A multimode physical layer circuit for physical layer handling of signals transported over a high-definition multimedia interface cable in a home multimedia network, wherein the signals are compliant with at least two different PHY layer modes. Then, a trap circuit for removing the high frequency signal is provided on an in-building upward signal path in each converter. Furthermore, single side emitting and double side emitting OLEDs can be used in combination with the socket. A testing interface on an external portion of the instrument housing and a testing module can be used to perform tests on the instrument. The openings 113, 114 and the passage within the arm 112 are of suitable dimensions to carry a cable 105.