IEC 62026-2:2008+A1:2019 specifies a method for communication between a single control device and switching elements, and establishes a system for the interoperability of components with the specified communication interfaces. The complete system is called "Actuator Sensor interface (AS-i)". This second edition of IEC 62026-2 cancels and replaces the first edition published in 2000. It constitutes a technical revision. The main changes with respect to the previous edition are listed below: doubling the number of slaves from 31 to 62 by introduction of sub-addresses; introduction of AS-I safety system. This consolidated version consists of the second edition (2008) and its amendment 1 (2019). Therefore, no need to order amendment in addition to this publication.