This part of ISO 17458 specifies the conformance test for the electrical physical layer of the FlexRay communications system. This part of ISO 17458 defines a test that considers ISO 9646 and ISO 17458-4. The purpose of this part of ISO 17458 is to provide a standardized way to verify whether FlexRay Bus Driver and Active Star products are compliant to ISO 17458-4. The primary motivation is to ensure a level of interoperability of FlexRay Bus Drivers and Active Stars from different sources in a system environment. This part of ISO 17458 provides all necessary technical information to ensure that test results will be identical even on different test systems, provided that the particular test suite and the test system are compliant to the content of this part of ISO 17458.