Abstract: An ATM path changing system and method for use in an ATM communication apparatus and ATM communication network are provided which can set an alternating route in the event of a failure occurring in a transmission line or VP. A header converter in a line controller includes a plurality of output path routing tables, a selector, a comparator, a register for failure RTG and a register for failure VPI and when the contents of the register for failure RTG or VPI coincides with a RTG or VPI of the output path routing tables, an output is selected in accordance with the contents of a selected emergency-route RTG or VPI register.

Abstract: A looped bus system includes several nodes connected by unidirectional buses having opposite directions of signal transmission. The head of bus function for each bus is located at a node different from the head of bus function for the other bus. The head of bus function for each bus is located at the same node as the termination of bus function for the other bus. As a result, the buses can be reconfigured and nodes can be added freely by the use of a bus portion that is unused in the looped bus under normal condition.

Abstract: An ATM path changing system and method for use in an ATM communication apparatus and ATM communication network are provided which can set an alternating route in the event of a failure occurring in a transmission line or VP. A header converter in a line controller includes a plurality of output path routing tables, a selector, a comparator, a register for failure RTG and a register for failure VPI and when the contents of the register for failure RTG or VPI coincides with a RTG or VPI of the output path routing tables, an output is selected in accordance with the contents of a selected emergency-route RTG or VPI register.

Abstract: A looped bus system includes several nodes connected by unidirectional buses having opposite directions of signal transmission. The head of bus function for each bus is located at a node different from the head of bus function for the other bus. The head of bus function for each bus is located at the same node as the termination of bus function for the other bus; As a result, the buses can be reconfigured and nodes can be added freely by the use of a bus portion that is unused in the looped bus under normal condition.

Abstract: A switching system which includes subscriber's circuit device connected to terminals and a subscriber's circuit controlling apparatus between a host apparatus and subscriber's circuit devices for controlling the subscriber's circuit devices in accordance with a control order corresponding to control information from the host apparatus. Each of the subscriber's circuit controlling apparatuses includes an order processing unit which analyzes control information which is transmitted from the host apparatus for comparing the received control information with last received control information and transmits a control order to the subscriber's circuit devices. The order processing unit transmits control orders a number of times to the subscriber's circuit devices and accepts a fault report, from the subscriber's circuit devices to retransmit a control order. The subscriber's circuit devices receive the control order a number of times for collating the control orders and outputs a fault report when in disagreement.