UEBERTRAGUNGSEINRICHTUNG UND STERNSCHALTUNG ZUR VERWENDUNG IN EINER SOLCHEN UEBERTRAGUNGSEINRICHTUNG UND EINRICHTUNG MIT EINER SOLCHEN SCHALTUNG.

摘要

In a communication device with a star circuit (7) all electrical bus connections (4, 5, 6) are terminated by their characteristic impedance (8, 9, 10) at the side of the stations (1, 2, 3) as well as at the side of a star circuit. In order to enable arbitrary connection/disconnection of stations without modification of the terminating impedances while at the same time the termination remains optimum, each bus connection is provided with a separating element (11, 12, 13). This element receives an active bus connection state and communicates this state to all other connections so that the local bus connections are also activated. However, when a bus connection is activated in this manner, an inhibit signal is also applied to the relevant separating element so that the latter cannot signal a further activation. Furthermore, for each connection there is provided a logic circuit (17) in order to prevent the signalling of the own activation back to the own bus connection, while the inhibit signal for the own bus connection need not be active either.