| 摘要 |
PURPOSE:To switch the switching of a redundancy system and the failure detection of a waiting side without providing a centralized control station, by performing the redundancy control in a station having minimum time value of a timer among communication stations of a system. CONSTITUTION:A system of the operating side of each communication station 1i fetches data for itself from a frame in accordance with a flag of the frame in circulation and a control sentence and when the leadership is given, data for other stations is inserted in the frame. Further, the waiting side system circulates the waiting frame. Each station is provided with the timer, the time set of the timer is different from each other, the minimum value of the set time is decided in a value not below the frame interval at the normal communication, and at time-up, a controller C of each station starts the transmission of a prescribed frame. The frame at the start of communication includes the actual operating system indicating information, the corresponding system is operated at the lower stream station with this information, the other systems are waited, allowing to decide the operating and the waiting side at the sytem start. |
