publisher.

If more than one WriterGroup needs to be processed, the priority number defines the order of processing. The highest priority is processed first.

The lowest priority is zero and the highest is 255.

6.2.5.5 LocaleIds ToC

The LocaleIds with DataType LocaleId defines a list of locale ids in priority order for localized strings for all DataSetWriters in the WriterGroup. The first LocaleId in the list has the highest priority.

If the Publisher sends a localized String, the Publisher shall send the translation with the highest priority that it can. If it does not have a translation for any of the locales identified in this list, then it shall send the String value that it has and include the LocaleId with the String. If no locale id is configured, the Publisher shall use any that it has. See OPC 10000-3 for more detail on LocaleId.

6.2.5.6 WriterGroup Structures ToC Model

6.2.5.6.1 WriterGroupDataType ToC Model

This Structure DataType is used to represent the configuration parameters for WriterGroups. It is a subtype of PubSubGroupDataType defined in 0.

The WriterGroupDataType is formally defined in Table 22.

Table 22 – WriterGroupDataType Structure

Name Type Description
WriterGroupDataType Structure  
 writerGroupId UInt16 Defined in 6.2.5.1.
 publishingInterval Duration Defined in 6.2.5.2.
 keepAliveTime Duration Defined in 6.2.5.3.
 priority Byte Defined in 6.2.5.4.
 localeIds LocaleId[] Defined in 6.2.5.5.
 headerLayoutUri String  
 transportSettings WriterGroupTransportDataType Transport mapping specific WriterGroup parameters. The abstract base type is defined in 6.2.5.6.2. The concrete subtypes are defined in the sections for transport mapping specific parameters.
 messageSettings WriterGroupMessageDataType NetworkMessage mapping specific WriterGroup parameters. The abstract base type is defined in 6.2.5.6.3. The concrete subtypes are defined in the sections for message mapping specific parameters.
 dataSetWriters DataSetWriterDataType[] The DataSetWriters contained in the WriterGroup. The DataSetWriter parameters are defined in 6.2.3.

The WriterGroupDataType Structure representation in the AddressSpace is defined in Table 23.

Table 23 – WriterGroupDataType Definition

Attributes Value    
BrowseName WriterGroupDataType    
IsAbstract False    
References NodeClass BrowseName IsAbstract
Subtype of PubSubGroupDataType defined in 0.      

6.2.5.6.2 WriterGroupTransportDataType ToC Model

This Structure DataType is an abstract base type for transport mapping specific WriterGroup parameters. The abstract DataType does not define fields.

The WriterGroupTransportDataType Structure representation in the AddressSpace is defined in Table 24.

Table 24 – WriterGroupTransportDataType Definition

Attributes Value      
BrowseName WriterGroupTransportDataType      
IsAbstract True      
References NodeClass BrowseName IsAbstract Description
Subtype of Structure defined in OPC 10000-5.        
HasSubtype DataType DatagramWriterGroupTransportDataType FALSE Defined in 6.4.1.2.3.
HasSubtype DataType BrokerWriterGroupTransportDataType FALSE Defined in 6.4.2.2.6.

6.2.5.6.3 WriterGroupMessageDataType ToC Model

This Structure DataType is an abstract base type for message mapping specific WriterGroup parameters. The abstract DataType does not define fields.

The WriterGroupMessageDataType Structure representation in the AddressSpace is defined in Table 25.

Table 25 – WriterGroupMessageDataType Structure

Attributes Value      
BrowseName WriterGroupMessageDataType      
IsAbstract True      
References NodeClass BrowseName IsAbstract Description
Subtype of Structure defined in OPC 10000-5.        
HasSubtype DataType UadpWriterGroupMessageDataType FALSE Defined in 6.3.1.1.7.
HasSubtype DataType JsonWriterGroupMessageDataType FALSE Defined in 6.3.2.1.2.

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