| 摘要 |
PURPOSE:To discriminate the start time point for transmission of a voice message by defining a digital code which is not used to the voice message as a lead-out code and adding this lead-out code to the head of the message for transmission of the message through the same message channel. CONSTITUTION:When a subscriber 6 gives a call to a talking trunk 21 to listen to a voice message, the ringing tones are sent back to the subscriber 6 from a ringing tone generating circuit 214. While a serial/parallel conversion circuit 215 converts a lead-out code H and a digital message code train M sent from a message output device 100 into parallel codes. While a lead-out data generating circuit 216 produces the code H and transmits it to a comparator 217. The comparator 217 compares a digital code with the code H and supplies the logic '1' to an FF21 when the coincidence is obtained between both codes. As a result, '1' is delivered through a gate 212 and a selector 213 connects a message line 4 to a channel 12. Then the code train M is sent back to the subscriber 6 from the device 100 via the selector 213, the channel 12 and a switchboard 3. |
