UNITA' DI CONTROLLO DELLA SEGNALAZIONE DI TIPO MULTIFREQUENZA,DI PARTICOLARE APPLICAZIONE NELLE CENTRALI TELEFONICHEDI TRANSITO DI TIPO NUMERICO

A multifrequency signalling control unit UCSm comprises first and second frequency discriminators DF, each of which receives from the exchange connection network multifrequency code telephone control signals relating to 32 connections and detects the pair of frequencies utilized for each signal. First and second emitters IV each carry out conversion from 32 codes relating to telephone control signals into as many codes relating to the sum of the pair of characteristic frequencies of each telephone control signal which can be sent to the connection network RC. A level discriminator DL detects the "validity" of each pair of frequencies available at the output of the frequency discriminators DF, a processor EL sends the telephone control signals detected by the level discriminator DL to the central control unit CC and sends the telephone control signals to be transmitted by way of the connection network RC to the emitters IV.