| 摘要 |
<p>PROBLEM TO BE SOLVED: To make respective telephone systems simple and inexpensive by synchronous/ asynchronous converting synchronous transmission data, transmitting them as start-stop synchronous transmission data, asynchronous/synchronous converting start-stop synchronous reception data and turning them to synchronous reception data. SOLUTION: Analog voice signals from the extension telephone of this telephone system 1A are converted into PCM data in a corresponding codec 5-1, time-divided by a time division switch 6 and supplied through a speech path 7 to a synchronous/ asynchronous conversion part 12 as the synchronous transmission data. They are converted into asynchronous transmission data with a burst property there and supplied to a start-stop synchronization interface 11. In the interface 11, start and stop bits are added to the asynchronous transmission data from the conversion part 12 and they are converted into the start-stop synchronous transmission data and sent out to the telephone system 1B. Reception data from the system 1B are converted in an asynchronous/synchronous conversion part 13, time-divided by the switch 6, supplied through the speech path 7 to the codec 5-1, converted into the analog signals and supplied to the extension telephone set.</p> |
