Paragraph: Table 42 – Mapping of GetDataValues service parame
Category: Issue for edition 2 of this part
Issue
The Service GetDataValues is defined in IEC 61850-7-2 Ed2
11.4.2.1 GetDataValues parameter table
A client shall use the GetDataValues service to retrieve values of data attributes of the referenced data objectS [plural !!] made visible and thus accessible to the requesting client by the referenced logical node.
The syntax of the table has only a single Reference (to a single object; either FCD or FCDA) as a parameter.
The mapping in IEc 61850-8-1 Ed2 defines in 13.4.1 GetDataValues the mapping of a single Reference to the MMS variableAccessSpecification.
The UCAIUG Test procedure requires in test case Srv7:
Test description : 1. Client requests one GetDataValues with multiple data objects.
There is no definition in 7-2 or 8-1 that multiple FCD's or FCDA's could be read (or written). MMS supports it.
Proposal
Add the following text after Table 42 – Mapping of GetDataValues service parameters:
The variableAccessSpecification shall allow to specify one or more References. Note: This allows to read multiple MMS NamedVariables in one MMS Read message.
Add the following text after Table 43 – Mapping of SetDataValues service parameters:
The variableAccessSpecification shall allow to specify one or more References. Note: This allows to write to multiple MMS NamedVariables in one MMS Read message.
Discussion
Created
Status
12 Apr 13
In Force (green)
The rstriction to one FCD or FCDA in 7-2 and to one NamedVariable in 8-1 (MMS) should be defined as the only solution. A read and write message (in 8-1, MMS) shall not be allowed to access two NamedVariable in one message.
This should be very clearly defined in 7-2 and 8-1.
Add the following (modified) text after Table 42 in 8-1 – Mapping of GetDataValues service parameters:
The variableAccessSpecification shall allow to specify one Reference only. Note: This allows to read a single MMS NamedVariables in one MMS Read message.
Add the following (modified) text after Table 43 in 8-1 – Mapping of SetDataValues service parameters:
The variableAccessSpecification shall allow to specify one Reference only. Note: This allows to write to a single MMS NamedVariables in one MMS Read message.
13 Aug 12
Ballot Period
not accepted.
No change required in 8-1.
The standard (7-2, and therefore 8-1) does not specify a reaction for more than one reference in the read / write request.
09 Aug 12
Ballot Period
We can not only restrict this, we have already done this in Edition 1. There is no need to introduce more interoperability problems.
12 Jul 12
Discussion (red)
8-1 represent exactly what has been written in 7-2: single read. The paramter specifies a single reference in 7-2, so does it in 8-1.
The PIXIT could be extended, or the UCA Test procedure modified.
So far I would agree with Christoph:
Even if MMS supports reading of multiple objects, we can still restrict the implementations to read only one object at a time.
25 Jun 12
Discussion (red)
If we modify this in the mapping, I assume we then need as well to modify it in Part 7-2.
Even if MMS supports reading of multiple objects, we can still restrict the implementations to read only one object at a time. Is the extension really needed?