Saturday, July 14, 2018

IEC TC 57 just published FDIS IEC 61850-8-2 (Mapping to XMPP)

IEC TC 57 just published FDIS IEC 61850-8-2 (Mapping to XMPP) - 253 pages !


Voting ends: 2018-08-24

Part 8-2: Specific communication service mapping (SCSM)
– Mapping to Extensible Messaging Presence Protocol (XMPP)

The long wait for a second SCSM is over!

The new mapping of IEC 61850 describes a specific communication service mapping
(SCSM) over the Extensible Messaging and Presence Protocol (XMPP), providing detailed
information on how to create and exchange concrete communication messages that
implement abstract services and models specified in IEC 61850-7-4, IEC 61850-7-3, and
IEC 61850-7-2.

Note that the MMS messages (defined using ASN.1) are used in IEC 61850-8-1 AND -8-2 ! The only crucial difference between the two message and model mappings (in 8-1 and 8-2) is this:

8-1 uses BER (Basic Encoding Rule) for the messages on the wire, while 8-2 uses (XER (XML Encoding Rule). The complexity of the MMS messages is the same in both mappings - because the structure and how to build messages and how to carry the 7-2 services and 7-x models are the same!

The challenges to implement 8-2 message mapping are more or less the same as with 8-1. Note that the messages in XER are far longer than with BER.

There is - of course - a difference between the two: The transport of messages in 8-2 uses XMPP.

Some may argue, that there are more tools available for XER than for BER. Ok.

IEC 61850-8-2 is far away from something simple and easy to implement and use - especially when you need only a few simple services and models.

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