ResultTransferType – OPC UA for Machine Vision – Part 1: Control, configuration management, recipe management, result management

7.12 ResultTransferType

7.12.1 Overview

This ObjectType is a subtype of the TemporaryFileTransferType defined in OPC 10000-5 and is used to transfer result data as a file.

The ResultTransferType overwrites the Method GenerateFileForRead to specify the concrete type of the generateOptions Parameter of the Methods. It does not specialize the GenerateFileForWrite method of the base type as results are supposed to be only generated by the vision system, not received.

Figure 19 shows the hierarchical structure and details of the composition. It is formally defined in Table 75.

Table 75 – Definition of ResultTransferType

Attribute	Value
BrowseName	ResultTransferType
IsAbstract	False

References	NodeClass	BrowseName	DataType	TypeDefinition	ModellingRule
Subtype of the TemporaryFileTransferType defined in OPC 10000-5
HasComponent	Method	0:GenerateFileForRead	--	--	Mandatory

7.12.2 ResultTransferType methods

7.12.2.1 GenerateFileForRead

This method is used to start the read file transaction. A successful call of this method creates a temporary FileType Object with the file content and returns the NodeId of this Object and the file handle to access the Object.

Signature

	GenerateFileForRead ([in]	ResultTransferOptions	generateOptions[out]	NodeId	fileNodeId[out]	UInt32	fileHandle[out]	NodeId	completionStateMachine);

Table 76 – GenerateFileForRead Method Arguments

Argument	Description
generateOptions	The structure used to define the generate options for the file.
fileNodeId	NodeId of the temporary file
fileHandle	The FileHandle of the opened TransferFile. The FileHandle can be used to access the TransferFile methods Read and Close.
completionStateMachine	If the creation of the file is completed asynchronously, the parameter returns the NodeId of the corresponding FileTransferStateMachineType Object. If the creation of the file is already completed, the parameter is null. If a FileTransferStateMachineType object NodeId is returned, the Read Method of the file fails until the TransferState changed to ReadTransfer.

Table 77 – GenerateFileForRead Method AddressSpace Definition

Attribute	Value
BrowseName	GenerateFileForRead

References	NodeClass	BrowseName	DataType	TypeDefinition	ModellingRule
HasProperty	Variable	InputArguments	Argument[]	PropertyType	Mandatory
HasProperty	Variable	OutputArguments	Argument[]	PropertyType	Mandatory