| 摘要 |
PURPOSE:To improve the transmission efficiency of data by always setting a carrier detecting signal to an ON state, when no MODEM is necessitated, inserting packet data into an unnecessary control signal bit from a terminal in accordance therewith and transmitting it. CONSTITUTION:When no MODEM is interposed between a multiplexing transmission device and a terminal, a carrier detecting signal CD is always set to an ON state by a setting part 4. Subsequently, in a packet data inserting part 3, packet data is inserted into a bit position of a control signal from the terminal and a control signal RS in a multiplexing signal containing data or packet data and inputted to a selector 5. Next, by the carrier detecting signal CD which always shows ON, an output of the packet inserting part 3 is selected in the selector 5 and sent to a multiplexing part 2, multiplexed with an output signal from a selecting part 1 and transmitted. In such a way, when no control signal is necessitated, the packet data is inserted into its bit position, therefore, the circuit efficiency can be enhanced. |
