| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the reliability in high speed data communication by reducing pulse distortion of data communication by an asynchronous transmission system. SOLUTION: A control unit 1 is connected to control units 2, 3 via an exchange 4 and transmission lines 5. The control unit 1 is provided with tow crystal oscillators 1a, 1b to generate a clock pulse and a changeover switch 1c to switch either of the crystal oscillators 1a, 1b in matching with a clock pulse of an opposite station, and the control unit 2, 3 is provided with a crystal oscillator 2a, 3a. The oscillating frequency of the crystal oscillators 1a, 2a and the crystal oscillators 1b, 3a is selected the same respectively, and in the case of data communication between the control units 1, 2, the exchange 4 sets up a transmission path between them and the changeover switch 1c is thrown to the position of the crystal oscillator 1a, the clock pulse frequency of the transmitter side and the receiver side is the same and then pulse distortion caused by difference between clock pulses is reduced.</p> |
