This part of IEC60512 specifies the test methods for transmission performance for M12-style connectors up to 500MHz. It is also suitable for testing lower frequency connectors if they meet the requirements of the detail specifications and of this standard. NOTE1 All figures show equipment for connectors according to IEC61076‑2‑109 as an example. The test methods provided herein are: insertion loss, test 29a; return loss, test 29b; near-end crosstalk (NEXT) test 29c; far-end crosstalk (FEXT), test 29d; transverse conversion loss (TCL), test 29f; transverse conversion transfer loss (TCTL), test 29g. For the transfer impedance (ZT) test, see IEC60512‑26‑100, test 26e. For the coupling attenuation see ISO/IEC11801 . All test methods apply for two and four pair connectors. NOTE2 All figures show schemes for four pair cabling and are also suitable for two pair cabling.