JP2679675B2 - Terminal malfunction prevention circuit in loop type transmission line - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a malfunction prevention circuit for a terminal device, and more particularly to a device in which the network structure of a duplicated transmission path should be a loop type, and in particular, when a loop structure is not adopted, a failure due to a line disconnection occurs The present invention relates to a device that prevents a malfunction of a terminal device in the event of an occurrence or a failure involving a line disconnection occurring in two or more locations at the same time.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 4, a loop (closed loop) type optical communication device of this type has, for example, a node on a duplicated transmission line 100-1 and 100-2 whose transmission directions are opposite to each other. 1-1
From 1 to 6 multiple nodes are connected. Further, in FIG. 4, the terminal device 2 is connected to the node 1-1 for explanation.
-1 is connected, and the terminal device 2-2 is connected to the node 1-4.

Referring to FIG. 8, the node 1-1 is composed of a transmission line terminating unit 10 terminating the duplicated transmission lines 100-1 and 100-2, and a terminal data processing unit 11. Part 11
Receives data from the terminal device 2-1 and sends it to the transmission line 100-1 via the transmission line terminating unit 10 and processes a signal input from the transmission line 100-2 via the transmission line terminating unit 10. Output to the terminal device 2-1. The nodes 1-4 in FIG. 4 have the same configuration.

FIG. 5 shows a loop configuration in which the network configuration is incomplete, and data transmission is performed as follows between the nodes 1-1 to 1-6 in the network thus configured.

That is, the data transmitted from the terminal device 2-1 to the terminal device 2-2 is transmitted through the route of node 1-1 → 1-2 → 1-3 → 1-4.

In the transmission path through which data is transmitted in this way, for example, as shown in FIG. 6, when a failure occurs due to disconnection in the transmission path between the node 1-3 and the node 1-4, In the conventional recovery measure against a transmission line failure, the loopback switching is performed so that the transmission line 100-1 is looped back to the transmission line 100-2 at the node 1-3.

Therefore, the data transmitted from the terminal device 2-1 is looped back at the node 1-3, and the node 1-1 → 1-2.
→ 1-3 → 1-2 → 1-1 → 1-6 → 1-5 → 1-6 → 1-1 It returns through the loop.

Further, as shown in FIG. 7, when a failure occurs simultaneously in the transmission lines between the nodes 1-3 and 1-4 and between the nodes 1-4 and 1-5, the node 1 -Transmission line 100 at -3
The loopback is switched so that -1 is returned to the transmission path 100-2, and the loopback is switched so that the transmission path 100-2 is returned to the transmission path 100-1 at the node 1-5. Therefore, the data transmitted from the terminal device 2-1 is node 1-1 → 1-
It returns through the route of 2 → 1-3 → 1-2 → 1-1 → 1-6 → 1-5 → 1-6 → 1-1.

[0009]

In the conventional loop type optical communication device, as shown in FIG. 6, when a failure occurs in the transmission line between the node 1-3 and the node 1-4, Loopback switching is performed at 1-3, and as shown in FIG. 7, the transmission line between the node 1-3 and the node 1-4 and the node 1-
If a failure occurs simultaneously with line disconnection in the transmission line between node 4 and node 1-5, node 1-3 switches the loopback so that transmission line 100-1 loops back to 100-2. The loopback is switched so that the transmission line 100-2 is folded back to 100-1 at -5.

As a result, the nodes 1-4 are in a disconnected state in which data communication cannot be performed with other nodes.

Here, assuming that the node 1-1 and the node 1-4 are communicating data, the data from the node 1-1 is not transmitted to the node 1-4 and the node 1-1 is directly transmitted. Transmitted to.

That is, in the node 1-1, since the transmission data of itself inserted in the preset time slot returns without being extracted by the node 1-4, the data transmitted by the terminal device 2-1 itself Will be received. Therefore, there is a problem in that the terminal device 2-1 that has received its own transmission data recognizes this received data as invalid data, and thus the data communication of the terminal device 2-1 falls into an abnormal state.

Therefore, the present invention has been made in view of the above problems, and when data is transmitted to a node which cannot communicate due to a failure at the time of loopback due to the failure of the transmission path, the terminal which is transmitting the data. An object of the present invention is to provide a system and a device that prevent the device from falling into an abnormal state.

[0014]

Means for Solving the Problems] To achieve the above object, the present invention is a network configuration of the loop, Den
On a transmission line in which transmission direction is duplicated in the reverse direction, and transmitting information processing means, a receiving information processing means, comprising a plurality of nodes having, in a transmission system wherein the node ing comprises a loopback function, One Node adds a predetermined dummy signal to a transmission signal from one terminal device connected to the node and transmits the signal to another terminal device connected to another node via the transmission line, and the one node separating the dummy signal from the received signal, compared with the dummy signal a dummy signal said separated was added to the transmission signal, based on the comparison result, the received main signal transmission of the to one terminal
Controls the permission / prohibition, provides lockout scheme of the terminal device, characterized in that.

In the present invention, preferably, when the two dummy signals coincide with each other, it is judged that the other node is in a state of being disconnected from the network at the time of loopback due to a transmission path failure, and received. It is characterized in that the main signal is controlled so as to be prohibited from being transmitted to the one terminal device.

Further, the present invention is a node having a loop type network configuration having two transmission directions opposite to each other and having signaling transmission information processing means and signaling reception information processing means on the duplex transmission path. In a transmission system comprising a plurality of, the node has a transmission line terminating unit that terminates the duplexed transmission line, and a terminal data processing unit, and the terminal data processing unit has one input terminal from a terminal device. A multiplexing unit for inputting a signaling transmission signal, inputting a first dummy signal to the other input end, multiplexing these signals and outputting the multiplexed signal to the transmission line terminating unit,
A demultiplexing unit that inputs data from the transmission line terminating unit and separates and outputs a signaling reception signal at one output end and a second dummy signal at the other output end; and the first and second dummy A signal is input, and a comparator that detects the coincidence of the two dummy signals and an output signal of the comparator are used as control inputs, and the transmission of the main signal input from the transmission line termination unit to the terminal device is controlled. A malfunction prevention circuit for a terminal device, comprising: a control unit.

In the present invention, preferably, the control unit transmits the main signal input from the transmission line termination unit to the terminal device when a signal indicating that the comparison result of the comparator indicates coincidence is output. Characterized by prohibition.

[0018]

According to the present invention, a dummy signal is added to the transmission data from the terminal device, the returned dummy signals are compared, and the terminal data to the terminal device is controlled according to the comparison result, so that the transmission path failure is prevented. It is possible to prevent the terminal device from falling into an abnormal state when data is transmitted to a node that cannot perform data communication during loopback due to occurrence.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

5 and 6 are network configuration diagrams for explaining an embodiment of the present invention. FIG. 5 shows an incomplete loop state, where the transmission line 100-1 is the node 1-4 and the transmission line 10
Loopback connection to 0-2. Further, FIG. 6 shows a case where a failure accompanied by a line disconnection occurs at two locations at the same time, and the transmission path 100-1 is the node 1-3 to the transmission path 100-2.
00-2 is loopback-connected to the transmission line 100-1 at node 1-5. The terminal devices 2-1 and 2-2 are connected to the nodes 1-1 and 1-4, respectively.

FIG. 1 shows a node in one embodiment of the present invention.
FIG. 6 is a diagram showing a configuration of 1-1 and 1-4 (see FIG. 5), and shows a configuration of a terminal data processing unit 11 forming a main part of the present invention in a block diagram.

Referring to FIG. 1, a terminal data processing device 11 of a node multiplexes signaling transmission information S / S1 from a terminal device (not shown) and a first dummy signal and outputs the multiplexed signal to a transmission line terminating unit 10. The received signal from the multiplex unit (MUX) 110 and the transmission line terminating unit 10 is set as the signaling reception information S.
/ R2 and a second dummy signal for demultiplexing unit (DMUX) 113, a first dummy signal and a second dummy signal for comparing (CMP) 114, and a comparator (CMP) The control unit (INH) 115 controls the permission / prohibition of the supply of the main signal to the terminal device (not shown) using the comparison result output of 114 as a control input.

The configuration and operation of the terminal device processing section according to the embodiment of the present invention will be described with reference to FIG. In the terminal data processing unit 11 of the node 1-1 of FIG.
The terminal device 2-2 is connected to the terminal data processing units 11 'of 1-4 (see FIG. 5).

Referring to FIG. 2, in node 1-1, signaling transmission information S / S1 from the terminal device 2-1 side is sent.
(A) and the first dummy signal (b) are multiplexed by the multiplexing unit (MUX) 110 and sent to the transmission line via the transmission line terminating unit 10. At the nodes 1-4, the demultiplexing unit (DMUX) is used. ) Signaling reception signal S / R1 at 111
(E) is separated from the first dummy signal (f), and the signaling reception information S / S2 (g) from the terminal device 2-2 side and the second dummy signal (h) are multiplexed into the multiplexing unit (MUX).
The data is multiplexed at 112 and sent to the transmission line via the transmission line terminating unit 10 '. In node 1-1, demultiplexer (DM
The UX) 113 separates the signaling reception information S / R2 (k) from the second dummy signal (1), and the comparator (CMP) 11
Reference numeral 4 compares the first dummy signal (b) added at the time of transmission with the second dummy signal (1) returned, and the control unit (INH) 115 outputs the comparison output from the comparator (CMP) 114. Based on the result, the main signal (m) to the terminal device is controlled.

Next, the operation of the terminal data processing section 11 will be described in more detail. Usually the first dummy signal (b)
And the second dummy signal (1) are preset to signal values that do not match each other. In the present embodiment, for the sake of explanation, the first dummy signal (b) is set to "L" level and the second dummy signal (l) is set to "H" level.

In the node 1-1, the signaling transmission information S / S1 (a) from the terminal device is multiplexed with the first dummy signal (b) by the multiplexing unit (MUX) 110 (time division multiplexing), It is transmitted to the transmission line terminating unit 10 as signaling S / T (c). That is, as shown in FIG.
The signaling S / T (c) is composed of a frame bit (F), signaling transmission information (S / S), and a first dummy signal of "L" level.

In the transmission line terminating unit 10, the main signal (n) and the signaling S / T (c) from the terminal device are set in advance in a preset time slot (TS M) as shown in FIG. 3 (A).
And send it to the transmission line.

In the transmission line terminating unit 10 'of the node 1-4, as shown in FIG. 3B, data is extracted from the preset time slot (TS M), and as shown in FIG. Main signal (o) and signaling S / T to terminal device
Separate (d).

In the terminal data processing unit 11 'of the nodes 1-4,
The demultiplexing unit (DMUX) 111 receives the received signaling S / T signal (d), and receives the signaling reception signal S /
R1 (e) and the first dummy signal (f) are separated. In addition, the signaling transmission signal S / S2 is sent to the node 1-1.
(G) and the second dummy signal (h) of "H" level are multiplexed by the multiplexing unit (MUX) 112 and transmitted to the transmission line terminating unit 10 'as signaling S / T (i).

In the transmission line terminating unit 10 ', the main signal (p) and the signaling S / T (i) from the terminal device are sent to the node 1-1.
Data is inserted into a time slot (TSM) (see FIG. 3C) that is vacant as a result of extracting the data of
Nodes in frame format as shown in FIG.
Send to 1-1.

In the transmission line terminating unit 10 of the node 1-1, as shown in FIG. 3 (E), the data of the preset time slot (TS M) is extracted, and the main signal (m ) And signaling S / T (j) are separated.

In the terminal data processing unit 11 of the node 1-1, the signaling S / T (j) returned from the node 1-4 is sent.
Is separated into a signaling reception signal S / R2 (k) and a second dummy signal (l) by a demultiplexing unit (DMUX) 113.

The S / T sent back from the comparator (CMP) 114 as the first dummy signal (b) added at the time of transmission.
The second dummy signal (l) in the signals is compared.

Here, if the terminal data signal is normally transferred at the nodes 1-4, the second dummy signal (1) returned is at the "H" level, and therefore the comparator. The comparison result in (CMP) 114 shows disagreement,
Based on the comparison result, the control unit (INH) 115 permits the returned main signal (m) to be transmitted to the terminal device.

As shown in FIG. 6, in the state where the nodes 1-4 are disconnected due to the transmission line failure, the transmitted signaling reception signal S / S1 (a) and the first dummy signal (b) inserted at the time of transmission are transmitted. Returns to the predetermined time slot as it is, the comparator (CMP) 114 detects the coincidence of the two dummy signals, and the control unit (INH) 115 is transmitted based on the comparison result. The transmission of the main signal (m) to the terminal device is prohibited, and a non-permission signal (for example, all bits are “1” etc.) is transmitted to the terminal device.

In this way, the transmission side main signal (n),
A malfunction of the terminal device due to the same reception side main signal (m) is avoided.

Although the present invention has been described with reference to the above embodiments, the present invention is not limited to only the above embodiments.
Needless to say, various modes according to the principle of the present invention are included. For example, the present invention is not limited to optical communication and is applied to a transmission system having a duplicated transmission line of a loop type network configuration and having a loopback configuration at the time of a transmission line failure.

[0038]

As described above, according to the present invention,
A loopback due to a transmission line failure is configured by adding a dummy signal to the data from the terminal device, comparing the returned dummy signals, and controlling the position of the terminal data to the terminal device based on the result. At times, it is possible to prevent the terminal device from entering an abnormal state when data is transmitted to a node that cannot perform data communication.

[Brief description of the drawings]

FIG. 1 is a diagram showing a block configuration of a node according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an operation of a terminal device processing unit according to an embodiment of the present invention.

FIG. 3 is a frame format diagram in a transmission path.

FIG. 4 is a block diagram of a conventional system.

FIG. 5 is a system configuration diagram for explaining a loop configuration in which the network configuration is incomplete.

FIG. 6 is a system configuration diagram for explaining an operation when a transmission line disconnection failure occurs.

FIG. 7 is a system configuration diagram for explaining an operation when a transmission path failure occurs at two or more locations at the same time.

FIG. 8 is a block configuration diagram in a node.

[Explanation of symbols]

 1-1 to 1-6 Node 10 Transmission line termination unit 11 Terminal data processing unit 100-1, 100-2 Transmission line 110, 112 Multiplex unit (MUX) 111, 113 Demultiplex unit (DMUX) 114 Comparator ( CMP) 115 Control unit (INH)

Claims (4)

(57) [Claims] 1. A loop type network configuration for transmission
On a transmission line where the direction is duplicated in the reverse direction, and transmitting information processing means, a receiving information processing means, comprising a plurality of nodes having, in a transmission system wherein the node ing comprises a loopback function, one A node adds a predetermined dummy signal to a transmission signal from one terminal device connected to the node and transmits it to another terminal device connected to another node via the transmission path, and the one node receives Before separating the dummy signal from the generated signal and adding the separated dummy signal to the transmission signal
Serial comparison with dummy signals based on the comparison result, controls the permission / prohibition of the transmission to the one terminal of the received main signal, malfunction prevention method of a terminal device, characterized in that. 2. When the two dummy signals match each other, it is determined that the other node is in a state of being disconnected from the network at the time of loopback due to a transmission path failure, and the one of the received main signals is determined. controls to prohibit the transmission to the terminal device, the malfunction prevention method of a terminal apparatus according to claim 1, wherein a. 3. A loop type network configuration having two transmission directions opposite to each other, and a plurality of nodes each having a signaling transmission information processing means and a signaling reception information processing means are provided on a duplex transmission path. , The node
In but the transmission system comprises a loop-back function ing, the node, the line termination unit for terminating the duplicated transmission path, comprising: a terminal data processing unit, wherein the terminal data processing unit is one of A multiplexing unit for inputting a signaling transmission signal from a terminal device to an input end, inputting a first dummy signal to another input end, multiplexing these signals and outputting the multiplexed signal to the transmission line terminating unit; A demultiplexing unit for inputting data from the path terminating unit and separately outputting a signaling reception signal at one output end and a second dummy signal at the other output end, and the first and second dummy signals. A comparator for inputting and detecting the coincidence of the two dummy signals, and a control unit for controlling the transmission of the main signal input from the transmission line termination unit to the terminal device by using the output signal of the comparator as a control input. And A malfunction prevention circuit for a terminal device characterized by the above. 4. The control unit prohibits transmission of the main signal input from the transmission line termination unit to the terminal device when the comparison result output from the comparator indicates a match. Item 3. A malfunction prevention circuit for a terminal device according to item 3.