ISO 21806-2:2020

This document specifies a part of the application, the application layer, and the presentation layer.
The application covers the
- device model,
- registry management,
- connection management for streaming data,
- diagnosis, and
- error handling.
The application layer covers the structure of MOST messages consisting of
- addressing,
- function block identifiers,
- instance identifiers,
- function identifiers,
- operation types, and
- timing definitions.
The presentation layer covers the definition of data, basic data types and function classes.