JPH0327055B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a disconnection detection device for an optical fiber cable for information transmission, and in particular to a self-supporting type device in which an optical fiber cable body and a messenger wire are combined with a binding wire. Concerning what is used for optical fiber cables.

BACKGROUND TECHNOLOGY As is well known, as an information transmission system using optical fiber cable, as shown in Fig. 5,
An optical fiber cable body 11 for information transmission, a messenger wire 12 installed overhead, for example between steel towers (not shown), and a bind wire 13 formed by insulating a conductor wire 13a are wound and combined to form a so-called self-contained cable. Some systems use supported fiber optic cables to enable long-distance installations.

Problems to be Solved by the Invention By the way, in an information transmission system using a self-supporting optical fiber cable as described above, when a received signal is interrupted, it is difficult to determine whether the cause is a break in the optical fiber cable or not. In order to determine whether there is a failure in the equipment, conventional methods have been used to detect breaks in the optical fiber cable by connecting the optical fiber cable to an optical fiber failure point locating device, sending out optical pulses and receiving the reflected light. This is done by detecting the presence or absence of.

However, with such conventional means, it takes a lot of man-hours and is very time-consuming from the time the received signal of the information transmission system is interrupted until the time when the optical fiber cable is detected for disconnection and the cause of the received signal is interrupted. This problem arises.

The present invention has been made in consideration of the above circumstances, and provides an extremely good disconnection detection device for self-supporting optical fiber cables that can easily detect disconnections in self-supporting optical fiber cables with a simple configuration. The purpose is to

Means for Solving the Problems That is, the disconnection detection device for a self-supporting optical fiber cable according to the present invention uses a binder for combining an optical fiber cable main body for information transmission with an overhead messenger wire. As the wire, an electric wire made of a plurality of conductor wires coated with insulation is used. A closed circuit is constructed using a plurality of conductor wires of this electric wire, and a current for detecting disconnection is passed through this closed circuit, and a disconnection of the self-supporting optical fiber cable is detected based on the presence or absence of the current. It is.

In other words, when the self-supporting optical fiber cable is disconnected, the electric wire is also disconnected, so the current for disconnection detection that flows through the closed circuit made up of multiple conductor wires becomes zero. By detecting this, it is possible to detect a break in the self-supporting optical fiber cable.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. That is, as shown in FIG. 2, the optical fiber cable main body 14 for information transmission
A plurality of (two in the illustrated case) binding wires are used as binding wires to connect the wires and the messenger wires 15 installed overhead, for example between the steel towers (not shown).
An electric wire 16 is used, which is formed by insulatingly covering conductor wires 16a and 16b.

First, as shown in FIG. 3, both ends of the optical fiber cable main body 14 are connected to optical transmission devices 17 and 18 that have information signal transmission and reception functions, and information is transmitted between the two optical transmission devices 17 and 18. Transmission is allowed to take place.

Further, each conductor wire 16a, 16b of the electric wire 16
Both ends of are connected to disconnection detection circuits 19 and 20, respectively. Among these, disconnection detection circuit 19
As shown in FIG. 1, the DC power supply 22 has the conductor wire 16a connected to the positive side and the conductor wire 16b connected to the negative side via the ammeter 21, and the measured value of the ammeter 21 is displayed. The display circuit 23 includes a display circuit 23. In addition, the disconnection detection circuit 20
The ammeter 24 includes conductor wires 16a and 16b connected to both input ends thereof, and a display circuit 25 that displays the measured value of the ammeter 24.

That is, each of the conductor wires 16a and 16b is configured to form an electrically closed circuit by the disconnection detection circuits 19 and 20.

Therefore, when the optical fiber cable main body 14 is not disconnected, that is, when the electric wire 16 is not disconnected, the conductor wires 16a, 16b are not connected to each other as shown in FIG.
This means that a constant current I determined by the electrical resistance between b and the ammeters 21 and 24 is constantly flowing. In this state, if the optical fiber cable main body 14 is disconnected at time T, the electric wire 16 is also disconnected, so the constant current I no longer flows through the conductor wires 16a and 16b, and at this time the display circuit 23, The indicated value of No. 25 becomes zero, and a break in the optical fiber cable is detected at this point.

Moreover, in the above, the optical fiber cable main body 14
Although the detection has been described in the case where the optical fiber cable 14 is disconnected, for example, even if the messenger wire 15 is disconnected without the optical fiber cable 14 being disconnected, the disconnection can be detected because the electric wire 16 is disconnected. In other words, in a self-supporting optical fiber cable that is installed overhead, it is necessary to determine that there is a failure even if the optical fiber cable main body 14 is not disconnected and only the messenger wire 15 is disconnected. Therefore, as described above, it is important to be able to detect the disconnection even if either the optical fiber cable main body 14 or the messenger wire 15 is disconnected. It is very suitable for cables.

Furthermore, in order to combine the optical fiber cable main body 14 and the messenger wire 15, the conventionally used binding wire is replaced with an electric wire, so there is no need to attach a new wire to the optical fiber cable. Because there is no increase in weight,
In this respect as well, it is very suitable for self-supporting optical fiber cables installed overhead.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and can be implemented with various modifications without departing from the gist thereof.

Effects of the Invention Therefore, as detailed above, according to the present invention, a break in a self-supporting optical fiber cable can be easily detected with a simple configuration, and a break in the self-supporting optical fiber cable can be easily detected. A detection device can be provided.

[Brief explanation of drawings]

FIG. 1 is a block configuration diagram showing an embodiment of a self-supporting optical fiber cable disconnection detection device according to the present invention, and FIG. 2 is a configuration diagram showing details of an electric wire as a binding wire used in the same embodiment. , FIG. 3 is a block configuration diagram for explaining the overall operation of the same embodiment, FIG. 4 is a characteristic diagram for explaining the disconnection detection operation of the same embodiment, and FIG. 5 is a diagram showing the conventional binding wire. FIG. 11...Optical fiber cable body, 12...Messenger wire, 13...Binding wire, 14...
... Optical fiber cable body, 15 ... Messenger wire, 16 ... Electric wire, 17, 18 ... Optical transmission device, 19, 20 ... Disconnection detection circuit, 21 ... Ammeter, 22 ... DC power supply, 23 ...Display circuit, 2
4... Ammeter, 25... Display circuit.

Claims (1)

[Claims] 1. In a self-supporting optical fiber cable formed by combining an optical fiber cable body for information transmission and a messenger wire by wrapping a bind wire around the cable, the bind wire may be an electric wire formed by insulating a plurality of conductor wires. A closed circuit is constructed using a plurality of conductor wires of the electric wire, and a current for detecting disconnection is passed through the closed circuit, and a disconnection of the self-supporting optical fiber cable is detected based on the presence or absence of the current. Disconnection detection device for self-supporting optical fiber cable.