1950 Clarification needed about the diwngrading of an ICD to a lower edition in the IID

Created
15 Nov 2024
Status
TriageNew, and not yet classified. The working group decides whether to take it forward as a technical issue or to close it. Show the workflow
Part
Part 4 (2011; Edition 2)
Links
None
Page
29
Clause
6.4
Paragraph
general

Issue

During IOP 2024, there was a ICT providing an IID in SCL ed2.0 but the ICD was in SCL 2.1.

Is it allowed to downgrade an IED already integrated in a system?

Need to clarify the case

Proposal

It is not recommended to let the standard supporting this usecase because some of evolution related to newer edition may have been already used in the system, and downgrade by mean of an IID may break the configured system.

In this case the user have to reconfigure the device completely to integrate new limitation following downgrade of the device.

DiscussionCreated
Triage During the engineering of a project, I agree, it does not make sense to use older SCL version files for IID file over time. The original scl should not decrease. However, for the sake of evolution of project, what prevent to upgrade the upgrade originalScl to never version when a new ICT release provides IID files with newer SCL version?
09 Dec 24
Triage The observed behavior was done on purpose by the ICT, because the IED was configured as compliant to SCL ed2.0 even if originally it is SCL ed2.1. Only ed2.1 ICD is available and the ICT do the downgrade in the IID.

When an IED is already integrated in a system, an edition change of this IED (downgrade or upgrade) will potentially trigger incompatibility in the system with other device.

It should be forbidden to change the edition of an already engineered device it it shall go throw a replacement of the device (which can be done also with the new IID, but the dataflow will not be expected to be kept).

This process is not clear and shall be described in part 4, to not let users imagine that the IED will be kept with exactly the same configuration after the replacement
03 Dec 24
Triage When you downgrade an SCD file (IED integrated in a system), you downgrade the entire SCD file, including all IEDs.
29 Nov 24
Triage Maybe this is an ICT implementation error?
SCD is required to import [either] ICD or IID.
This device advertised 2 different SCL versions depending upon whether the ICT exported the ICD or IID and this should NOT be allowed.

or maybe the device was actually upgraded from 2.0 to 2.1 and it is a user error to attempt to import a different version of SCL than the one that exists in the SCD file (an efficient SCT should flag this error).
In this case, the user should first use the SCT to remove the [now obsolete] device then re-insert it at the upgraded version.
15 Nov 24