1723   There is no mechanism to configure an Edition 2.1 SV Control Block to publish an Edition 2 or Editio

Created: 10 Oct 2020

Status: Not Applicable

Part: Part 6 (2019; Edition 2.1)

Links:

Page: 108

Clause: 9.4.5

Paragraph: Table 40

Issue

IEC 61850-9-2 Edition 1 did not require subscriber parsers to ignore unknown fields. In Edition 2, an optional SmpMod value was added to the ASDU production. Edition 2 did not required subscriber parsers to ignore unknown fields. Edition 2.1 added a condition SynchSrcID to the ASDU production.

If the SmpMod or SynchSrcID attribute is present in the ASDU, an IEC 61850-9-2 Edition 1 subscriber will not be able to consume this PDU, therefore it is a backward compatibility issue.

If SynchSrcID attribute is present in the ASDU, an IEC 61850-9-2 Edition 2 subscriber will not be able to consume this PDU, therefore it is a backward compatibility issue.

The Edition 2.1 ASDU production does have a mandatory capability to ignore unknown ASDU additions.

There needs to be a SCL configuration option to allow a SV Control block to be configured to publish Edition 1 or Edition 2 compatible ASDUs.

Proposal

Add a backwardCompatibiliity Boolean to the tSMV definition. The default should be false. The value of true should be defined such that the publisher sends an Edition 1 compatible ASDU (e.g. no SmpMod or SynchSrcID.