This Standard applies to emission and immunity aspects of EMC for electrical and electronicapparatus intended for use on railway rolling stock. EN 50121-3-2 applies for the integration ofapparatus on rolling stock.The frequency range considered is from d.c. to 400 GHz. No measurements need to be performed atfrequencies where no requirement is specified.The application of tests shall depend on the particular apparatus, its configuration, its ports, itstechnology and its operating conditions.This standard takes into account the internal environment of the railway rolling stock and the externalenvironment of the railway, and interference to the apparatus from