Return value
The current MAC type used by the sender. Possible values are:
| Value | Meaning | 
| DICOM_ISCL_MAC_NONE | No message authentication code was used. | 
| DICOM_ISCL_MAC_MD5 | A 128 bit MD5 message authentication code was transmitted with the message. | 
| DICOM_ISCL_MAC_DESMAC | A 64 bit DESMAC authentication code was transmitted with the message. |