The N-ACTION is used to print the film session; i.e. to print all the films which belong to the film session.
If multiple copies of the film session have been requested, the SCP shall collate the copies. This means that if two copies of four films has been specified, the printed sequence is 12341234.
The arguments of the N-ACTION are defined in Table H.4-3.
The Action Reply argument is encoded as a DICOM Data Set. The Data Set only contains the Attribute Referenced Print Job Sequence (2100,0500) which includes the Referenced SOP Class UID (0008,1150) and the Referenced SOP Instance UID (0008,1155).
If the SCP supports the Print Job SOP Class, the Action Reply argument is contained in the N-ACTION response. Otherwise, the Action Reply is not contained in the N-ACTION response.
Table H.4-3 N-ACTION ARGUMENTS
|Action Type Name||Action Type ID||Attribute||Tag||Usage SCU/SCP|
|1||Referenced Print Job Sequence||(2100,0500)||-/MC Required if Print Job SOP is supported|
|>Referenced SOP Class UID||(0008,1150)||-/MC Required if Referenced Print Job Sequence (2100,0500) is present|
|>Referenced SOP Instance UID||(0008,1155)||-/MC Required if Referenced Print Job Sequence (2100,0500) is present|
The status values which are specific for this SOP Class are defined in Table H.4-4.
Table H.4-4 SOP CLASS STATUS VALUES
|Success||Film belonging to the film session are accepted for printing; if supported, the Print Job SOP Instance is created||0000|
|Warning||Film session printing (collation) is not supported||B601|
|Film Session SOP Instance hierarchy does not contain Image Box SOP Instances (empty page)||B602|
|Image size is larger than image box size, the image has been demagnified.||B604|
|Image size is larger than the Image Box size. The Image has been cropped to fit.||B609|
|Image size or Combined Print Image size is larger than the Image Box size. Image or Combined Print Image has been decimated to fit.||B60A|
|Failure||Film Session SOP Instance hierarchy does not contain Film Box SOP Instances||C600|
|Unable to create Print Job SOP Instance; print queue is full||C601|
|Image size is larger than image box size||C603|
|Combined Print Image size is larger than the Image Box size||C613|
Note: Previous versions of the DICOM Standard defined the status code of C604. This code was specified for the case of an image position collision. Since image position collision is not a possible state, the code has been retired.
The SCU uses the N-ACTION to request the SCP to print all the films belonging to the identified film session.
The SCP shall make a copy of the “working” Basic Film Session SOP Instance hierarchy, which contains all the information to control the Print Process. Hence the SCU may further update the “working” SOP Instance hierarchy without affecting the result of previous print requests. The execution of the Print Process is monitored by the Print Job SOP Instance (if supported by the SCP) and the Printer SOP Class.
If the SCP supports the Print Job SOP Class then the SCP shall create a Print Job SOP Instance, which contains the copy of the “working” Basic Film Session SOP Instance hierarchy and shall return the Print Job SOP Class/Instance UID pair in the Attribute Referenced Print Job Sequence of the Action Reply argument.
Note: If the SCP supports the Print Job SOP Class, it creates a single Print Job for all the films of the film session.
The SCP shall return the status code of the requested operation. The meaning of success, warning, and failure status codes is defined in Section H.2.5.
The N-ACTION shall be issued only if the Basic Film Session SOP Instance hierarchy contains at least one Film Box SOP Instance.