| 摘要 |
PURPOSE:To ensure the storage of the data terminal with no intervension of the analog data transmission MODEM by providing the conversion and its reverse conversion circuits between data 0 and 1 of the PCM code row and the digital data terminal for the analog data transmission MODEM to the digital telephone exchange. CONSTITUTION:The analog signal sent from data terminal DT-A connected to analog data MODEM M/D is turned into the digital PCM code via PCM modulator/ demodulator CODEC and then taken into time-division channel TDSW. At the same time, the data of digital transmission data terminal DT-D is connected to channel TDSW via digital data transmission control circuit DCES and by PCM code row transmission circuit DSND which converts the data of 0 and 1 into the specified PCM code series plus the contrary PCM code series reception circuit DRCV which converts the input PCM code series into the 0 and 1 patterns for the digital transmission respectively. Then the signal is processed via the signal processor SPR, and the exchange connection is given by the indication of central processor CP. |
