FAULT LOCATION OPERATING SYSTEM WITH LOOPBACK

摘要

FAULT LOCATION OPERATING SYSTEM WITH LOOPBACK A fault-location operating system for use with transmission networks using repeaters with loopback capabilities. A plurality of bidirectional transmission links Li, for i = 1 through N, are used for transmission of data between the terminals. A test control unit is connected at the first terminal to the first end of the first transmission link L1, and controls transmission of control signals across the first transmission link L1. A plurality of repeaters Ri, for i = 1 through N-1, are used for interconnecting the plurality of bidirectional links. Each repeater Ri is connector to the first end of one transmission link Li and to the second end of another transmission link Li+1. Each repeater includes a first circuit for repeating data transmitted from the one transmission link L1 for transmission on the other transmission link Li+1, and a second circuit for repeating data transmitted from the other transmission link Li+1 for transmission on the one transmission link Li. In addition, a loopback circuit is included in each repeater that is responsive to the control signals on the one transmission link Li for looping back data transmitted from the one transmission link Li for transmission back on the one transmission link Li. In this system, each repeater has a loopback capability responsive to control signals sent through the transmission links. The loopback capability can be provided in other elements in the network so that a single test control unit can be used to located faults anywhere within the network.