valkind=RO has typically been defined as restricting the ability to change a value online. Valimport was defined to address this same semantic for SCL based configuration. However, tissue 804 defines a relationship between the online restriction and the scl restriction to indicate that a System Configuration can't change a value (e.g. the value is fixed).
The reason for this proposal was the unknown behavior of Edition 1 SCL exchanges.
Need to base the behavior of valimport on SCL version and not a relationship to valkind.
Proposal
Propose to re-write the valimport text to be:
For SCL version 2003, valkind=false indicates that the SCT/SCD may attempt to modify the value provided by the ICT. However, it is not guaranteed that the SCT provided configuration value will be accepted by the ICT/IED.
For SCL versions of 2007, or newer, the valimport=false shall indicate that the SCT shall not attempt to change the value and any such change shall be ignored by the ICT/IED.
For any SCL version, valimport=true indicates that the SCT can change the configuration value and the ICT/IED shall accept that value if the value validates as an acceptable value.
Discussion
Created
Status
In principle accepted. See revised solution text in Tissue 804.
18 Jun 15
Not Applicable
Modify proposal for SCL version 2003: Version 2003 forbids use of "valImport". Behavior as stated in proposal is correct. Upon import of a version 2003 ICD (SCL element not containing a version attribute means Ed.1), the SCT shall assume that valImport=false for all IEC 61850 data attributes and operate according to the proposal.
Furthermore, SCT shall be prohibited from modifying Data Attributes which have been imported with "SCL@version" (Ed.2 and newer) attributes which do not specify valImport="true".
15 Jun 15
Not Applicable
Not accepted. In SCL version 2003 there exists no valImport attribute. As edition 1 does not say anything about value import, for an edition 1 SCL description it should be clear that it is not known that a value from the system tool can be imported by the IED tool. From an Edition 2 system tool side it is save to assume that import is not possible; it is up to the system engineer to know better.
Further 804 does not define a relation ship. Still valKind relates to online services, and valImport to IED tool capabilities. It just says that from an engineering process perspective the combination valImport=false / valKind=RO reaches the goal that the value is neither automatically changed at SCD import nor online changeable, i.e. practically 'fix'. It is still the responsibility of the IED engineer to not (manually with IED tool) modify values defined in some standard if he wants conformance to this standard.