| 摘要 |
PROBLEM TO BE SOLVED: To reduce load at a high-order device and to continue data communication while eliminating the disconnection of information processors when any abnormality is generated on a LAN transmission line concerning an information processing system for performing the communication of data between the respective information processors connected to the LAN transmission line. SOLUTION: At the information processor connected to the transmission line, a central processing unit(CPU), timer and transmission line control means are provided at least. When any abnormality on the transmission line is detected by the transmission line control means, the transmission line control means monitors time for fixed time while using the timer and during the monitor with the timer, the transmission line control means does not report the abnormality on the transmission line to the high-order device. Besides, even when any abnormality is generated on the transmission line, at the transmission line control means, the CPU reports a transmission frame, in which abnormality occurs, to the high-order device not as abnormal end but as normal end and when that frame is watched from the high-order side, it seems to be lost. Corresponding to communication contents from the information processor on the reception side, the high-order device performs prescribed retry processing. |
