| 摘要 |
PROBLEM TO BE SOLVED: To provide a ring network interface which solves the problem wherein, because of no means for recognizing the transmission conditions on a ring network 03 in the conventional annular network interface 1, a selector 3 is switched from a bypass side (at an information terminal A) to a network communication participation side (at an input terminal B), upon recognizing that a related station 02j goes to communication-enabled state, irrespective of the transmission condition at that time, so that, when the station 02j goes to a communication-enabled state during passing of a transmission frame 20, the transmission frame 20 is broken at the time of switching by the selector 3, to cause a communication failure. SOLUTION: An interface 1j of a station 02j for an annular communication network composed of a plurality of stations, connected annularly through a plurality of serial communication cables 04 for transferring data via transmission frames 20, flowing in a specified direction in the ring switches the route of the transmission frames passing in the station, according to whether the station participates a communication on the right type communication network to a bypass communication line 9 for directly transmitting the transmission frames received from the previous station 02i to the next station 02k, or to a transmission frame input/output circuit 2 for transmitting data addressed to this station fetched from the transmission frames received from the previous station to transmit remaining transmission frames to the next station, and also to transmit the transmission frames received from the previous station, together with added data addressed from this station to other stations, to the next station, thereby avoiding breaking of the transmission frames at switching by the selector 3 by to a signal 8. COPYRIGHT: (C)2005,JPO&NCIPI
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