6.3.1.2 SNRequestUnassigned Method

SNRequestUnassigned –This Method requests unassigned serial numbers from an OPC UA Server that is performing serial number management for a specific Serial Number Collection.

The signature of this Method is specified below. Table 5 and Table 6 specify the Arguments and AddressSpace representation, respectively.

Signature 

	SNRequestUnassigned (
		[in]	String				SNCollectionID
	[in]	UInt32				Count
	[in]	String				SNFormat
	[in]	OPENSCSKeyValueDataType[]	PoolSelectionCriteria
	[in]	String			   	RequestToken
	[out]	OPENSCSReturnEnum	   	ReturnStatus
	[out]	OPENSCSSNCollectionDataType 	SNCollection
	[out]	String			   	ReturnedRequestToken
	);
Table 5 – SNRequestUnassigned Method Arguments
ArgumentDescription
SNCollectionID

Identifies the Serial Number Collection from which unassigned Serial Numbers are to be provided.

If the Serial Number Collection ID does not match a Serial Number Collection managed by the Information Provider, then an “Invalid Serial Number Collection” error is returned.

If the Serial Number Collection ID is not provided, then the default Serial Number Collection shall be selected.

Count

Identifies the number of Serial Numbers requested.

If fewer Serial Numbers are available from the pool, then are requested, then an “Insufficient Serial Numbers” status is returned, and the number of Serial Numbers that are available are returned.

SNFormat

Defines the desired serial number format (see the OPENSCS PSS Specification for format definitions) for the requested serial numbers.

If the Serial Number Format is not known to the server, then an “Invalid Serial Number Format” error is returned.

PoolSelectionCriteria

Identified value to be used by the method provider to determine which Serial Numbers to return.

If no Pool Selection Criteria is defined, then the default Pool Selection Criteria of the method provider is used.

If the pool selection criteria is not known to the server, then an “Invalid selection Criteria” error is returned.

RequestToken

If it has a value of null, then this is the initial request for Serial Numbers.

If the value is not null, then this is a follow-on request because the number of Serial Numbers requested in a previous call were not available as an immediate response.

RequestTokens are provided to 1) support asynchronous transactions, where there can be delays between requests and the availability of Serial Numbers, and 2) where more Serial Numbers are requested than can be exchanged in a single transaction.

If the Request Token has a value not understood by the Information Provider, then an “Invalid Parameter” error is returned.

ReturnStatusReturns the status of the method execution.
SNCollectionContains requested Serial Number collection with Serial Numbers of the specified state. If no serial numbers are returned (not available), then this argument returns null.
ReturnedRequestToken

If null or an empty string, then all requested numbers have been sent.

If non null or an empty string, then there are more serial numbers to be returned and the returned Request Token is to be passed as an input parameter on a subsequent call.

Method Result Codes are defined as part of the Call service (see OPC 10000-4 and Table 95).

Table 6 – SNRequestUnassigned Method AddressSpace Definition
Attribute Value
BrowseNameSNRequestUnassigned
IsAbstractTrue
References NodeClass BrowseName DataType TypeDefinition ModellingRule
0:HasPropertyVariableInputArgumentsArgument[]0:PropertyTypeMandatory
0:HasPropertyVariableOutputArgumentsArgument[]0:PropertyTypeMandatory