Creating a DICOM Associate Connection

Once a DICOM Network Connection has been established, a DICOM Associate Connection must be established before DICOM messages and data can be transferred between two AEs.

The AE acting as an SCP must have a DICOM Associate handle and the AE acting as an SCU must have a DICOM Associate handle. Steps for establishing a DICOM Associate connection are given below for both the SCU and the SCP.

Creating an associate handle for an SCU

• Create the DICOM Associate handle by calling L_DicomCreateAssociate.

• Initialize the newly created DICOM Associate handle by calling L_DicomDefaultAssociate, or set the new DICOM Associate handle using the following functions:

  • L_DicomSetRequest
  • L_DicomSetVersion
  • L_DicomSetCalled
  • L_DicomSetCalling
  • L_DicomSetApplication
  • L_DicomSetPresentation
  • L_DicomSetResult
  • L_DicomSetAbstract
  • L_DicomSetTransfer
  • L_DicomSetMaxLength
  • L_DicomSetImplementClass
  • L_DicomSetAsyncOperations
  • L_DicomSetRoleSelect
  • L_DicomSetImplementVersion
  • L_DicomSetUserInfo
  • L_DicomSetExtended
  • L_DicomAddPresentation
  • L_DicomAddTransfer

• To connect to an SCP, call L_DicomSendAssociateRequest. This will generate a call to the RECEIVEASSOCIATEREQUESTCALLBACK on the SCP to let the SCP know an associate connection request has been received.

• The SCP may accept or reject the request and respond by calling L_DicomSendAssociateAccept or L_DicomSendAssociateReject. This will generate a call to the RECEIVEASSOCIATEACCEPTCALLBACK or the RECEIVEASSOCIATEREJECTCALLBACK. If RECEIVEASSOCIATEACCEPTCALLBACK is called, the DICOM Associate Connection has been established.

Creating an associate handle for an SCP

• When an SCU requests a DICOM Associate connection, the SCU calls L_DicomSendAssociateRequest. This generates a call to RECEIVEASSOCIATEREQUESTCALLBACK on the SCP.

• When the RECEIVEASSOCIATEREQUESTCALLBACK function is called, create the DICOM Associate handle by calling L_DicomCreateAssociate.

• Reset the newly created DICOM Associate handle to an Associate Accept by calling L_DicomResetAssociate, or set the new DICOM Associate handle using the functions given above.

• The DICOM Associate connection request can be accepted or rejected. To accept the Associate connection request, call L_DicomSendAssociateAccept. This will generate a call to the RECEIVEASSOCIATEACCEPTCALLBACK on the SCU. At this time the DICOM Associate connection has been established. To reject the Associate connection request, call L_DicomSendAssociateReject. This will generate a call to the RECEIVEASSOCIATEREJECTCALLBACK function on the SCU.

Freeing allocated memory

When the DICOM Associate handle is no longer needed, call L_DicomFreeAssociate to free the memory allocated for the specified DICOM Associate.