| 摘要 |
A communication system has a first station (SO) and a plurality of further stations (S1-S4), two communication channels (A, B), for transmission in opposite directions, serially connecting the stations. The first station includes routing means operable in a double looped mode to route signals received on each channel onto the respective other channel and the further stations each including routing means operable in a through mode to forward, in the same channel, signals received on each channel, thereby forming a single folded transmision path. Preferably the further stations each are responsive to the cessation of signalling energy (e.g. a break in the transmission path) on a channel to assume a looped mode in which signals received in the other channel are rerouted onto that channel, with the first station responding by assuming a through mode in which signals received on each channel are forwarded in the same channel, again forming a single folded transmission path following rerouting at two of the further stations. |
