Patent ID: 6169784
Filing Date: 2001-01-02
Classification: H04M

Abstract:
An apparatus for determining an impedance between two wires of a 2-wire connection connected between a subscriber line interface circuit (SLIC) and a subscriber circuit, the apparatus comprising a connection from a telephone exchange to the subscriber circuit, the connection being made via the SLIC and a termination box; the termination box having a capacitor and a resistor connected in series between the two wires of the 2-wire connection and the termination box being located between the SLIC and the subscriber circuit; the SLIC including a switch for disconnecting one wire of the 2-wire connection and a further switch connected to the one wire and a SLIC supply rail and having a current monitor point in series therewith, wherein the time required to discharge the capacitor may be monitored enabling determination of the impedance between the two wires of the 2-wire connection.