The parameterPublishedDatadefines the content of a DataSetcreated from Variable Valuesand therefore the content of the DataSetMessagesent by aDataSetWriter. The sources of the DataSet fields are defined through an array of PublishedVariableDataType.
The index into the array has an important role for Subscribersand for configuration tools. It is used as a handle to reference the Valuein DataSetMessagesreceived by Subscribers. The index may change after configuration changes. Changes are indicated by the ConfigurationVersionof the DataSetand applications working with the index shall always check the ConfigurationVersionbefore using the index.
If an entry of the PublishedDatareferences one of the ExtensionFields, the substituteValueshall contain the QualifiedName of the ExtensionFields entry. All other fields of this PublishedVariableDataTypearray element shall be null.
The DataType PublishedVariableDataTyperepresents the configuration information for one Variable. The PublishedVariableDataTypeis formally defined in Table 11.
Table 11– PublishedVariableDataType Structure
|
Name |
Type |
Description |
|
PublishedVariableDataType |
Structure |
|
|
publishedVariable |
NodeId |
The NodeIdof the published Variable. Some transport protocols require knowledge on the message receiver side about the DataType, ValueRank and ArrayDimensions to be able to decode the message content. This information is provided through the DataSetMetaDataprovided for the DataSet. |
|
attributeId |
IntegerId |
Id of the Attributeto publish e.g. the Value Attribute. This shall be a valid Attributeid. The Attributesare defined in OPC 10000-3. The IntegerId DataType is defined in OPC 10000-4. The IntegerIdsfor the Attributesare defined in OPC 10000-6. |
|
samplingIntervalHint |
Duration |
A recommended rate of acquiring new values for change or deadband evaluation. A Publishershould use this value as hint for setting the internal sampling rate. The value 0 indicates that the Servershould use the fastest practical rate. The value -1 indicates that the default sampling interval defined by the PublishingIntervalof the WriterGroup is requested. Any negative number is interpreted as -1. |
|
deadbandType |
UInt32 |
A value that defines the Deadbandtype and behaviour. Value Description None_0 No Deadbandcalculation should be applied. Absolute_1 AbsoluteDeadband (This type is specified in OPC 10000-4) Percent_2 PercentDeadband (This type is specified in OPC 10000-8). |
|
deadbandValue |
Double |
The deadband value for the corresponding DeadbandType. The meaning of the value depends on DeadbandType. |
|
indexRange |
NumericRange |
This parameter is used to identify a single element of an array, or a single range of indexes for arrays. The NumericRangetype and the logic for IndexRangeare defined in OPC 10000-4.
|
|
substituteValue |
BaseDataType |
The value that is included in the DataSetif the StatusCodeof the DataValueis Bad. In this case the StatusCodeis set to Uncertain_SubstituteValue. This Value shall match the DataTypeof the PublishedVariablesince DataSetWritersmay depend on a valid Valuewith the right DataTypethat matches the ConfigurationVersion. If the SubstituteValueis Null, the StatusCodeof the DataValueis processed. The handling of the SubstituteValueis defined in 6.2.10. |
|
metaDataProperties |
QualifiedName [ ] |
This parameter specifies an array of Propertiesto be included in the FieldMetaDatacreated for this Variable. It shall be used to populate the propertieselement of the resulting field in the DataSetMetaData. |