"The IEC 61970-405 Generic Eventing and Subscription (GES) specification specifies a generalized interface for efficient exchange of messages. The specification takes into account the latencies caused by a Local Area Network (LAN) providing efficient data exchange also over Local Area Networks. The Generic Eventing and Subscription (GES) API is expected to provide one of the primary means for accomplishing application integration. Beyond the scope of the GES API@ other APIs address the high performance@ real-time interactive needs of an application within a running system as well as request eply oriented generic data access. IEC 61970-405 is derived from the Object Management Group (OMG) Data Acquisition from Industrial Systems section Alarms and Events (DAIS AE) specification. OMG DAIS AE relies on the OMG Data Access Facility (DAF) and OPC Alarms and Events (AE) specifications. OMG DAIS AE is a Platform Specific Model (PSM) with CORBA as the platform and OPC AE is a PSM with Microsoft COM as the platform. Implementers wanting an introduction to OMG DAIS AE and OPC AE shall read these documents. The GES interface is intended to interoperate with other IEC 61970 based interfaces. Hence it is possible to use information retrieved from other interface to access the same information using this interface@ for example: ? object identifiers@ ? attribute names or identifiers@ ? class names or identifiers. The way data is organized in a server implementing the GES interface can be seen by using the browse interfaces for data and meta data. It is also possible to use the data access interface directly without using the browse interfaces if the client has an a priori knowledge of object@ class and attribute identifiers. Object identifiers may be retrieved using data from other interfaces@ for example a CIMXML file or the IEC 61970-404 interface. Information on what classes and attributes are available will be described in IEC 61970-45X documents. IEC 61970-405 describes the functionality in a technology independent way@ it is a Platform Independent Specification (PIM). Hence@ it explains the functionality to a level that can be used to create PSMs or be an introduction to existing PSMs@ i.e. DAIS AE and OPC AE. Implementers wanting an introduction to OMG DAIS AE and OPC AE should read these documents. IEC 61970-405 consists of two parts: ? SCADA alarms and events that is the Platform Independent Specification (PIM) derived from DAIS AE and OPC AE. This part is called ""Generic Eventing and Subscription Alarms and Events"" (GES AE). ? Generic messaging that is a generalization of the SCADA alarms and events. This part is just called ""Generic Eventing and Subscription"" (GES). IEC 61970-1 provides the EMS-API reference model upon which this standard is based. In that reference model@ the terminology used in this part of IEC 61970 is introduced and the role of the CIS is explained. IEC 61970-401 provides an overview and framework for the CIS (IEC 61970-4XX) standards.IEC 61970-402 provides the base services to be used in conjunction with other IEC 61970-4XX documents. This specification extends the Common Services to provide an event subscription oriented mechanism for applications to exchange CIM data. The mapping of IEC 61970-405 to implementation specific technologies or Platform Specific Models (PSMs) is further described in a separate series of documents@ i.e. the future IEC 61970-5XX. For actual implementations@ the future IEC 61970-5XX@ OMG DAIS AE@ OMG DAF or OPC AE are used."