JPS59190755A - Channel duplexing system - Google Patents

Abstract

PURPOSE:To obtain a channel duplexing system which requires a loop-back connection even when a transmission line is abnormal by connecting plural nodes in a loop by two-way transmission lines, and transmitting and receiving the same data through two paths. CONSTITUTION:The nodes 21-25 are connected in a loop through the two-way transmission lines 26-30. A node 31 receives data from transmission lines 33 and 34 by data receivers 36 and 37 and sends them out to transmission lines 35 and 32 through switches 382 and 381. Further, the switches 382 and 381 are connected to dotted-line sides in transmission to transmit transmit data of a data transmitter 39 to transmission lines 35 and 32 simultaneously. Consequently, even if one two-way transmission line becomes abnormal, only one path among the nodes becomes abnormal and the other path is still normal, so communication among the nodes is carried on without employing any loop-back connection.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to duplication of a communication path in communication between nodes connected by a loop-type transmission path.

(Conventional technology) FIG. 1 shows a conventional duplex communication channel system.

1 to 5 are nodes, 6 to 10 are bidirectional data transmission lines, solid lines are active data transmission lines, dotted lines are backup data transmission lines, and arrows indicate signal directions.

Normally, communication is performed using only the data transmission path shown by the solid line among the data transmission paths 6 to 10, but for example, when an abnormality occurs in the data transmission path 8, the node 3 to which the data transmission path 8 is connected In steps 4 and 4, loopback connections 11 and 12 were created and communication was performed by changing the route.

Therefore, there is the disadvantage that it is necessary to determine the node to create a loopback connection in the event of an abnormality, and the disadvantage that abnormality confirmation of the backup data transmission path is not performed because the backup data transmission path is not used in normal times. was there.

(Object of the Invention) In order to eliminate these drawbacks, an object of the present invention is to provide a simple communication path duplex system that does not perform loopback connection when a data transmission path is abnormal.

(Structure of the Invention) The present invention provides a duplex communication system having a plurality of nodes and a data transmission path connecting them, in which each node is connected in a roof-like manner by a bidirectional data transmission path, and one seven-point A function that sends the same data to two bidirectional data transmission lines connected to one node only when the node is in the transmitting state, and a function that transmits the same data to two bidirectional data transmission paths connected to the node except when the node is in the transmitting state. This communication duplex system is characterized in that each node is provided with a function of receiving data from a transmission path and relaying the received data to an adjacent node on the opposite side from the direction in which it was received.

Hereinafter, the present invention will be described in detail with reference to embodiments and drawings.

(Embodiment) FIG. 2 is a diagram of a node and a data transmission line connection form according to an embodiment of the present invention, and FIG. 3 is a functional block diagram of the node in FIG. 2. In Figure 2, 21, 22, 2
3, 2, 4 and 25 are nodes, 26°27.28.
Reference numerals 29 and 30 are bidirectional data transmission paths, which connect the nodes 21, 22, 23, 24, and 25 in a loop. In addition, in FIG. 3, 3I is a node, 32 and 33 are data transmission lines connected to adjacent node n, and 3
4 and 35 are data transmission lines connected to adjacent node m. 36. 37 is a data receiving device, 381°38
A switch 2 performs a relay operation between nodes. 39 is a data transmitting device.

These operations will be explained. Each node always receives data from the data transmission path 33 using the data receiving device 36,
The data receiving device 37 also receives data from the data transmission path 34 . At this time, switches 38Z, 382
is located at the position shown by the solid line.

Switch, only during transmit state? 8 Z, 3 B
2 is connected to the dotted line side, and transmit data from the data transmitting device 39 is simultaneously transmitted to the data transmission path 32 and the data transmission path 35.

When not in the transmitting state, switches 381 and 382 are connected to the solid line side, and data from the data transmission line 33 is relayed to the data transmission line 35, and data from the data transmission line 34 is relayed to the data transmission line 32. .

Furthermore, by setting a link protocol that prevents multiple nodes from being in a transmitting state at the same time, data transmitted by one node can be received by all nodes at the same time. At this time, each node receives data through both clockwise and counterclockwise paths.

By doing this, even if an abnormality occurs in one bidirectional data transmission path, only one path among the routes between nodes will become abnormal, and the other paths will remain healthy, allowing loopback connections. This has the advantage that communication between nodes can be continued without using .

In addition, since the transmitted data passes through all data transmission paths and can be received at the sending node during normal times, there is no need to constantly check for abnormalities in the data transmission path, which has the advantage of being able to detect abnormalities in the data transmission path at an early stage. There is also.

(Effects of the Invention) Since the present invention transmits and receives the same data over two routes, it has the advantage that communication can be continued without changing the route even in the event of an abnormality in the data transmission path. Since a decision algorithm and a route change circuit are not required, it can be easily used in information transmission systems that require duplication of communication channels.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional communication path redundancy system, FIG. 2 is a block diagram of an embodiment of the present invention, and FIG. 3 is a functional block diagram of a node according to an embodiment of the present invention. 1.2. ．． 3,4,5,21,22,23,24゜25
, ,? 1... Node, 6, 7,
8, 9, Z O, 26° 27, 2
8', 29, ? 0...Bidirectional transmission line, 1
1゜12...Loop bank connection 1.12.33.34.
35...Data transmission path, 36.37...Data receiving device 1, ? 81, 382... switch, 39...
・Data transmission device 0 Figure 1 Blind t+12 II Figure 2 1 Figure 3 1 Commissioner of the Japan Patent Office 1, Indication of the case 1982 Patent Application No. 063780 2, Name of the invention Communication channel duplex system

Claims (1)

[Claims] In a communication line redundant system that has multiple nodes and data transmission paths connecting them, each node is connected in a loop by a bidirectional data transmission path, and one node is connected to that one node only when it is in a transmitting state. A function to transmit the same data to two bidirectional data transmission paths connected to the node, and a function to receive data from two bidirectional data transmission paths connected to the node when not in the sending state. A communication path duplex system characterized in that each node is provided with a function of relaying data to an adjacent node on the opposite side from the direction in which it is received.