This ObjectType represents a FileType the can be used to access a PubSub configuration. The PubSubConfigurationType is formally defined in Table 211.
The PubSubConfigurationType file is a UA Binary encoded stream containing an instance of UABinaryFileDataType that contains a PubSubConfiguration2DataType or subtype as Body. The UABinaryFileDataType is defined in OPC 10000-5. The PubSubConfiguration2DataType is defined in 6.2.12.4. The indices of the namespaces in the PubSubConfiguration2DataType and the Namespaces in the DataTypeSchemaHeader of the UABinaryFileDataType shall match the NamespaceArray in the OPC UA Server for a Session with the Server.
The FileType functionality is used instead of passing the PubSubConfiguration2DataType to read and write Methods to overcome potential limitations of communication buffers for OPC UA Service calls. It is expected that the PubSubConfiguration2DataType is used internally in Client and Server and that the FileType is only used to be able to transfer large configurations.
The Open Method shall not support modes other than Read (0x01), Write + EraseExisting (0x06) and Read + Write (0x03).
When a Client opens the file for writing the Server will not actually update the PubSub configuration until the CloseAndUpdate Method is called. Simply calling Close will discard the updates.
When a Client opens the file for reading and writing, the Client shall follow the following steps.
- Read the existing configuration with the FileType Read Method.
- Set the position to the beginning of the file with the FileType SetPosition Method.
- Write the changes with the FileType Write Method.
- Apply the changes with the CloseAndUpdate Method.
Access to the PubSub configuration may be used by multiple Clients in parallel. Read access can be done in parallel but open with the Write flag set requires exclusive access. Therefore Clients that have the file open should minimize the time the file is open to the currently required actions. The Client shall close the file as soon as it completes the sequence of actions needed to read or write the file. Clients with a user interface shall not keep the file open for user configuration. Such Clients should read and close the file to initialize the user interface. If the user changes should be written to the PubSub configuration, the Client should open the file with Read + Write (0x03), read the file, compare the version information and then write the changes if the version matches the version from the intial read.
Table 211 – PubSubConfigurationType definition
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Attribute |
Value |
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BrowseName |
PubSubConfigurationType |
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IsAbstract |
False |
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References |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
ModellingRule |
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Subtype of FileType defined in OPC 10000-20. |
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HasComponent |
Method |
ReserveIds |
Defined in 9.1.3.7.5. |
Mandatory |
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|
HasComponent |
Method |
CloseAndUpdate |
Defined in 9.1.3.7.6. |
Mandatory |
|
|
Conformance Units |
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|
PubSub Model Base |
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