1964   Which value to be used to mark invalid data in backwards compatibility

Created: 13 Feb 2025

Status: Discussion (red)

Part: Part 9-2 (2020; Edition 2.1)

Links:

Page: 13

Clause: 8.6

Paragraph: Table 21

Issue

Table 21 allows both values "01" and "10" to mark invalid data quality. Foot note 1 explains that "The reserved value has been redefined to "invalid" for backward compatibility."

C.3.5: This revision of IEC 61850-9-2 modifies the mapping of quality for backward compatibility with existing servers. ”Reserved” value shall now be interpreted by clients as “Invalid”.
Servers compliant with the current document shall not use the formerly “Reserved” value".


Existing publishers can publish invalid SV data using the “10” value.
Existing subscribers expect to receive invalid data marked with "10”.

Does an up-to-date SV publisher running in compatibility mode has to use “10” to mark invalid data?

Proposal

Please define whether an up-to-date SV publisher running in compatibility mode has to use “10” to mark invalid data.