A reconfigurable serial loop multiplex communication system for communication of digital and analog status and control information between field terminal locations or to a central control location via a twisted pair line. Input modules in a first terminal station communicate signals received at their input to output modules having the same byte address in other terminal stations. At the central control locaton, signals from an input module may be readdressed for communication to output modules h...

A digital communication system is disclosed for communicating among two central consoles and a plurality of local controllers, such as may be used in a radiation and monitoring system and the like. Communication occurs between each of the consoles and all of the local controllers via dual paths, each of which comprises a bidirectional duplex two wire communication link. Each path is independent of the other and each extends from one of the consoles to all of the local controllers from opposite d...

A double loop transmission system is provided in which not only bypass routes but also terminals are connected with a pair of transmission control units of each loop. In this manner, the transfer of a message is controlled by both the information concerning whether the smaller loop formed by a pair of the adjacent transmission control units is abnormal or not and the bypass code data contained in the message. The transmission can thus be continued no matter which loop has its transmission contro...

The stations (S1to SN) are interconnected in series by a ring (A), and the system of the invention includes a spare ring (AS) interconnecting the stations in series, together with two self-healing circuits (CAM, CAV) in each station coupler (CS) between the two connectors (8, 9) of the coupler and its insertion relay (RI). The couplers are interconnected by cords (10; 11) each containing the ring (A), the spare ring (AS), and two detection links (12, 13). Each self-healing circuit includes a rel...

A ring network data transmission system includes a plurality of transmission apparatuses, at least one terminal connected to each of the transmission apparatuses and double ring transmission paths interconnecting the transmission apparatuses in a ring-like system configuration so that terminals can communicate with one another through the associated transmission apparatuses. When a transmission fault occurs in the network, the transmission apparatus which can serve as the master station issues t...

An SDH (synchronous digital hierarchy) 2-fiber ring network optical multiplexing device, which, in order to increase the amount of usable bandwidth when the network is operating normally by selectively limiting the number of protection channels when a communications fault is detected, has opto-electrical converters and electro-optical converters for the purpose of sending and receiving signals on each optical transmission path in two directions, a channel operating section which perform operatio...

A fault permission network arrangement having a plurality of packet transfer units connected in a ring form. Each of the plurality of packet transfer units comprises first and second nodes, each of the first and second nodes having two inputs and two outputs, for inputting the same data from previous-stage two nodes, abandoning one of the input data and transferring the other data to subsequent-stage two nodes, and an interface unit having two inputs and two outputs connected to the first and se...

1:N duplex communication equipment which has a host device and slave devices interconnected in a ring form is disclosed. In the equipment, the path distributing part 3 of the host device transmits an identical path to the two-way transmission line of the ring, and a path selecting part 4 selects a normal one of paths from the two-way transmission lines. The path distributing part 6 of each slave device distributes a path from one transmission line to the other transmission line and the path sele...

The disclosure relates to apparatus and methods that provide a system interconnect for transporting cells between nodes on a dual counter-rotating ring network, including a link selection register for selecting the shortest path to a destination node, use of a fault tolerant frequency reference to synchronize node clocks, interconnect initialization, multi-ring topologies along with an addressing schema and ring-to-ring couplers. The disclosure also discusses flow control of cells leaving nodes,...

A fiber optic synchronous digital hierarchy telecommunication network provided with a protection system shared on the network is described, which comprises spans of pairs of optical fibers (N.times.2F) having network elements (N.times.2F-SDHNE) interposed therebetween, wherein the spares of pairs of optical fibers have a variable number N (N=1, 2, 3, . . . ) of pairs, and the network elements (N.times.2F-SDHNE) feature variable interconnection capability between said spans, so that several spans...