JPH04278748A - Network system - Google Patents

Abstract

PURPOSE:To facilitate the specification of a line fault occurring post in a bus- type network system and to simplify line mending at the time of fault. CONSTITUTION:The line 1 and line 2 are formed by respectively sectioning into section lines 101, 102 and 103 and the section lines 104, 105 and 106 in the bus-type network system including the line 1, the line 2 and work stations 1-3. A fault detecting devices 4 and 5 and a line switching devices 6 and 7 are provided in accordance with the section lines of the line 1 and 2. When fault occurs at the (A) point of the section line 101 of the line 1, fault occurrence is detected by the fault detecting device 4, the section line 101 of the line 1 is switched to the section line 104 of the line 2 by the line switching device 6 by receiving fault information outputted from the fault detecting device 4 and communication normally continues.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network system, and more particularly to a network system applied in a bus-type local area network.

0002

2. Description of the Related Art In a conventional network system of this kind, as shown in an example partial block diagram in FIG.
8 and a line (2) 119 are provided running in parallel, and work stations 19, 20, and 21 are provided to both lines, respectively, and are connected to each other via a transceiver 22.

In FIG. 3, during normal line operation, workstations 19, 20, and 21 operate using either line (1) 118 or line (2) 119. ing. Now, suppose workstations 19, 20 and 21 are on track (1) 11
It is assumed that the system is being operated using 8. In this case, if a failure occurs in line (1) 118 (failure occurrence point C), communication that was being performed via workstations 19, 20, and 21 becomes impossible. Therefore, as a countermeasure, the workstations 19, 20 and 21, which were connected to the line (1) 118 via the transceiver 22, are switched to the line (2) 119, so that the communication between the workstations 19, 20 and 21 is is being maintained.

0004

[Problems to be Solved by the Invention] In the conventional network system described above, when the length of the line used is long, it is necessary to This has the disadvantage that the length of the fault becomes long, making it difficult to identify the point where the fault occurs when a fault occurs.

[0005] Furthermore, if the fault is a fatal fault such as a disconnection or short circuit, the entire line where the fault occurs will have to be replaced, no matter where the fault occurs at any point on the track. There are drawbacks.

[0006]

[Means for Solving the Problems] A network system of a first invention includes a pair of transmission lines running parallel to each other,
In a bus-type network system of one system, a first transmission line formed by being divided into a plurality of section lines with respect to the traveling direction of the network system, and a first transmission line running parallel to the first transmission line, The second section is formed by being divided into a plurality of section tracks in the direction of travel.
fault detection means for commonly detecting the occurrence of a fault in the transmission line and the first and second transmission lines for each corresponding section line of the first and second transmission lines; Line switching means receives the fault detection information output from the detection means and performs a switching control function so as to select a corresponding section line of the transmission line running in parallel in place of the section line where the fault has occurred. It consists of

[0007] Further, the network system of the second invention is a bus-type network system including a network system and a plurality of sub-network systems running in parallel with each other, in which the progress of the network system is controlled within the network system. First and second transmission lines running parallel to each other in the direction of travel and each divided into a plurality of segmented lines; The first and second sub-transmission lines are parallel to each other and are divided into a plurality of sectioned lines, respectively, and the occurrence of a fault in the first and second sub-transmission lines is determined by the first and second sub-transmission lines. Each corresponding section line of the sub-transmission line is commonly detected, and switching control is performed so that the corresponding section line of another sub-transmission line running in parallel is selected instead of the section line where the fault has occurred. and a failure detection switching means that performs the operation.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a partial configuration diagram showing a portion of a first embodiment of the present invention. As shown in FIG. 1, in this embodiment, the line (1) is divided into divided lines 101 and 102.
and 103, and sectioned track 1 obtained by dividing track (2)
04, 105 and 106, workstations 1, 2 and 3, and fault detection devices 4 and 5;
It is configured to include line switching devices 6 and 7, and a transceiver 8 for connecting each workstation, fault detection device, etc. to each section line.

In FIG. 1, it is assumed that line (1) including section lines 101, 102 and 103 is initially selected via line switching devices 6 and 7 and line operation is performed. Therefore, in this case, using line (1), workstations 1, 2 and 3
The line is operating normally. In such an operating state, assuming that a fault occurs at point A of the section line 101 in FIG. 1, the section line 10
Since no failure occurred in 2 and 103,
Workstations 2 and 3 can communicate, but workstation 1 cannot communicate. In this case, the fault detection device 4 detects the connected section line 10 via the corresponding transceiver 8.
Sectional line 101 among 1, 102, 104 and 105
It is detected that a fault has occurred, and fault detection information is output and sent to the line switching device 6. Next, in the line switching device 6, upon receiving the fault detection information,
A fault occurs in the selected section line 101, and it is recognized that there is no fault in the section line 104, and the operating line is switched from the section line 101 to the section line 104 where no fault has occurred. With this switching operation,
As for the operational lines, calls are made through the routes of section lines 104, 102, and 103, and calls between workstation 1 and workstations 2 and 3 are maintained normally.

Next, a second embodiment of the present invention will be explained. This embodiment is an example in which a network is divided into a plurality of subnetworks and operated.

FIG. 2 is a partial configuration diagram showing a part of this embodiment. As shown in FIG. 2, in this embodiment, the line (1
) are divided into sections 107, 108 and 109.
and sectioned tracks 110 and 111 obtained by dividing the track (2).
and 112, failure detection switching devices 15 and 16,
a first network comprising an associated transceiver 18; and a first network provided corresponding to said first network.
sub-network 113, segmented lines 114 and 115 obtained by dividing the line (1), segmented lines 116 and 117 obtained by dividing the line (2), a fault detection switching device 17, and an associated transceiver 18. A second sub-network, a gateway 12 that connects the first network and the first sub-network, gateways 13 and 14 that connect the first network and the second sub-network, and each of these networks. The computer includes corresponding workstations 9, 10, and 11.

[0013] In this embodiment, the network is divided into a plurality of sub-networks, and the communication within each sub-network is not connected to other networks, so that the amount of communication within each network can be reduced. is possible. In the case shown in FIG. 2, the connection between the section lines 107 and 110 of the first network and the section line 113 of the first sub-network is
The connection between the section lines 108 and 111 of the first network and the section lines 114 and 116 of the second sub-network is made via the gateway 1
3, and the connection between the section lines 109 and 112 of the first network and the section lines 115 and 117 of the second subnetwork is made via the gateway 14.

[0014] Now, in the second sub-network, the section line 114 is selected to connect the first network and the second sub-network.
It is assumed that a line operation including sub-networks was being carried out. In such an operating state, assuming that a failure occurs at point B of the section line 114 of the second sub-network, the communication operated between the second sub-network including the section line 114 and the first network is temporarily suspended. At the time of such a failure, the line failure at point B is detected by the failure detection switching device 17 via the transceiver 18, and in this failure detection switching device 17, the line failure at point B is detected by the failure detection switching device 17.
Switching control is performed to select the section line 116 instead of the section line 4, and the section lines 108 and 111 in the first network and the section line 116 in the second sub-network are connected via the gateway 13 as operational lines. The line status is restored to the same state as before the failure, and communication including the first network and the second subnetwork continues normally.

[0015]

[Effects of the Invention] As explained above, the present invention is constructed in such a way that parallel tracks are divided into a plurality of segmented tracks, and when a failure occurs in a part of the track during communication operation, By automatically switching the divided line where the fault has occurred to the divided line of a second line running parallel to the said track, it is possible to prevent line operation from being interrupted, and also because the line is divided into sections. This method has the advantage that it is extremely easy to identify the fault point, and when repairing the line, complete restoration can be achieved by replacing only the section line where the fault has occurred.

[Brief explanation of the drawing]

FIG. 1 is a partial configuration diagram showing a part of a first embodiment of the present invention.

FIG. 2 is a partial configuration diagram showing a part of a second embodiment of the present invention.

FIG. 3 is a partial configuration diagram showing a part of a conventional example.

[Explanation of symbols]

1-3, 9-11, 19-21 Workstation 4, 5 Fault detection device 6, 7 Line switching device 8, 18, 22 Transceiver 12-14 Gateway 15-17 Fault detection switching device

Claims (2)

[Claims] Claim 1: In a bus-type network system including a pair of transmission lines running parallel to each other, a first transmission line is divided into a plurality of divided lines in the traveling direction of the network system. railway track and the first
a second transmission line that runs parallel to the transmission line and is divided into a plurality of section lines with respect to the traveling direction of the network system; Fault detection means commonly detects each of the corresponding section lines of the first and second transmission lines, and upon receiving fault detection information output from the fault detection means, Instead, a network system comprising a line switching means that performs a switching control function to select a corresponding section line of transmission lines running in parallel. 2. In a bus-type network system including a network system running parallel to each other and a plurality of sub-network systems, within the network system, the network systems run parallel to each other in the traveling direction of the network system. , first and second transmission lines each formed by being divided into a plurality of sectioned lines; The first section is divided into tracks.
and detecting the occurrence of a fault in a second sub-transmission line and the first and second sub-transmission lines for each corresponding section line of the first and second sub-transmission lines, and , fault detection switching means that performs a switching control function so as to select a corresponding section line of another sub-transmission line running in parallel in place of the section line where the fault has occurred;
A network system comprising: