First: The communication capabilities of a logical node are specified in the common logical node class (in the last six lines of the table in clause 5.3.3). This table is incomplete: the Log model is not listed here.
Second: The relation between the Data in the LN classes in 7-4 and the services defined for the Data class (common data class) in 7-2 (7-3) is not mentioned in 7-4. The intended interpretation is this: the services defined for the data class (common data class) shall be
applied! But this is not defined in 7-4.
This has already let to the following situation: a vendor implementing 7-4 (with a proprietary mapping) claims conformance with IEC 61850 !! (conformant to IEC 61850-7-4).
7-4 should define that:
a) The ACSI services for data as specified in 7-3 for the corresponding CDCs shall be applied for all compatible data defined in 7-4.
b) One of the existing SCSM shall be provided for the communication with the LN and data classes defined in 7-4.
Proposal
First:
Add two new lines before the line "Services (see IEC 61850-7-2)" in the table for the common logical node class:
Log (see IEC 61850-7-2)
(Inherited and specialised from Logical Node class (see IEC 61850-7-2)
Second:
Add text in 7-4 (may be under 5.2):
a) The ACSI services for data as specified in 7-3 for the corresponding CDCs shall be applied for all compatible data defined in 7-4.
b) One of the existing SCSM shall be provided for the communication with the LN and data classes defined in 7-4.
Discussion
Created
Status
Balloting time over
23 Mar 07
In Force (green)
The inheritance of services acc. 7-2 is given.
The question of existing SCSM is outside of part 7-4, but not outside of the scope of IEC61850. Shall be discussed in WG10.
11 Dec 06
Ballot Period
To make references to the services is principally accepted. Formulation has to be discussed. Details like the log model or SCSM are outside the scope of part 7-4.