07-2 DLMS/COSEM over PLC - a hot item
Smart metering for residential customers, driven by market liberalization, regulatory changes, technology advancements and its potential to better control end eventually help reducing energy consumption through better information to customers, is high on the Agenda of metering people worldwide. Power Line Carrier (PLC) lends itself as the number one media for this purpose. This is the reason why, after the article appearing in Q4/2006 of Metering International we return to the subject.
Since then, we have received strong market signals from all over the world, from actual and potential members of the DLMS UA that DLMS/COSEM is seen as a suitable platform for standards for this new generation of meters, ensuring interoperability, a must for large-scale rollouts and for enabling competition.
Responding to this need, the DLMS UA decided to add new communication profiles for PLC, with a view of offering the result for international standardization to the IEC, using a fast track mechanism. A project team consisting of experts from leading meter manufacturers and some large utilities with a rich experience in using PLC has been set up and met already three times this year.
The project builds on the results of the work of IEC TC 57, having developed the IEC 61334 series of PLC standards and that of IEC TC 13 having developed the IEC 62056 DLMS/COSEM standards.
The IEC 61334 series specifies a number of lower layer PLC profiles, covering the physical and MAC layers of the OSI model. Since their publication at the beginning of this decade, they have been proven on the field over and over. The upper layers of the protocol stack, including the Logical Link Control layer and the Application layer based on DLMS, are common for all lower layers.
Although IEC 61334-4-42, the DLMS standard specifies a general purpose object model, the COSEM object model, developed for energy metering and specified in IEC 62056-62, is much more suitable to model the required functionality of smart meters. The COSEM object model has proven to be successful already in millions of electricity meters installed for industrial and commercial customers.
Therefore, the project team decided to merge the strong points of the two sets, taking the COSEM object model with the OBIS identification system as well as the COSEM Application layer from the IEC 62056 series, and taking the PLC media specific lower layers from the IEC 61334 series. The main points have been agreed on. Drafting of the standards has been started and IEC standardization work should be launched in the second half of this year.
This activity creates a lot of interest worldwide. With several companies applying for membership and participation in the Project Team, the membership of the DLMS UA approaches a 100 now.
Obviously, the Conformance Test Tool will be extended to cover this new communication profile. To date, 60 meter types have been certified to be “DLM/COSEM compliant” and we expect many more in the near future.