This document specifies the representation of Alarms and Conditions in the OPC Unified Architecture. Included is the Information Model representation of Alarms and Conditions in the OPC UA address space. Other aspects of alarm systems like alarm philosophy, life cycle, alarm response times, alarm types and many other details are captured in standards such as IEC 62682 and ISA 18.2. The Alarms and Conditions Information Model in this specification, is designed in accordance with IEC 62682 and ISA 18.2. Annex C specifies how the model described in this document maps to EEMUA. Annex D specifies a recommended mapping between OPC Classic Alarm & Events (A&E) servers to the model described in this document.