| 摘要 |
The communication network comprises a bus (1, 2) wired after the manner of a ring which can be broken at any point and closed by resistors (5a, 5a', 5b, 5b') and several stations (S) connected by the bus. Each station (S) has two relays (3a, 3b) to separate the connections (A, B) to the neighbouring stations and to each relay (3a, 3b) are allocated two resistors (5a, 5a', 5b, 5b') which form the terminating resistors with the relays separated. During operation the stations (S) transmit presence telegrams, the absence of which indicate the breakdown of the station concerned and triggers the switchover of the relays (3a, 3b) of all the stations to the separated setting. The stations then test the connections by alternately switching the relays over and transmitting telegrams. The selection of the relays to be switched over and the selection of the duration of the connection test is arbitrary. A conection recognised as faulty is cut out of the network by switching over the two neighbouring relays into the separated position. |
