F.11.2.2 SET General Purpose Performed Procedure Step Information

This operation allows an SCU to set Attribute Values of an instance of the General Purpose Performed Procedure Step SOP Class and provide information about a specific real-world General Purpose Performed Procedure Step that is under control of the SCU. This operation shall be invoked through the DIMSE N-SET Service.

F.11.2.2.1 General Purpose Performed Procedure Step IOD Subset Specification

The Application Entity which claims conformance to this SOP Class as an SCU may choose to modify a subset of the Attributes maintained by the SCP. The Application Entity which claims conformance as an SCP to this SOP Class shall support the subset of the General Purpose Performed Procedure Step Attributes specified in Table F.11.2-1.

The character set used for Attribute Values updated using the N-SET shall be the same as that specified by the N-CREATE Request Primitive.

F.11.2.2.2 Service Class User

The SCU shall specify in the N-SET request primitive the UID of the General Purpose Performed Procedure Step SOP Instance for which it wants to set Attribute Values.

The SCU shall be permitted to set Attribute values for any General Purpose Performed Procedure Step SOP Class Attribute specified in Table F.11.2-1. The SCU shall specify the list of General Purpose Performed Procedure Step SOP Class Attributes for which it wants to set the Attribute Values. The SCU shall provide, with one or more N-SET request primitives, the attribute values specified in Table F.11.2-1. The encoding rules for General Purpose Performed Procedure Step Attributes are specified in the N-SET request primitive specification in PS 3.7. The SCU shall only set Attribute Values which are already created with an N-CREATE request.

The SCU shall not send N-SET request primitives for a General Purpose Performed Procedure Step SOP Instance after a N-SET request primitive with a value for the attribute “General Purpose Performed Procedure Step Status” (0040,4002) is “COMPLETED” or “DISCONTINUED” has been sent.

Once the General Purpose Performed Procedure Step Status (0040,4002) has been set to “COMPLETED” or “DISCONTINUED” the SCU shall no longer modify the General Purpose Performed Procedure Step SOP Instance, and shall not create new Composite SOP Instances as part of the same General Purpose Performed Procedure Step SOP Instance.

If Sequences are included in a N-SET command, all Items of a Sequence are to be included in the command and not only the Items to be updated.

Before or when General Purpose Performed Procedure Step Status (0040,4002) is set to “COMPLETED” or “DISCONTINUED” the SCU shall have created or set all the Attributes according to the requirements in the Final State column of Table F.11.2-1.

Before or when General Purpose Performed Procedure Step Status (0040,4002) is set to “COMPLETED” or “DISCONTINUED” the SCU shall have sent to the SCP a list of all Composite SOP Instances created during the Procedure Step in Output Information Sequence (0040,4033).

Note: The intent is that a completed or discontinued General Purpose Performed Procedure Step entity will contain a complete list of all the Composite Instances that were created.

The General Purpose Performed Procedure Step Status (0040,4002) shall not be set to “COMPLETED” or “DISCONTINUED” if the list contains no Composite Instance references, unless no such Instances were created.

F.11.2.2.3 Service Class Provider

The N-SET operation allows the SCU to request that the SCP update selected Attribute values for a specific General Purpose Performed Procedure Step SOP Instance. This operation shall be invoked through the use of the DIMSE N-SET Service used in conjunction with the appropriate General Purpose Performed Procedure Step SOP Instance.

The SCP shall return, via the N-SET response primitive, the N-SET Response Status Code applicable to the associated request. Contingent on the N-SET Response Status, the SCP shall update the Referenced Performed Procedure Step Attributes.

The SCP shall accept N-SET request primitives only if the value of the already existing attribute “General Purpose Performed Procedure Step Status” (0040,4002) is “IN PROGRESS”. If the already existing General Purpose Performed Procedure Step Status attribute has another value, the SCP shall send the failure status code as specified in Section F.11.2.2.4.

The SCP may itself modify any Attributes of the General Purpose Performed Procedure Step SOP Instance only after the “General Purpose Performed Procedure Step Status” (0040,4002) has been set to “COMPLETED” or “DISCONTINUED”, or when error conditions require such a modification.

Note: Under exceptional circumstances, it may be necessary for the SCP to itself set the Performed Procedure Step Status (0040,0252) to COMPLETED or DISCONTINUED, for example if the performing device has failed. When the SCU recovers, subsequent N-SETs may fail.

F.11.2.2.4 Status Codes

The status values which are specific for this SOP Class are defined in Table F.11.2-3a.

Table F.11.2-3a SOP CLASS STATUS VALUES

Service Status Meaning Status Code
Failure Refused because the General Purpose Performed Procedure Step SOP Instance is not in the “IN PROGRESS” state A506