Created: 08 May 2014
Status: In Force (green)
Part: Part 6 (2009-12; Edition 2)
Category: Issue for edition 3 of this part
Part 6, Clause 9.3.13, explicitly allows only two forms of ExtRef elements:
1) Full (resolvable) reference to the input signal(s), (i.e., iedName, ldInst, prefix if there is one, lnClass, lnInst, doName and daName, which can be omitted in case of an FCD), optionally intAddr, desc, serviceType and reference to the sending control block.
2) Just the intAddr and optionally desc and serviceType, typically in the ICD file case. The desc would contain human-readable information that will help the IED engineer "connect" the input signals.
I propose to add a 3rd case, also for ICD/IID files (or partially engineered SCD), where one could add more semantic information about the input signal(s): to have just LN class, DO name, DA name, intAddr, and optionally desc and serviceType
The reference to the signal would be only partial (no or optional iedName, ldInst, prefix, and lnInst) and describe only the semantics. This way, tools can help do the mapping of input signals to internal signals and help detect inconsistencies/errors.
Of course, during engineering this information might be replaced (e.g., use a XCBR.Pos.stVal instead of a CSWI.Pos.stVal).
Describe this additional case in Part 6.