| 摘要 |
PURPOSE:To monitor the system at all times without stopping the system by detecting the unexecution of data transmission, sending a test data from a 1st modulator-demodulator, fetching the returned data by a 2nd modulator- demodulator so as to grasp the propriety of equalization. CONSTITUTION:A transmission data SD sent from a communication controller via a signal line 6 is modulated by a modulation section 9 and sent to a line 5a. A transmission request signal RS is sent to the modulation section 9 and a detection means 30 via a signal line 7. In receiving the signal RS, a pseudo data transmission control section 12 gives a command to a pseudo data generating section 13 and sends the pseudo data to the modulation section 9 after a prescribed time after the signal RS is inactive and the signal modulated by the pseudo data is sent to the line 5a. When the signal RS is active, the transmission of the pseudo data is stopped. The datareturned from the line 5b is given to a comparison section 14 via a demodulation section 10, it is compared with the sent pseudo data to detect the presence of coincidence. Thus, the test is conducted easily during the operation of the system. |
