Display System Management Service Examples

The DICOM Display System Management Service allows an Application Entity to retrieve Display Subsystem parameters from a peer by using the N-GET service. It only has a single supported SOP Class.

Display System Management SCU

Associate with a peer DICOM Application Entity and request the use of the Display System Management Service.

from pynetdicom import AE
from pynetdicom.sop_class import DisplaySystemSOPClass
from pynetdicom.status import code_to_category

# Initialise the Application Entity
ae = AE()

# Add a requested presentation context
ae.add_requested_context(DisplaySystemSOPClass)

# Associate with peer AE at IP 127.0.0.1 and port 11112
assoc = ae.associate('127.0.0.1', 11112)

if assoc.is_established:
    # Use the N-GET service to send the request, returns the
    #  response status a pydicom Dataset and the AttributeList dataset
    status, attr_list = assoc.send_n_get(
        [(0x0008,0x0070)],
        DisplaySystemSOPClass,
        '1.2.840.10008.5.1.1.40.1'
    )

    # Check the status of the display system request
    if 'Status' in status:
        print('N-GET request status: 0x{0:04x}'.format(status.Status))

        # If the display system request succeeded the status category may
        # be either success or warning
        category = code_to_category(status.Status)
        if category in ['Warning', 'Success']:
            # `attr_list` is a pydicom Dataset containing attribute values
            print(attr_list)
    else:
        print('Connection timed out or invalid response from peer')

    # Release the association
    assoc.release()
else:
    print('Association rejected or aborted')

You can also use the inbuilt DisplaySystemPresentationContexts when setting the requested contexts.

from pynetdicom import AE, DisplaySystemPresentationContexts

ae = AE()
ae.requested_contexts = DisplaySystemPresentationContexts

Display System Management SCP

The following represents a toy implementation of a Display System Management SCP, where the SCU has sent a request with an Attribute Identifier List containing the single tag (0008,0070).

from pynetdicom import AE
from pynetdicom.sop_class import DisplaySystemSOPClass

# Initialise the Application Entity and specify the listen port
ae = AE(port=11112)

# Add the supported presentation context
ae.add_supported_context(DisplaySystemSOPClass)

def on_n_get(attr, context, info):
    """Callback for when an N-GET request is received.

    Parameters
    ----------
    attr : list of pydicom.tag.Tag
        The value of the (0000,1005) *Attribute Idenfier List* element
        containing the attribute tags for the N-GET operation.
    context : presentation.PresentationContextTuple
        The presentation context that the N-GET message was sent under.
    info : dict
        A dict containing information about the current association.

    Returns
    -------
    status : pydicom.dataset.Dataset or int
        The status returned to the peer AE in the N-GET response. Must be a
        valid N-GET status value for the applicable Service Class as either
        an ``int`` or a ``Dataset`` object containing (at a minimum) a
        (0000,0900) *Status* element. If returning a Dataset object then
        it may also contain optional elements related to the Status (as in
        DICOM Standard Part 7, Annex C).
    dataset : pydicom.dataset.Dataset or None
        If the status category is 'Success' or 'Warning' then a dataset
        containing elements matching the request's Attribute List
        conformant to the specifications in the corresponding Service
        Class.

        If the status is not 'Successs' or 'Warning' then return None.
    """
    # User defined function to generate the required attribute list dataset
    # implementation is outside the scope of the current example
    # We pretend it returns a pydicom Dataset
    dataset = create_attribute_list(attr)

    # If Display System Management returns an attribute list then the
    # SOP Class UID and SOP Instance UID must always be as given below
    assert dataset.SOPClassUID = '1.2.840.10008.5.1.1.40'
    assert dataset.SOPInstanceUID = '1.2.840.10008.5.1.1.40.1'

    # Return status, dataset
    return 0x0000, dataset

ae.on_n_get = on_n_get

# Start listening for incoming association requests
ae.start()