JPS5457811A - Analog switching system on digital link system - Google Patents

Abstract

PURPOSE:To miniaturize a switchboard by the use of a digital link. CONSTITUTION:This system is equipped with D/A converter 1, interface circuits 2, 3 and 5, A/D converter 4, terminal-assignment-information generating circuit 6, RT-relay-state detection circuit 7, L-relay-state detection circuit 8, arithmetic processing circuit 9, buffer register memory 10, terminal assignment circuit 11, answer detection circuit 12, calling detection circuit 13, dial receiver circuit 14, No.-''0'' called-subscriber assignment information memory 15, No.-''0'' subscriber's-transmission-signal digital memory 16, memory write decoder 17, sound-reduction-data generating circuit 18, memory read decoder 19, No.-''0'' called-subscriber assignment infromation memory 20, and No.-''n'' subscriber's transmission-signal digital memory 21. An analog signal equivlent to a subscriber is mixed and sampled and its subtraction is done by the digital information of the previously mixed analog signal. Subscriber's mixed transmission signal is stored temporarily as digital information, the result through the mixing method of a party subscriber is mixed, and the transmission signal of the party subscriber is obtained through the subtraction mentioned above and stored temporarily, thereby exchanging the pieces of temporarily-stored information each other.