JP2533798Y2 - Fault monitoring system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fault monitoring system, and more particularly to an optical terminal having a function of monitoring a fault with a digital line link having a line section connected in tandem. The present invention relates to a fault monitoring system having a device.

[Conventional technology]

FIG. 3 shows a conventional digital line link. The digital line link L has a configuration in which a plurality of digital line sections S are connected in tandem. Where each digital line section S
Are optical terminal devices 11 arranged at both ends thereof, and some optical repeaters for transmitting bidirectional signals between them.
It is composed of 12 and. Each optical terminal unit has a monitoring function in the digital line section S to which it belongs, but cannot monitor other digital line sections connected in tandem. Therefore, in order to monitor each digital line section S constituting the digital line link L, a dedicated monitoring device 13 is arranged so as to connect adjacent digital line sections S. Was.

[Problems to be solved by the invention]

As described above, the conventional optical terminal unit has a monitoring function only in the digital line section S to which the optical terminal unit belongs.
It was necessary to arrange a dedicated monitoring device as shown in the figure at the station where the optical terminal equipment was installed. For this reason, there is a problem that the system becomes large-scale and the cost required for the system increases.

Therefore, an object of the present invention is to provide a fault monitoring system that enables monitoring within a digital line link without arranging a special monitoring device at an installation station of an optical terminal device.

[Means for solving the problem]

In the present invention, a digital line link is formed by connecting a plurality of digital line sections in tandem, and each digital line section has one at each end.
In a communication system in which optical terminal devices are arranged one by one, and an optical repeater for transmitting an optical signal in both directions is arranged between the pair of optical terminal devices in the same digital line section, Each optical terminal equipment has (a) a fault monitoring unit for monitoring a fault in its own digital line section, and (b) converting an optical signal received by an optical repeater into an electric signal and vice versa. An electrical-optical conversion circuit that converts an electrical signal into an optical signal and sends it to an optical repeater; and (c) an electrical signal converted by the electrical-optical conversion circuit, a fault transmitted from its own fault monitoring unit. Insert service data consisting of fault service data representing information and polling service data representing the address of a failure collection destination, and send this to an adjacent digital line section;
A signal converter for extracting service data from the electric signal sent from the adjacent digital line section; and (d) connected between the adjacent digital line sections, and when polling service data arrives from the signal converter, this is transmitted. When the address is compared with the address assigned to the digital line section, the monitoring result is input from the fault monitoring unit to the signal converter, and when the address does not match, the polling service data is transmitted. And a selector circuit for transmitting the signal to an adjacent digital line section.

That is, in the present invention, the fault monitoring unit collects fault information in the same digital line section, and when polling is performed from another digital line section, polling service data indicating the address of the target digital line section is generated. It is taken out from the signal converter and compared with its own address. If the addresses match, the monitoring result from its own fault monitoring unit is input to the signal converter and transmitted to another digital line section, while the address is one. If not, the polling service data is sent to the adjacent digital line section, thereby achieving the above object.

〔Example〕

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

FIG. 2 shows a digital line link using an optical terminal device according to an embodiment of the present invention. Each digital line section S is constituted by an optical terminal device 21 disposed at each end of the digital line section S, and an optical repeater device 12 for transmitting signals bidirectionally therebetween.

FIG. 1 specifically shows a part of the digital line link shown in FIG. In this figure, two optical terminal units 21N and 21 (N + 1) belong to the same digital line section S. The optical terminal device 21 (N + 2) arranged opposite to the optical terminal device 21 (N + 1) belongs to the digital line section adjacent thereto.

Each optical terminal device 21 includes a signal conversion circuit 23,
An optical conversion circuit 24, a selector circuit 25, and a fault monitoring circuit 26 are provided. Here, the signal conversion circuit 23 uses CEPT (Conferen
ce of European Posts and Telecommunication) Hierarchy A-bit / second signal (first signal), frame synchronization signal and B-bit / second service data signal (second signal), C-bit and D-bit / second A circuit function of inserting a second service data signal (third signal) as an overhead bit and converting it into an F bit / second signal (fourth signal); This is a circuit having a function of extracting signals of seconds, B bits / second and D bits / second.

The electric / optical conversion circuit 24 is a circuit for converting a signal of F bits / second from an electric signal to an optical signal and from an optical signal to an electric signal. Further, the fault monitoring circuit 26 constantly monitors the fault status of the device, and reports this to the boring service data.
This is a circuit that outputs the data on both the bit 27 and the bit multiplexing service data 28. Here polling service data 27
Is data for collecting fault information of a digital line section connected in tandem by a polling method, and the bit multiplexing service data 28 is bit multiplexing for collecting fault information of each device in each digital line section. Service data and is terminated at each digital line section. The selector circuit 25 has an address number, and when its own address number is called through the polling service data 27, the polling service data 27 is connected to the fault monitoring circuit 26 side,
When it is different from its own address number, this polling service data 27 is connected to the optical terminal equipment side of the next digital line section.

Next, the operation of the optical terminal device having the above configuration will be described.

Now, it is assumed that the optical terminal device 21 (N + 1) in FIG. 1 is called by a polling method. Optical terminal equipment 21 (N +
2) The selector circuit 25 is provided with polling service data 27.
And compare it with your address number. In the case of this example, since this does not coincide with its own address number, the polling service data 27 is sent to the selector circuit 25 of the optical terminal unit 21 (N + 1) of the adjacent digital line section S.

Upon receiving the polling service data 27, the selector circuit 25 of the optical terminal station device 21 (N + 1) compares it with its own address number. Since the address numbers match, the selector circuit 25 of the optical terminal device 21 (N + 1) outputs the polling service data 27 to its own fault monitoring circuit 26. The failure monitoring circuit 26 of the optical terminal equipment 21 (N + 1)
The failure information of the digital line section S sandwiched between the optical line terminal 21N and the optical terminal unit 21 (N + 1) is collected by the bit multiplexing service data 28. The optical terminal equipment 21
The (N + 1) fault monitoring circuit 26 supplies this fault information to its own selector circuit 25 at this point in time when the polling service data 27 is input. The selector circuit 25 supplies this to its own signal conversion circuit 23.

The signal conversion circuit 23 of the optical terminal device 21 (N + 1) creates a signal of F bits / sec into which the polling service data 27 is inserted, and sends it to the signal conversion circuit 23 of the optical terminal device 21 (N + 2). Send to In this way, the optical terminal equipment
The failure information output from 21 (N + 1) is
(N + 2) signal conversion circuit 23 and electric / optical conversion circuit 24
Will be transmitted through.

[Effect of the invention]

As described above, according to the present invention, since the optical terminal equipment itself is provided with the tandem line monitoring function, the digital line link in which a plurality of digital line sections are connected to the tandem in a small system configuration. Monitoring can be performed, and the cost required for monitoring can be reduced.

[Brief description of the drawings]

FIGS. 1 and 2 are diagrams for explaining an embodiment of the present invention. FIG. 1 is a circuit diagram showing a circuit configuration of a part of an optical terminal device constituting a digital line link. FIG. 2 is a configuration diagram of a digital line link, and FIG. 3 is a configuration diagram of a digital line link using a conventional optical terminal device. 12 ... optical repeater, 21 ... optical terminal equipment, 23 ... signal conversion circuit, 24 ... electric / optical conversion circuit, 25 ... selector circuit,
26: Fault monitoring circuit, L: Digital line link, S
...... Digital line section.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-64-10752 (JP, A) JP-A-62-51321 (JP, A) JP-A-61-199953 (JP, U)

Claims (1)

(57) [Scope of request for utility model registration] 1. A digital line link comprising a plurality of digital line sections connected in tandem. Each digital line section is provided with one optical terminal device at each end. A communication system in which an optical repeater for transmitting an optical signal in both directions is arranged between the pair of optical terminal devices, and each optical terminal device has a failure in its own digital line section. A fault monitoring unit for monitoring, and an electro-optical conversion circuit that converts an optical signal received by the optical repeater into an electrical signal, or conversely converts the electrical signal into an optical signal and sends the optical signal to the optical repeater And fault service data and fault collection destinations indicating fault information sent from its own fault monitoring unit to the electric signal converted by the electric / optical conversion circuit. Signal conversion which inserts service data consisting of polling service data representing the address of the above and sends it to an adjacent digital line section, and extracts the service data from an electric signal sent from the adjacent digital line section And the adjacent digital line sections are connected to each other. When the polling service data arrives from the signal converter, the polling service data is compared with an address assigned to its own digital line section. A selector circuit for inputting the monitoring result from the monitoring unit to the signal converter, and transmitting the polling service data to the adjacent digital line section when the addresses do not match. Fault monitoring Stem.