It's not unambigeously defined how to engineer the SCL and how toinstantiate it for operable control objects (like DPC). Related paragraphs are:
- Part 6 table 44 fc attribute
- Part 7-3 par 7.5.3 DPC
- part 8 Annex E.1 Note
- part 8 Annex E.2 last sentence on page 121
- part 8 annex E.3.2 DPS table E.3 "inherited data attributes"
The first issue is: should the SCL include the Oper, SBOw and Cancel objects? When not the SCL does define the applicable Oper/SBOw/Cancel structure (in which the OperTm is optional). When yes changing the ctlModel value, will result in removing/deleting Oper/SBOw/SBO/Cancel attributes.
The next issue is: should the SCL contain the ctlVal? According to Annex E.2 all CO attributes from 7.3 are replaced by the new CO definitons in Annex E. But annex E.1 Note states: "no CDC attributes haven been deleted".
The last issues is: should the optional ST$origin also instantiate the CO$origin? This is very cryptic defined in part 6 tabel 44. Or is clear that part 8-1 already "imply" the CO instantiation? Part 8-1 table E3 states the CO will not be inherited/instantiated.
Please clarify for each issue which options are allowed. When more options are allowed for a issue please clarify how the SCL reading tools/systems are able to differentiate which option is used.
I propose to include one or more SCL examples in Annex E: