Used (globally) for smart metering data exchange. Developed and maintained by the DLMS User Association (and also referred to as IEC 62056), the standard defines a set of interface classes or COSEM objects (Blue book) and supporting protocols (Green book).
Note: some parts of the world have different metering standards which use aspects/variants of DLMS (e.g. GBCS (UK), G3 PRIME etc.)
