00-1 IEC Standards on the go!
The Books evolve ...
As explained in earlier issues of Metering International (e.g. 1999-2), the DLMS User Association defined its findings in "coloured books" which form technical reports on COSEM, the companion specification for energy metering. The Orange Book handles the description of the object identification system OBIS. Not only general purpose objects (e.g. "energy register" or "number of days since last reset"), but also abstract objects (e.g. of class "association") are described. The structured description of application items translates to a number, which is nothing else but the object name, applied to an object of the Blue Book. This book contains exact descriptions of the functionality of meters, be it a quite complex meter for commercial and industrial usage or simpler meters for residential use. These descriptions are called "Interface Objects".
The Standards
The members of the DLMS User Association have been active in the meantime. They initiated activities in standardisation bodies, this time in IEC TC13, the Technical Committee which establishes standards for "equipment for electrical energy measurement and load control", e.g. electricity meters. Its Working Group 14 handling "data exchange for meter reading, tariff and load control" reached a milestone in their work program, as they sent the documents "Interface Objects" and "OBIS Object Identification System" to IEC Headquarter in Geneva, which puts these documents on the table of National IEC Committees world-wide. These committees will have to vote on the documents which are called CDVs. In case of a positive vote, the document will be published as FDIS (Final Draft International Standard) in the second half of the year 2000. These documents will then help to build up the library of DLMS oriented standards. Let us remember that the first DLMS standard (IEC 61334-4-41) was released in 1996 by IEC TC57, which establishes standards for "power system control and associated communications".
While the voting period goes on, there will be no standstill in the DLMS UA and in IEC TC13 WG14. The channel oriented documents will also reach CDV stage, which means that the Physical Layer, the Data Link Layer and the Application Layer will also be defined. They will carry the above described interface objects and allow to build up a system which is able to cope with the challenges of the liberalised market and the requirements for energy trading.