DLMS or Device Language Message Specification, is the suite of standards developed and maintained by the DLMS User Association and has been adopted by the IEC TC13 WG14 into the IEC 62056 series of standards. COSEM or Companion Specification for Energy Metering, includes a set of specifications that defines the Transport and Application Layers of the DLMS protocol.

The DLMS User Association defines the protocols into a set of four specification documents namely Green Book, Yellow Book, Blue Book and White Book. The Blue book describes the COSEM meter object model and the OBIS object identification system, the Green book describes the Architecture and Protocols, the Yellow book treats all the questions concerning conformance testing, the White book contains the glossary of terms. If a product passes the Conformance Test specified in the Yellow book, then a Certification of DLMS/COSEM compliance is issued by the DLMS UA. 

The relevant IEC standards are as follows:

  • IEC 62056-1-0:2014 Smart metering standardisation framework
  • IEC 62056-3-1:2013 Use of local area networks on twisted pair with carrier signalling
  • IEC 62056-5-3:2016 DLMS/COSEM application layer
  • IEC 62056-6-1:2015 Object Identification System (OBIS)
  • IEC 62056-6-2:2016 COSEM interface classes
  • IEC 62056-7-6:2013 The 3-layer, connection-oriented HDLC based communication profile
  • IEC 62056-8-3:2013 Communication profile for PLC S-FSK neighbourhood networks
  • IEC 62056-9-7:2013 Communication profile for TCP-UDP/IP networks

source: https://en.wikipedia.org/wiki/IEC_62056



Automatic Meter Reading, or more general - Demand Side Management - needs universal definitions, needs communication standards. DLMS/COSEM is the common language so that the partners can understand each other. source: http://www.dlms.com

Being an object-oriented open international standard, DLMS/COSEM is the de-factor AMR standard in most part of the world. It is well organized and facilitates the interoperability among devices and systems from different vendors. The DLMS/COSEM standard offers compliance testing tools to verify the compliance of meters. 


Microstar & DLMS/COSEM

As a member of the DLMS UA, Microstar is among the first companies in the world to supply DLMS compliant meters. Microstar and its research facility Bluestar Meter Research Institute have been an advocate for the adoption of  DLMS/COSEM standard for its merits. Microstar/Bluestar has also offered DLMS compliance testing service to other meter manufacturers. 

The full line of Microstar smart meters comply with the DLMS/COSEM standards (certified). Microstar's TMR-2012 AMI system also supports integration of meters based on DLMS/COSEM standards.