| 摘要 |
PURPOSE:To use a pair of coding parts and decoding parts for time division to plural analog circuits and to improve economical efficiency widely by converting to a digital code after signals arriving from various analog channels are given time-division and duplexing treatment of analog signals. CONSTITUTION:An analog signal arriving from a two-wire system analog circuit 1 of a m circuit is a signal which successively is given time-division (m) and duplexing for every time area designated by selecting control signals Ta and Tam through a two-wire four-wire system converting part 2 at a selecting part 9, and transferred through circumferential part 10 to a coding part 11. The coding part 11 converts to a digital code and sends to an ascending digital highway 13 as a digital signal is given time-division (m) and duplexing treatment. On the other hand, the digital signal arriving from a descending digital highway 14 which is given time-division (m) and duplexing treatment, is converted to the analog signal at a decoding part 15 and transferred through a circumferential part 16 to a distributing part 17 as the analog signal which is given time-division (m) and duplexing treatment. The distributing pat 17 sends the analog signal successively extracted for every time area designated by the selecting control signal through respective two-wire and four-wire converting parts 2 to a two-wire system analog circuit 1. |
