10
The ANSI C12 Suite
10.1 Introduction
Before the publication of C12, meters from different vendors in the USA did not use the same data formats or communication protocols. C12 is a standard suite specified by the American National Standards Institute (ANSI), which provides an interoperable solution for data formats, data structures, and communication protocols used in automatic metering infrastructure (AMI) projects. Although this standard is focused on the American national market, C.12 is used in smart metering systems of many countries (in particular its variant OSGP, deployed by Echelon, Inc).
The standard data structure is specified in the ANSI C12.19 document. It is defined as a set of tables. When these tables share a common purpose or they are relative to a common feature of the meter, then the tables are included in a specific chapter called a “decade”.
The first communication protocol that made use of the C12.19 tables was specified in the ANSI C12.18 document. The first release was published in 1996 and describes the communications between a C12.18 meter and a C12.18 client by means of an optical port. A C12.18 client could be a hand-held reader, a laptop, or any device with an optical port.
In 1999, ANSI C12.21 was specified for communications between a C12 device and C12 client via a modem. This offered a first solution for AMI projects.
In 2007, a new specification took into account the development of data networks not using modems. ...
