JP2001086038A - Information transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information transmission device which can continue information transmission, when a line is abnormal and which needs the small number of lines connection nodes positioned on both ends. SOLUTION: A line 91 transmits a line state signal U1 (E1) in a certain direction a1. A line 92 transmits a line state signal U2 (E2) in a certain direction a2. The number of preliminary lines 81 is smaller than the number of lines 91 and 92. Two switches 21 and 22 are connected by the preliminary line 81 and are connected by nodes 11 and 16 positioned on both ends. At least one switch 21 detects the abnormality of the line by decoding the line state signal U1 (E1) supplied from the node 11. When one switch 21 detects the abnormality of the line, it supplies an information signal S1 supplies from the node 11 to the other switch 22 via the preliminary line 81. The other switch 22 supplies the information signal S1, supplied from one switch 21 to the node 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an information transmission apparatus.

[0002]

2. Description of the Related Art Various types of information transmission devices for transmitting information between a plurality of nodes are known.
Among these, in one information transmission device, a line sequentially connects a plurality of nodes to make a circuit. Then, information is transmitted clockwise and counterclockwise on this line. In such an information transmission device, information transmission can be continued even when a line is disconnected at a certain point.

In such an information transmission apparatus, a plurality of lines are provided for transmitting a large amount of information, and these lines make a round by connecting a plurality of nodes sequentially. Then, information is transmitted clockwise and counterclockwise on each line. In this case, of the plurality of nodes, nodes located at both ends are also connected to each other by respective lines. Therefore, the line installation cost and the maintenance cost increase.

[0004] By the way, a train central control device (hereinafter referred to as CTC)
In this case, a central device, a plurality of general station devices, and a terminal station device are provided at a distance from each other along a railway line. In an example in which the above-described information transmission device is applied to such a CTC device, each line sequentially connects a central device, a plurality of general station devices, and a terminal station device. Furthermore,
A plurality of bypass lines are provided for each line,
These bypass lines directly connect the terminal station equipment and the central equipment, respectively. In this case, the same number of bypass lines as the number of lines must be laid between the terminal station device and the central device, and the cost of laying and maintaining the bypass lines is large.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an information transmission apparatus which can continue information transmission when a line abnormality occurs.

Another object of the present invention is to provide an information transmission apparatus which requires a smaller number of lines for connecting nodes located at both ends among a plurality of nodes.

[0007] Still another object of the present invention is to provide an information transmission apparatus capable of reducing a line laying cost and a maintenance cost.

[0008]

To solve the above-mentioned problems, an information transmission apparatus according to the present invention includes a plurality of lines, a plurality of nodes, at least one protection line, and two switches. .

[0009] The plurality of nodes are sequentially connected by each of the plurality of lines, and each node supplies at least one of an information signal and a line state signal to each of the plurality of lines. The line status signal is transmitted in a fixed direction on each of the plurality of lines.

[0010] The at least one protection line is provided in a number smaller than the number of the plurality of lines. The two switches are respectively connected to each other by the protection line, and are connected to nodes located at both ends of the plurality of nodes.

At least one of the two switches is supplied with the line state signal from a node connected thereto, detects a line abnormality by decoding the line state signal, and detects a line abnormality. Is detected, the information signal is supplied from a node connected thereto, and the information signal is supplied to the other switch via the protection line. The other switch supplies the information signal to a node connected thereto when the information signal is supplied from the one switch.

In the above-described information transmission apparatus according to the present invention, the plurality of nodes are sequentially connected to each of the plurality of lines, and each node transmits an information signal or a line state signal to each of the plurality of lines. Supply at least one. Accordingly, each line is supplied with an information signal and a line state signal, and each line transmits the information signal and the line state signal.

The line status signal is transmitted in a certain direction on each of the plurality of lines. Therefore, the line status signal transmitted on each line is supplied to any one of the nodes located at both ends.

Each of the two switches is connected to nodes located at both ends of the plurality of nodes. Therefore,
The line status signal transmitted on each line is supplied to a switch connected to that node via one of the nodes located at both ends.

At least one of the two switches is supplied with a line state signal from a node connected thereto, and detects a line abnormality by decoding the line state signal. Therefore, when a line abnormality such as noise intrusion or disconnection occurs in any one of a plurality of lines, one of the two switches detects the line abnormality.

Each of the two switches is connected to each other by a protection line. When one of the two switching devices detects a line abnormality, the information signal is supplied from the node connected to itself and the information signal is supplied to the other switching device via the protection line. I do. The other switch supplies the information signal to the node connected thereto when the information signal is supplied from the one switch. As described above, when a line abnormality occurs in any one of the plurality of lines, the information signal is transmitted from one of the nodes located at both ends to the other node via the protection line. You. Therefore, a detour path of the information signal is formed, and the information transmission can be continued.

The number of the protection lines is less than the number of the plurality of lines. According to the information transmission apparatus of the present invention, even when the number of protection lines is smaller than the number of a plurality of lines, the above two switches can continue information transmission when a line abnormality occurs.

As described above, in the conventional information transmission apparatus, a plurality of lines make a round by sequentially connecting a plurality of nodes. In this case, among the plurality of nodes, the nodes located at both ends are connected to each other by the respective lines, so that the line installation cost and the maintenance cost increase.

On the other hand, in the information transmission apparatus of the present invention,
The number of protection lines connecting nodes located at both ends is smaller than the number of lines connecting a plurality of nodes sequentially. Therefore, it is possible to reduce the line installation cost and the maintenance cost.

The other features of the present invention and the operation and effects thereby will be described in more detail with reference to the accompanying drawings. The accompanying drawings show by way of example only.

[0021]

1 to 3 schematically show the configuration of an information transmission apparatus according to the present invention. As shown, the information transmission apparatus according to the present invention includes a plurality of lines 91 and 9.
2, a plurality of nodes 11 to 16, at least one protection line 81, and two switches 21 and 22. The illustrated information transmission device is an example applied to a CTC device. FIG. 1 is a diagram illustrating a case where all of a plurality of lines are normal.

In the embodiment, two lines 91 and 92 are provided, but the number of lines is arbitrary. Line 9
Reference numerals 1 and 92 are constituted by transmission cables and the like.

The plurality of nodes 11 to 16 are sequentially connected by respective lines 91 and 92. In the embodiment, six nodes 11 to 16 are provided, but the number of nodes is arbitrary plural. Further, a plurality of nodes 11 to
16 are connected to each other in series by respective lines 91 and 92. The plurality of nodes 11 to 16 are
1 are arranged so as to gradually move away from each other.

In the embodiment, a plurality of nodes 11 to 16
Are arranged at a distance from each other along a railway line. The node 11 is a central device, the nodes 12 to 15 are general station devices, and the node 16 is a terminal station device. The node 11 that is a central device is connected to nodes 12 to 15 that are general station devices and a node 16 that is a terminal station device.
Provides control information. Nodes 12-1 consisting of general station equipment
5 and the node 16 which is a terminal station device supply its own display information to the node 11 which is a central device.

In the present invention, each of the nodes 11 to
16 supplies the line 91 with at least one of the information signal S1 and the line state signal U1 (E1). Furthermore,
Each of the nodes 11 to 16 supplies at least one of the information signal S2 and the line state signal U2 (E2) to the line 92. Line state signals U1 (E1), U2 (E
2) is a signal independent of each other for the lines 91 and 92. The line state signal U1 (E1) is a line state signal indicating the line state of the line 91, and the line state signal U2 (E2) is a line state signal indicating the line state of the line 92. The line state signals U1 and U2 are line state signals each indicating "no abnormality". The line state signals E1 and E2 are line state signals indicating "abnormal".

In the present invention, the line state signal U1 (E
1) and U2 (E2) are transmitted in fixed directions a1 and a2 on a plurality of lines 91 and 92, respectively. Specifically, the line state signal U1 (E1) is transmitted in a fixed direction a1 on the line 91, and the line state signal U2 (E2)
Is transmitted on line 92 in a fixed direction a2.

In the embodiment, the plurality of lines 91 and 92 include two lines 91 and 92 through which line state signals U1 (E1) and U2 (E2) are transmitted in directions a1 and a2 opposite to each other. Of the directions a1 and a2, the direction a1 is a plurality of lines 9
1 and 92 on the direction from the node 16 to the node 11. The direction a2 is a direction from the node 11 to the node 16 on the plurality of lines 91 and 92. The two directions a1 and a2 described above are directions opposite to each other.

In the embodiment, the node 16 generates a line state signal U1 indicating "no abnormality" and transmits the line state signal U1 indicating "no abnormality" to the node 15 through the line 91. Since the operations of the nodes 15 to 12 are substantially the same, the operation of the node 13 will be described as a representative. Node 13
Transmits a "no abnormality" line state signal U1 to the node 12 through the line 91 when receiving the "abnormal" line state signal U1 from the node 14 through the line 91.
The node 11 receives the line state signal U1 indicating “no abnormality” from the node 12 via the line 91.

Further, in the embodiment, the node 11
A line state signal U2 of “abnormal” is generated, and a line state signal U2 of “abnormal” is transmitted to the node 12 through the line 92. Since the operations of the nodes 12 to 15 are substantially the same, the operation of the node 14 will be described as a representative. The node 14 receives "no abnormality" from the node 13 through the line 92.
When the line state signal U2 is received, the line state signal U2 indicating "no abnormality" is transmitted to the node 15 through the line 92. The node 16 receives the line state signal U2 indicating “no abnormality” from the node 15 via the line 92.

In the present invention, at least one spare line 81 is provided in a number smaller than the number of the plurality of lines 91 and 92. In the embodiment, as described above, the lines 91, 92
Are two, only one of the protection lines 81 is provided. Unlike the embodiment,
When the number of lines is, for example, four, the number of protection lines is one of one to three, which is smaller than the four. The protection line 81 is configured by a transmission cable or the like, like the lines 91 and 92 described above.

The two switches 21 and 22 are connected to each other by a protection line 81. Further, the two switches 21 and 22 are respectively connected to a plurality of nodes 11 to 1
6 are connected to nodes 11 and 16 located at both ends. Specifically, of the two switching devices 21 and 22,
One switch 21 is connected to the node 11, and the other switch 22 is connected to the node 16. In the embodiment, one switch 21 is connected to the node 11 by each of the lines 91 and 92 described above, and the other switch 22 is also connected to the node 16 by each of the lines 91 and 92 described above. I have.

At least one of the two switches 21 and 22 receives the line state signal U1 (E1) from the node 11 connected thereto and decodes the line state signal U1 (E1). This detects a line abnormality. In the embodiment, the other switch 22 is also supplied with the line state signal U2 (E2) from the node 16 connected thereto, and detects a line abnormality by decoding the line state signal U2 (E2).

In the embodiment, the node 11 is the node 1
2 from the line 91 via the line 91 to the line state signal U indicating "no abnormality"
1 when receiving one of the switches 21
Is supplied with a line state signal U1 indicating "no abnormality". The switch 21 detects that “there is no abnormality in the line 91” when the line state signal U1 of “there is no abnormality” is supplied from the node 11.

Further, in the embodiment, when the node 16 receives the "abnormal" line state signal U2 from the node 15 through the line 92, the node 16 transmits the "abnormal" line state signal to the other switch 22 through the line 92. Supply U2.
The other switch 22 detects that "there is no abnormality in the line 92" when the line state signal U2 of "no abnormality" is supplied from the node 16.

In the embodiment, out of the plurality of lines 91 and 92, when the line 91 is not detected as a line abnormality, the line a2 has a direction a2 opposite to the transmission direction a1 of the line state signal U1.
To the information signal S1. Similarly, line 92 is
When the self is not detected as a line abnormality, the line state signal U2
The information signal S2 is transmitted in the direction a1 opposite to the transmission direction a2.

First, the information signal S transmitted on the line 91
1 will be described. Node 11 receives information signal S1
Generate The information signal S1 includes each of the nodes 11 to 1
6 is embedded with control information. Node 11
Transmits the generated information signal S1 to the node 12 through the line 91. Node 12 is connected from node 11 to line 9
When the information signal S1 is received through the node 1, the information signal S1 is transmitted to the node 13 through the line 91. Node 13
The operations of to 15 are the same as the operations of the node 13 described above. Node 16 receives information signal S1 from node 15 via line 91.

Next, the information signal S transmitted on the line 92
2 will be described. The node 16 outputs the information signal S
2 is generated, its own display information is embedded in the generated information signal S2, and this information signal S2 is transmitted to the node 15 through the line 92. Since the operations of the nodes 15 to 12 are substantially the same, the operation of the node 14 will be described as a representative. When receiving the information signal S2 from the node 15 via the line 92, the node 14 embeds its own display information in the information signal S2 received from the node 15, and transmits this information signal S2 to the node 13 via the line 92. Node 11 receives information signal S from node 12 through line 92.
2 is received.

FIG. 2 is a diagram showing a case where an abnormality occurs in one of a plurality of lines in the information transmission apparatus shown in FIG. As shown in FIG. 2, it is assumed that the line 91 is disconnected between the adjacent nodes 13 and 14. The cut location is indicated by reference numeral C1.

Referring to FIG. 2, a case where the line 91 has an abnormality between the adjacent nodes 13 and 14 will be described. As shown in the figure, it is assumed that the node 14 has transmitted a line state signal U1 indicating "no abnormality" to the node 13 through the line 91. The transmitted "abnormal" line state signal U1
Is cut off by cutting C1.

When the node 13 does not receive the line state signal U1 (E1) from the node 14 through the line 91,
A line state signal E1 indicating “abnormal” is generated, and a line state signal E1 indicating “abnormal” is transmitted to the node 12 through the line 91.

When the node 12 receives the "abnormal" line state signal E1 from the node 13, it transmits the "abnormal" line state signal E1 to the node 11 through the line 91.

When the node 11 receives the "abnormal" line state signal E1 from the node 12, the one switch 21 through the line 91 sends the "abnormal" line state signal E1.
Supply 1

When one of the switches 21 receives the line state signal E1 indicating “abnormal” from the node 11, the switch 21 detects that “the line 91 has an abnormality” and sends the “switch 91” to the other switch 22 through the protection line 81. The line state signal E1 indicating "abnormal" is transmitted.

In the present invention, when one of the switches 21 detects a line abnormality, the information signal S 1 is supplied from the node 11 connected to itself, and the information is sent to the other switch 22 via the protection line 81. Supply signal S1. More specifically, when the node 11 receives the "abnormal" line state signal E1 from the node 12, the node 11 transmits the information signal S1 described above.
The signal is supplied to one switch 21 through a line 91. One switch 21 converts the supplied information signal S1 into the protection line 8
1 to the other switch 22.

In the present invention, when the information signal S1 is supplied from the one switch 21, the other switch 22 supplies the information signal S1 to the node 16 connected thereto.
More specifically, when the other switch 22 receives the information signal S1 from the one switch 21, the other switch 22 receives the received information signal S1.
Is supplied to the node 16 through the line 91.

When the information signal S 1 is supplied from the other switch 22, the node 16
5, the information signal S1 is transmitted. Node 15 is node 1
6, when the information signal S1 is received through the line 91,
The information signal S1 is transmitted to the node 14 through the line 91. The operations of the nodes 14 to 12 are the same as the operations of the node 15 described above.

In FIG. 2, of the plurality of lines 91 and 92,
Line 92 is normal. The operation related to the line state signal U2 and the information signal S2 transmitted on the line 92 is shown in FIG.
The operation is the same as that shown in FIG.

FIG. 3 is a diagram showing a case where an abnormality occurs in one of a plurality of lines in the information transmission apparatus shown in FIG. As shown in FIG. 3, it is assumed that the line 92 is disconnected between the adjacent nodes 13 and 14. The cut location is indicated by reference numeral C2.

Referring to FIG. 3, a description will be given of a case where the line 92 has an abnormality between the adjacent nodes 13 and 14. As shown in the figure, it is assumed that the node 13 has transmitted a line state signal U2 indicating "no abnormality" to the node 14 through the line 92. The transmitted "no error" line state signal U2
Is blocked by the disconnection C2.

When the node 14 does not receive the line status signal U2 (E2) from the node 13 through the line 92,
A line state signal E2 of “abnormal” is generated, and a line state signal E2 of “abnormal” is transmitted to the node 15 through the line 92. Further, the node 14 receives the line 9 from the node 13.
When the line state signal U2 (E2) is not received through the line 9, the information signal S2 is generated, its own display information is embedded in the generated information signal S2, and this information signal S2 is
2 to the node 15.

When the node 15 receives the “abnormal” line state signal E 2 from the node 14, it transmits the “abnormal” line state signal E 2 to the node 16 through the line 92. Further, when the node 15 receives the information signal S2 from the node 14, the node 15 embeds its own display information in the received information signal S2, and transmits the information signal S2 to the node 16 through the line 92.

When the node 16 receives the "abnormal" line state signal E2 from the node 15, the other switch 22 transmits the "abnormal" line state signal E through the line 92.
Supply 2.

When the line state signal E 2 indicating “abnormal” is supplied from the node 16, the other switch 22 detects “abnormal in the line 92” and sends the “switch 92” to the one switch 21 through the protection line 81. A line state signal E2 indicating "abnormal" is transmitted.

In the embodiment, when the other switch 22 detects a line abnormality, the information signal S 2 is supplied from the node 16 connected to itself, and the information is sent to one switch 21 via the protection line 81. Supply signal S2. This operation will be described in detail.

The node 16 receives the information signal S2 from the node 15 when receiving the "abnormal" line state signal E2 from the node 15 as described above. Node 16
When the information signal S2 is received from the node 15, its own display information is embedded in the received information signal S2, and the information signal S2 is supplied to the other switch 22 through the line 92. The other switch 22 converts the supplied information signal S2 into
The signal is transmitted to one switch 21 through the protection line 81.

In the embodiment, when the information signal S2 is supplied from the other switch 22, the one switch 21 supplies the information signal S2 to the node 11 connected thereto.
More specifically, when one of the switches 21 receives the information signal S2 from the other switch 22, the received information signal S2
Is supplied to the node 11 through the line 92.

In FIG. 3, of the plurality of lines 91 and 92,
Line 91 is normal. The operation relating to the line state signal U1 and the information signal S1 transmitted on the line 91 is shown in FIG.
The operation is the same as that shown in FIG.

Next, the operation and effect of the information transmission apparatus according to the present invention will be described.

A plurality of nodes 11 to 16 are connected to a plurality of lines 9
1 and 92 are sequentially connected. Each of the nodes 11 to 16 transmits an information signal S1, S2 or a line state signal U1 to each of the plurality of lines 91, 92.
(E1) and at least one of U2 (E2).
Specifically, each of the nodes 11 to 16
, The information signal S1 or the line state signal U1 (E1)
, And at least one of the information signal S2 and the line state signal U2 (E2) is supplied to the line 92. Accordingly, the line 91 is supplied with the information signal S1 and the line state signal U1 (E1), and the line 91 transmits the information signal S1 and the line state signal U1 (E1). Similarly, the information signal S2 and the line state signal U2
(E2), and the line 92 transmits the information signal S2 and the line state signal U2 (E2).

Line state signals U1 (E1), U2 (E2)
Is transmitted in a fixed direction a1, a2 in each of the plurality of lines 91, 92. Specifically, the line state signal U1 (E1) is transmitted in a certain direction a1 on the line 91, and the line state signal U2 (E2) is transmitted in a certain direction a2 on the line 92. Therefore, the line state signals U1 (E1) transmitted on the respective lines 91 and 92,
U2 (E2) is supplied to any one of the nodes 11 and 16 located at both ends.

In the embodiment, since the transmission direction a1 of the line state signal U1 (E1) is from the node 16 to the node 11, the line state signal U1 (E1) is
1 and 16 are supplied to the node 11. Further, the direction a2 in which the line state signal U2 (E2) is transmitted is the node 11
From the line state signal U2
(E2) is supplied to the node 16 of the nodes 11 and 16.

The two switches 21 and 22 are respectively connected to the nodes 1 located at both ends of the plurality of nodes 11 to 16.
1, 16 are connected. Accordingly, the above-mentioned line state signals U1 (E1) and U2 (E2) are supplied to the switch connected to the node via one of the nodes 11 and 16 located at both ends. Is done.

In the embodiment, the line status signal U1 (E1)
Is supplied to the switch 21 connected to the node 11 via the node 11. Line status signal U2 (E2)
Is supplied to the switch 22 connected to the node 16 via the node 16.

Of the two switches 21 and 22, switch 2
1 is a line state signal U from the node 11 connected to itself.
1 (E1) is supplied, and a line abnormality is detected by decoding the line state signal U1 (E1). The switch 22 is
The line state signal U2 (E
2) is supplied, and a line abnormality is detected by decoding the line state signal U2 (E2). Therefore, a plurality of lines 9
When a line abnormality such as noise intrusion or disconnection occurs in one of the lines 1 and 92, one of the two switches 21 and 22 detects the line abnormality.

In the embodiment, the switch 21 decodes the supplied line state signal U 1 (E 1) to obtain the line 9.
1 is detected. The switch 22 detects an abnormality of the line 92 by decoding the supplied line state signal U2 (E2). Accordingly, when an abnormality occurs in the line 91 as shown in FIG. 2, the switch 21 detects the abnormality in the line 91. When an abnormality occurs in the line 92 as shown in FIG. 3, the switch 22 detects the abnormality in the line 92.

The two switches 21 and 22 are connected to each other by a protection line 81. Referring to FIG. 2, one of the two switching devices 21 and 22 is
Will be described when a line abnormality is detected.

When one of the switches 21 detects a line abnormality, the information signal S 1 is supplied from the node 11 connected thereto, and the information signal S 1 is supplied to the other switch 22 via the protection line 81. I do. The other switch 22 supplies the information signal S1 to the node 16 connected thereto when the information signal S1 is supplied from the one switch 21. As described above, when a line abnormality occurs in the line 91, the information signal S
1 is connected to the other node 1 via the protection line 81 from one of the nodes 11 and 16 located at both ends.
6 is transmitted. Therefore, a detour path for the information signal S1 is formed, and information transmission can be continued.

Next, with reference to FIG. 3, a description will be given of a case where one of the two switches 21 and 22 detects a line abnormality.

When the other switch 22 detects a line abnormality, the information signal S 2 is supplied from the node 16 connected to itself, and the information signal S 2 is supplied to one switch 21 via the protection line 81. I do. One switch 21 supplies the information signal S2 to the node 11 connected to itself when the information signal S2 is supplied from the other switch 22. Thus, when a line abnormality occurs in the line 92, the information signal S
2 is one of the nodes 11 and 16 located at both ends via the protection line 81 from the other node 16.
1 is transmitted. Therefore, a detour path for the information signal S2 is formed, and information transmission can be continued.

The number of the spare lines 81 is smaller than the number of the plurality of lines 91 and 92. In the information transmission apparatus of the present invention, even if the number of the protection lines 81 is smaller than the number of the plurality of lines 91 and 92,
Information transmission can be continued when the line is abnormal.

As described above, in the conventional information transmission apparatus, a plurality of lines make a round by sequentially connecting a plurality of nodes. In this case, among the plurality of nodes, the nodes located at both ends are connected to each other by the respective lines, so that the line installation cost and the maintenance cost increase.

On the other hand, in the information transmission apparatus of the present invention,
Protection line 8 connecting nodes 11 and 16 located at both ends
1 is smaller than the number of lines 91 and 92 that sequentially connect the plurality of nodes 11 to 16. Therefore, it is possible to reduce the line installation cost and the maintenance cost.

[0073]

As described above, according to the present invention, the following effects can be obtained. (A) It is possible to provide an information transmission device that can continue information transmission when a line abnormality occurs. (B) It is possible to provide an information transmission apparatus in which the number of lines connecting nodes located at both ends among a plurality of nodes is small. (C) It is possible to provide an information transmission device capable of reducing the line installation cost and the maintenance cost.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a configuration of an information transmission apparatus according to the present invention.

FIG. 2 is a diagram illustrating a case where an abnormality occurs in one of a plurality of lines in the information transmission apparatus illustrated in FIG. 1;

FIG. 3 is a diagram illustrating a case where an abnormality occurs in another of the plurality of lines in the information transmission apparatus illustrated in FIG. 1;

[Explanation of symbols]

 91, 92 lines 11 to 16 nodes 81 protection lines 21, 22 switches S1, S2 information signals U1 (E1), U2 (E2) line status signals

Claims (3)

[Claims] 1. An information transmission apparatus including a plurality of lines, a plurality of nodes, at least one protection line, and two switches, wherein the plurality of nodes are sequentially connected to each of the plurality of lines. And each node supplies at least one of an information signal and a line state signal to each of the plurality of lines, and the line state signal is transmitted in a fixed direction on each of the plurality of lines. The at least one protection line is provided in a number smaller than the number of the plurality of lines, and the two switchers are respectively connected to each other by the protection line, and are located at both ends of the plurality of nodes. And at least one of the two switches is
The line state signal is supplied from a node connected to the self, a line abnormality is detected by decoding the line state signal, and when the line abnormality is detected, the information signal is supplied from a node connected to the self. Supplying the information signal to the other switch via the protection line, and the other switch supplies the information signal from the one switch to a node connected thereto when the information signal is supplied from the one switch. An information transmission device that supplies an information signal. 2. The information transmission apparatus according to claim 1, wherein each of the plurality of lines has a direction opposite to a transmission direction of the line state signal when the line itself is not detected as a line abnormality. An information transmission device that transmits information signals. 3. The information transmission device according to claim 1, wherein the plurality of nodes are provided at a distance from each other along a railway line.