DNP3 data objects in the protection relay are all unmapped as default. Using the Communication Management tool in PCM600, the objects can be freely added and located into the DNP3 memory map.
The available DNP3 data objects are taken (mapped) entirely from the native IEC 61850 application data available in the protection relay. Mainly the IEC 61850 data that resides in IEC 61850 default dataset is included in the DNP3 object mapping. Objects within IEC 61850 datasets produce time tagged events. IEC 61850 events and time stamps are propagated into DNP3 class events.
Some IEC 61850 objects, which do not reside in any IEC 61850 dataset, have also been mapped to DNP3. Since these objects do not create any events upon change, it is not possible to assign them into any event class (1...3) in DNP3. The Communication Management tool prevents this kind of assignment. These objects are in the point list referred to as “Static-only” objects. The controlling station can read them on demand directly from the object group in question, or they can be assigned to DNP3 Class 0.
The protection relay includes a predefined set of available function blocks, which in turn includes data objects that are visible for the DNP3 protocol. However, only a part of these function blocks can be used by the protection relay's application configuration. The Communication Management tool shows only the DNP3 objects that are active in the configuration. Not all the available function blocks are included in the default application configuration.
- If a function block is removed from the configuration, the DNP3 objects belonging to this function block are automatically removed from the DNP3 point list. If points are mapped to a DNP3 object address, a “hole” in the mapping occurs. In such case, the remaining map can be modified with the Communication Management tool.
- If a function block is added, the DNP3 points from this function block appear as unmapped in the Communication Management tool.