Open metering system
The open metering system OMS stands for a manufacturer- and utilities-independent standardization for Meter-Bus (M-Bus) based communication between utility meters (electricity, gas, water, district heat, heat cost allocators) and systems in the field of smart meters.
With the starting point of the smart metering initiative driven by the European Union, several German multi utilities companies (public utility offering more than only one type of supply like electricity, gas, water and district heat) joined and asked international manufacturers of revenue meters to create a common standard. The goal was to have meters with standardized communication interfaces and systems in the future. On the side of meter manufacturers there were mainly the members of the technical associations in Germany FIGAWA (German Association for Gas and Water) and ZVEI (German Electrical and Electronics Industry Association), but also several other internationally operating companies joined to create a bundle of common definitions and specifications based on the European Meter-Bus standard (EN 13757) as well as the Dutch NTA 8130.
Concerning the created Open Metering System Specification (OMS specification or OMSS) a subset out of the existing Meter-Bus standard series (EN 13757) was selected, definitions were made where selections or ambiguities were possible, to streamline the interpretation by different producers. In addition the encryption using the AES 128 standard has been introduced as a requirement for all wireless and Power-line communication based communication channels.
The outcoming results were entered in the European standardization organization and is currently being discussed as an adoption or extension of EN 13757. The OMS specification documents are in English and available for free.