This International Standard is applicable to high-voltage switchgear and controlgear (scope of IEC SC 17A) and assemblies thereof (scope of IEC SC 17C) and specifies equipment for digital communication with other parts of the substation and its impact on testing. This equipment for digital communication@ replacing metal parallel wiring@ can be integrated into the high-voltage switchgear@ controlgear@ and assemblies thereof@ or can be an external equipment in order to provide compliance for existing switchgear and controlgear and assemblies thereof with the standards of the IEC 61850 series.This International Standard is a product standard based on the IEC 61850 series. It deals with all relevant aspects of switchgear and controlgear@ and assemblies thereof with a serial communication interface according to the IEC 61850 series. In particular it defines:a) A selection of the information models from the IEC 61850 series that shall be supported by such switchgear and controlgear@ and assemblies thereof.b) Conformance classes for the set of communication services that shall be supported by the switchgear and controlgear@ and assemblies thereof.c) Modifications and extensions to type and routine tests of switchgear and controlgear@ and assemblies thereof that are required due to the serial communication interface.d) An extension of the IEC 61850 series?? object model for switchgear monitoring.NOTE 1 It is intended to integrate the extension of the IEC 61850 series?? object model for switchgear monitoring into a further revision of the IEC 61850 series. Once this integration is completed@ the relevant parts will be removed from this standard.The document is based on the IEC 61850 series@ the horizontal standard series for communication@ and specifies the requirements for digital communication equipment used within high-voltage switchgear@ controlgear@ and assemblies thereof@ as well as the relevant testing requirements.The relevant switchgear standards of the IEC 62271 series are applicable in general@ with the additional specifications described in this standard.NOTE 2 There is a limited activity today concerning switchgear with digital interface for rated voltage levels less than@ or equal to@ 52 kV. Such switchgear usually does not have integrated digital communication interfaces. If such products are to be developed@ this should be done in accordance with the present standard.NOTE 3 This standard intends to promote interoperability of communication interfaces. Interchangeability is outside the scope of this standard@ as there is no requirement for it. Interchangeability is also outside the scope of the IEC 61850 series.NOTE 4 For an introduction to substation communication and the related terms@ definitions and models@ refer to IEC 61850-1 which provides an overview of the objectives and requirements of the IEC 61850 series in general. IEC 61850-7-1 provides an overview of modelling techniques.