| 摘要 |
PURPOSE:To prevent the generation of an ineffective data and to release the limitation of the number of times of relaying to eliminate the generation of error data, by transmitting under-transmission signals of the voltage shorter than a data signal period in a fixed time T and another voltage in the time T. CONSTITUTION:When the data is transmitted to a data line 14, the voltage E1 is sent concurrently to an under-transmission signal line 15. In this case, the voltage E1 is switched to the voltage E2 at a time point earlier than a period for data transmission in a fixed time T. Thus the voltage E2 is transmitted for the time T. After transmission of the E2, a data transmitter/receiver is connected to a bus line with high impedance. The data signals (a) and the under-transmission signal (b) on the bus line are shown by diagrams (a) and (b) respectively. The signals (a) and (b) are reproduced and delivered from drivers 13 and 13' via a discriminating circuit 43, a delay circuit 41 and an OR circuit 42. Therefore the transmission period of the signal (b) is not extended for each relay of the signal (a). This prevents the reduction of data intervals and eliminates the limitation of the number of times of repaying. |
