Abstract: In a system comprising a collection of signal processing apparatuses and a switching device, each apparatus is connected, by means of a universal connector which is identical for each apparatus, to an arbitrary connection of the said switching device. The signal path between two or more connected apparatuses is established in that a first apparatus supplies a report command for the switching device in a least one further apparatus, after which the switching device finds out to which connector a further apparatus is connected in that said further apparatus in reaction to the report command has supplies an identification signal as a result of which the switching signal recognises the connector to which said further apparatus is connected. Once it has been found out to which connector the first and the further apparatuses have been connected, the switching signal establishes a signal path herebetween.

Abstract: In a communication device with a star circuit all electrical bus connections are terminated by their characteristic impedance at the side of the stations 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. 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 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 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.