The WoTAssetConnectionManagementType ObjectType represents a set of WoTAssets that may be managed by a Server. It is defined in Table 5.
Table 5 – WoTAssetConnectionManagementType Definition
|
Attribute |
Value |
||||
|
BrowseName |
WoTAssetConnectionManagementType |
||||
|
IsAbstract |
False |
||||
|
References |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
Other |
|
Subtype of the 0:BaseObjectType defined in OPC 10000-5. |
|||||
|
0:Organizes |
Object |
<WoTAssetName> |
|
BaseObjectType |
OP |
|
0:HasComponent |
Method |
CreateAsset |
Defined in 6.3.2 |
M |
|
|
0:HasComponent |
Method |
DeleteAsset |
Defined in 6.3.1.3. |
M |
|
|
|
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|
Conformance Units |
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|
WoT Connectivity Base Functionality |
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Any instance of the <WoTAssetName> Object shall implement the IWoTAssetType Interface.
The CreateAsset Method creates a new Object that implements the IWoTAssetType Interface organized by the WoTAssetConnectionManagement Object.
The DeleteAsset Method shall remove the Organizes Reference from the WoTAssetConnectionManagement Object and may delete the IWoTAssetType instance.
The components of the WoTAssetConnectionManagementType have additional references which are defined in Table 6.
Table 6 – WoTAssetConnectionManagementType Additional References
|
SourceBrowsePath |
Reference Type |
Is Forward |
TargetBrowsePath |
|
<WoTAssetName> |
0:HasInterface |
True |
IWoTAssetType |
CreateAsset creates a new Object that implements the IWoTAssetType Interface that can be used to upload the WoT TD file to the server. Once the upload is complete, the industrial asset becomes reachable via the OPC UA server. The WoT TD file uploaded fully defines the endpoint, protocol, and all asset tags to be mapped to OPC UA.
CreateAsset, when successful, returns the NodeId of the newly created Object and adds an Organizes Reference from the WoTAssetConnectionManagement Object.
Signature
CreateAsset(
[in] 0:String AssetName,
[out] 0:NodeId AssetId);
Table 7 – CreateAsset Method Arguments
|
Argument |
Description |
|
AssetName |
A unique name for the asset. |
|
AssetId |
The NodeId of the WoTAsset Object, if call was successful. |
Method Result Codes
|
Result Code Symbolic Id |
Description |
|
Bad_BrowseNameDuplicated |
The AssetName is already used. |
|
Bad_UserAccessDenied |
The session does not have the permissions required. |
DeleteAsset deletes a previously configured industrial asset. It takes the NodeId of a WoTAsset Object input, previously returned by CreateAsset. These NodeIds can also be browsed from the WoTAssetConnectionManagement instance.
Signature
DeleteAsset(
[in] 0:NodeId AssetId);
Table 8 – DeleteAsset Method Arguments
|
Argument |
Description |
|
AssetId |
The NodeId of the WoTAsset Object. |
Method Result Codes
|
Result Code Symbolic Id |
Description |
|
Bad_NotFound |
The asset was not found. |
|
Bad_InvalidArgument |
The NodeId provided was invalid. |
|
Bad_UserAccessDenied |
The session does not have the permissions required. |
The IWoTAssetType is an Interface representing the WoT asset functionality. It has a component representing a File Object that can be used to upload the WoT TD file. It is defined in Table 9.
Table 9 – IWoTAssetType Definition
|
Attribute |
Value |
||||
|
BrowseName |
IWoTAssetType |
||||
|
IsAbstract |
True |
||||
|
References |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
Other |
|
Subtype of the 0:BaseInterfaceType defined in OPC 10000-5. |
|||||
|
1:HasWoTComponent |
Variable |
<WoTPropertyName> |
0:BaseDataType |
0:BaseDataVariableType |
OP |
|
0:HasComponent |
Object |
WoTFile |
|
WoTAssetFileType |
M |
|
|
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|
Conformance Units |
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|
WoT Connectivity Base Functionality |
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When the asset configuration is complete, the Server may update the internal configuration of existing Variable Nodes or it may add new Variable Nodes to represent the asset. Each WoT property in the forms section of the TD shall have exactly one VariableNode associated with it.
The WoTAsset Object must have hierarchical HasWoTComponent references to the newly created Variable Nodes, one for each WoT property.
The BrowseName of the Variable Node shall have a name equal to the WoT property name.
If a mapping to a WoT property cannot be done (e.g. the data cannot be read from the connected asset), the built-in status code Bad_ConfigurationError will be returned when the Value of the Variable is read.
Each WoT property type is mapped to the corresponding OPC UA built-in DataType using the following mapping table:
Table 10 – WoT property type mapping
|
WoT Property Type |
OPC UA Data Type |
|
Boolean |
Boolean |
|
Number |
Double |
|
Integer |
Int64 |
|
Object |
No mapping |
|
String |
String |
|
Null |
No mapping |
|
Array[Items] |
Array[of one of above defined types] |
The WoTAssetFileType ObjectType represents a set of TD File that is used to define an WoTAsset. It is defined in Table 11.
All instances shall support a mode of Write + EraseExisting when Open is called. They may support mode of Read. Other modes are not allowed.
When writing, if Close is called the file is discard and nothing changes. If CloseAndUpdate is called the file is parsed and the variables are updated to match the WoT TD file.
Table 11 – WoTAssetFileType Definition
|
Attribute |
Value |
||||
|
BrowseName |
WoTAssetFileType |
||||
|
IsAbstract |
False |
||||
|
References |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
Modelling Rule |
|
Subtype of the 0:FileType defined in OPC 10000-5. |
|||||
|
0:HasComponent |
Method |
CloseAndUpdate |
Defined in 6.3.3.2 |
Mandatory |
|
|
|
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|
Conformance Units |
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|
WoT Connectivity Base Functionality |
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The CloseAndUpdate Method parses the TD and creates Variables from the TD properties.
CloseAndUpdate Method parses the TD and creates Variables from the TD properties.
Signature
CloseAndUpdate (
[in] 0:UInt32 FileHandle
);
Table 12 – CloseAndUpdate Method Arguments
|
Argument |
Description |
|
FileHandle |
The handle for a file opened for writing. |
Method Result Codes
|
Result Code Symbolic Id |
Description |
|
Bad_InvalidState |
The file was not opened for writing. |
|
Bad_DecodingError |
The WoT Thing Description could not be parsed. |
|
Bad_NotSupported |
The TD is valid but cannot be mapped to OPC UA. |
|
Bad_NotFound |
The asset was not found on the network. |
|
Bad_UserAccessDenied |
The session does not have the permissions required. |
The HasWoTComponent is a concrete ReferenceType used to link WoT asset Objects to the WoT properties. The source node shall be an instance of an Object implementing the IWoTAssetType Interface. The target Node shall be an instance or a subtype of a BaseDataVariableType.
The HasWoTComponent representation in the AddressSpace is specified in Table 13.
Table 13 – HasWoTComponent ReferenceType
|
Attributes |
Value |
||
|
BrowseName |
HasWoTComponent |
||
|
InverseName |
WoTComponentOf |
||
|
Symmetric |
False |
||
|
IsAbstract |
False |
||
|
References |
NodeClass |
BrowseName |
Comment |
|
Subtype of 0:HasComponent ReferenceType defined in OPC 10000-5. |
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|
Conformance Units |
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|
WoT Connectivity Base Functionality |
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