JPS6110338A - Signal relay system by optical fiber - Google Patents

Abstract

PURPOSE:To prevent the entire system from being faulty even at disconnected cable by transmitting a signal to be transmitted to a loop transmission line possible for selecting one of two systems and selecting the systems by a switch installed on a reception point. CONSTITUTION:A connecting terminal is provided to points (a)-(j) and the connection terminals are connected in a loop by the optical fiber 1. In relaying a signal between the positions (a) and (f), a TV camera 2 and a repeater 3 are moved to the position (a), and the repeater 3 is connected to both the terminals by releasing the connection of both the terminals. Further, a TV monitor 4 and a relay circuit 5 are arranged on the position (f) and the repeater 5 is connected to both the terminals by releasing the connection of both the terminals. The repeater 3 uses a control signal from the controller 7 to select one of two terminals and transmits a signal. The repeater 5 uses the control signal similarly to select the line transmitted from the point (a) and then receives a signal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is suitable for use in information transmission systems that transmit image signals using optical fibers. In particular, the present invention relates to an information transmission system for preventing transmission path failures.

[Conventional technology]

In a conventional information transmission system, when an optical fiber cable is used as an image transmission path, a television camera 101 and a television monitor 104 are connected to an electro-optic converter 102 and an opto-electric converter 103, as shown in FIG. A multi-core optical fiber cable 105 is used to connect the optical fibers. One spare core optical fiber 105b is prepared separately from the signal transmission line core fiber 105a in the same optical fiber cable 105, and when the current core fiber 105a is cut, it is switched to the spare core optical fiber 105b. Prepare for failure by doing this.

However, when the optical fiber cable itself is cut, it has the disadvantage that all transmission systems using the cable become unusable. Also, since there is a one-to-one correspondence between sending and receiving,
It also has the disadvantage that it is not easy to install, expand, or remove terminals and lacks flexibility.

[Problem that the invention seeks to solve]

The present invention solves the above problems, and aims to provide an information transmission system that does not cause system downtime even when a cable is cut, allows easy addition and removal of terminals, and allows quick recovery.

[Means for solving problems]

The present invention transmits a signal to be transmitted to a loop-shaped transmission line in which one of two systems can be selected by a switch,
It is characterized by being selected by a switch installed at the receiving location.

〔Example〕

FIG. 1 is a block diagram of an embodiment of the present invention. In this example, a connection terminal is provided at each of the 10 points a-%-3,
The optical fiber 1 is laid so that the optical fiber 1 connects the connection terminals in a loop. In this optical fiber relay line, both terminals are connected to each other when the terminals at each point are not in use so that signals can be transmitted in a loop.

Now, to explain the case where a signal is relayed between position la and position f using this relay line, the television camera 2 and relay device 3 are moved to position a, and the connection between both terminals is released. A relay device 3 is connected to both terminals. Furthermore, a television monitor 4 and a relay circuit 5 are placed at position f, and both terminals are disconnected and a relay device 5 is connected to both terminals.

Further, in this example, a control signal is supplied from one control device 7 to two relay devices 3 and 5 via another electric signal wA6. This electric signal line 6 can be provided temporarily when transmitting and receiving control signals using, for example, a telephone line.

The relay device 3 selects one of the two terminals based on this control signal and transmits the signal. Similarly, the relay device 5 selects the line on which the signal is being transmitted from point a based on this control signal, and receives the signal.

When relay transmission is being performed by selecting the line that passes through point i, there is a failure in the line at the point marked with an x.

If this occurs, the line passing through point i will be disconnected, but since the line passing through point C is independent of this, there will be no failure, and by switching the connection at relay devices 3 and 5, , relay transmission can be continued.

FIG. 3 is a block diagram of the device at point a, where (a) shows the case where switching is performed using an electrical signal, and (b) shows the case where switching is performed using an optical signal. Figure 4 is a configuration diagram of the device at point f, (a)
(b) is a case where switching is performed using an electrical signal, and (b) is a case where switching is performed using an optical signal. In Fig. 3, 31 is a video signal switching circuit;
32 is an electro-optical converter. 33 is an electro-optical converter;
34 is an optical signal switching circuit. In FIG. 4, 51 is a photoelectric converter, and 52 is a video signal switching circuit. Further, 53 is an optical signal switching circuit, and 54 is a photoelectric converter. The present invention can be practiced in any form.

〔Effect of the invention〕

As explained above, according to the present invention, even if there is a failure in a relay line, it is often possible to switch the line and continue relaying without immediately disabling the entire relay. This has the advantage of improving customer service. Furthermore, it is more economical than the case where separate lines are provided for each relay position. Another advantage is that it is possible to flexibly add or remove five relay points.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention. FIG. 2 is a configuration diagram of the embodiment system. FIG. 3 is a diagram showing an example of the equipment configuration at point a. FIG. 4 is a diagram illustrating an example of the configuration of the equipment at the location. 1... Optical fiber, 2... Television camera, 3
...Relay device, 4...Television monitor, 5...
・Relay device, 6... Separately provided electric signal line, 7...
·Control device.

Claims (1)

[Claims] (1) Using optical fibers installed in advance at three or more points, provide connection terminals to the optical fibers at each of the points, move the relay device to any of the points, and connect the connection terminals to the relay device. In this method, the optical fibers are laid so as to connect the three or more points mentioned above in a loop, and each of the above points is connected to each point connected to two different points. The above-mentioned connection terminals are provided at each terminal of the optical fiber, and the above-mentioned connection terminals are connected to each other at points where the above-mentioned repeating equipment is not connected, and when the repeating equipment is connected, the connections are released and the above-mentioned connections are made via a selection switch. A signal relay method using optical fiber, which is characterized by transmitting and receiving relay signals to and from terminals.