Sunday, May 24, 2009

MMS Reports with or without Segmentation?

A utility specified for IEC 61850 conformant IEDs, that all the data of FC=SG are referenced in a single dataset, to make the setting group value easily read in one GetDataSetValues service. But once the data objects are too many so that one MMS PDU can't carry the values of all members, is there any method to help transmit the values of all members of such a huge dataset? The MMS standard (ISO 9506) does not have a parameter like "more  follows" or "continue after". Is there a possibility at the level IEC 61850-7-2?

One can use an IEC 61850 report control block, refer to the "big" data set and run the "general interrogation" issued by a client. The reporting model provides segmentation! It is - of course - optional. So the server and the client need to support segmentation.

The IEC 61850 report message has the following parameter:

MoreSegmentsFollow (More report segments with the same sequence number follow).

No comments: