The standard applies to the ACSI communication in substations and feeder applications. The ACSI provides the following abstract interfaces. Abstract interface describing communications between a client and a remote server for real-time data access and retrieval, device control, event reporting and logging, publisher/subscriber, self-description of devices (device data dictionary), data typing and discovery of data types, and file transfer. Abstract interface for fast and reliable system-wide event distribution between an application in one device and many remote applications in different devices (publisher/subscriber) and for transmission of sampled measured values (publisher/subscriber). This part of IEC 61850 may also be applied to describe device models and functions for additional activities, such as substation to substation information exchange, substation to control centre information exchange, power plant to control centre information exchange, information exchange for distributed generation, or information exchange for metering.