Descriere:

The invention relates to a method and an apparatus for tesing the validity of wire pairing in bunched cables used in communications. According to the invention, the method involves the following stages for each cable: a stage of checking the static pairing of wires, when each tested pair forms a closed loop, by the serial connection with a diode-resistor group successively connected to certain preset potentials, then measuring the potential of the excited pair and the potentials of the other wires of the cable, compared then with some previously calculated values; a stage of calibrating the measuring instrument of the apparatus for each pair of the cable, comprising two steps, one step for measuring the bottoming voltage in the pair, and the second step for measuring the integral of a standard test sequence of positive rectangular pulses, followed by the same sequence in reversed phase; a stage of checking the dynamic pairing validity, when the pairs of the cable are divided into three classes, a first class including a single active pair by injecting the standard test signal into the first wire and a reversed phase signal into the other wire, the second class also including a pair of wires, one of which is connected to a fixed potential (V0), while the potential of the other wire is filtered, integrated, measured, and the result is memorized, all the other passive pairs of the cable connected to a fixed potential (VF) forming the third class. The claimed apparatus comprises a control and computing unit (UC), a controlled multiplexer (UMUX), some resistors (RA, RB, RC, RD, RE, RF), a final circuit comprising some serially connected diodes and resistors (R1, D1, R2, D2, R3, D3, R4, D4), some filtering circuits and an integration circuit, connected according to the claimed method by means of some controlled contacts (k1, k2, k3), an operational amplifier, a digital-to-analogue converter (CAN) and a viewing and interface unit (UVI).