JPS61281647A - In-house information transmitting system - Google Patents

Abstract

PURPOSE:To transmit the different terminal information by a small number of the cable wiring by connecting in a loop shape plural terminal signal multiplexing devices to multiplex, transmit and receive the information from the terminal, and at least one loop synchronizing control device with the optical fiber cable of at least two cores. CONSTITUTION:A loop control device 10 and plural terminal signal multiplexing devices 20, in which plural terminals are respectively connected, are connected in a loop shape by the same optical fiber cable 100. In a terminal signal multiplexing device 20, the signal from the terminal such as a data terminal 200 is multiplexed by a multiplexing part and transmitted by the optical fiber cable 100 to an opponent terminal signal multiplexing device 20 determined beforehand. In a loop synchronizing control device 10, a time division multiplexed transmitting frame to obtain the synchronization of the signal from respective terminal signal multiplexing devices 20 is generated by the loop synchronizing control part, and transmitted to respective terminal signal multiplexing devices 20. Thus, the cable wiring is minimized and the influence of the external noise and the thunder can be prevented.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention connects computers, data terminals, telephone terminals, facsimile terminals, image terminals, etc. that are installed dispersedly within a premises, and multiplexes their signals. This paper relates to a system for transmitting in-house information in the form of digitized data.

〔overview〕

The present invention provides a local information transmission system that transmits multiple pieces of information from multiple terminals, which includes multiple terminal signal multiplexers that multiplex and transmit/receive information from the terminals, and at least one that creates and transmits a loop synchronization signal. By connecting one loop synchronous control device in a loop with at least two fiber optic cables, it is possible to transmit information from different terminals with less cable wiring.

[Conventional technology]

Conventionally, this type of local information transmission system has often configured separate systems for each type of information, and the system that connects computers and data terminals and transmits information uses local modems or optical modems, and each It is common to connect devices individually using metal cables or optical fiber cables, and private branch exchanges, telephones, facsimiles, etc. are connected directly to each other using metal cables, and image terminals and video terminals are also connected using coaxial cables. In many cases, devices are directly connected to each other.

[Problem that the invention seeks to solve]

The conventional in-premises information transmission method described above has a system configuration in which devices are individually connected to each other using metal cables, coaxial cables, or optical fiber cables, so as the number of terminal devices increases, Cable wiring work is increasing, and it is necessary to install many different types of cables for each type of information, and when you add up the conduit work, installation work, and cable costs required for cable installation, the cost becomes extremely high. There is a drawback. Furthermore, in high-rise buildings, the size of cable ducts is predetermined, and there are limits to the number of cables that can be routed. Therefore, there is a drawback that cables cannot be stretched even if various terminal devices are to be connected to each other. Particularly in places where a large number of cables are concentrated, such as in a computer room, there is a problem in that the cables cannot be laid due to the weight of the cables themselves. Also, when using metal cables, external noise and induced noise from lightning etc. may enter.
This may cause interference with data lines, leading to communication interruptions, and depending on the system, this may cause social problems.

SUMMARY OF THE INVENTION An object of the present invention is to provide a local information transmission system that can transmit different information using the same optical fiber cable by eliminating the above-mentioned drawbacks.

[Means for solving problems]

The local information transmission system of the present invention is a local information transmission system that transmits multiple pieces of information from multiple terminals, in which predetermined information from the terminals is multiplexed and transmitted, the input multiplexed signal is separated, and a predetermined signal is transmitted. An optical fiber cable that is provided with a plurality of terminal signal multiplexing devices for transmitting to the terminals, further equipped with a loop synchronization control device that creates a loop synchronization signal and transmits it to the terminal signal multiplexing device, and has at least two optical fibers built in. The present invention is characterized in that at least one of the loop synchronization control devices and a plurality of the terminal signal multiplexing devices are connected in a loop.

[For production]

The present invention multiplexes a plurality of pieces of information input from a plurality of connected terminals in a terminal signal multiplexing device, and transmits the multiplexed information via an optical fiber cable to a destination terminal signal multiplexing device to which the other party's terminal is connected. The multiplexed signal of information from the other terminal transmitted from the terminal signal multiplexer is separated and transmitted to a predetermined terminal, and the loop synchronization controller separates the multiplexed signal of information transmitted from the multiple terminal signal multiplexers. By establishing loop synchronization, information can be transmitted between predetermined terminals using the same looped optical fiber cable.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a system configuration diagram showing an embodiment of the present invention.

In FIG. 1, a portion surrounded by a dashed line shows an embodiment of the present invention. In the figure, 10 is a loop synchronization control device, and at least one device is required in the same loop. 20 is a terminal signal multiplexing device, and a maximum of 63 devices can be installed in the same loop. 10
0 is an optical fiber cable incorporating at least two optical fibers. The part outside the dashed line indicates a terminal device connected to the device of the present invention, and 200 is a data terminal (
DTE), 300' is a telephone terminal (installation), 400 is a video terminal (TV), and 500 is a facsimile terminal (FAX).
), 600 is a computer (CPU).

FIG. 2 is a block diagram showing details of the loop synchronous control device 1 in FIG. 1. In the figure, 10a is an optical switch, 10b and 10c are electro-optic converters, and 10d.

10e is a photoelectric converter, 10f is a loopback control unit,
10g and 10h are loop synchronization control parts, (N)
is for current use, and (E) is for backup. FIG. 3 is a block diagram showing details of the terminal signal multiplexing device of FIG. 1. In the figure, 20a is an optical switch, 20b and 20c are electro-optical converters, 20d and 20e are photoelectric converters, 20f is a loop bank control section, 20i is a multiplexing section, and 20j is a separation section.

That is, the feature of the present invention is that a loop control device 10 and a plurality of terminal signal multiplexing devices 2 to which a plurality of terminals are connected, respectively.
0 are connected in a loop with the same optical fiber cable 100.

Next, the operation of this embodiment will be explained.

In the terminal signal multiplexing device 20 shown in FIG. 3, signals from terminals such as a data terminal 200, a telephone terminal 300, an image terminal 400, and a facsimile terminal 500 are multiplexed in a multiplexing section 20i, and are looped back. Control unit 20f and electro-optical converter 20b or 20c1 optical switch 20a
The signal is transmitted to a predetermined destination terminal signal multiplexer 20 via an optical fiber cable 100.

The signal arriving at the destination terminal signal multiplexing device 20 passes through the optical switch 20a, the opto-electrical converter 20d or 20e, and the loopback control section 20f, and is separated by the demultiplexing section 20j and transmitted to each terminal.

Note that the setting of the line with the other terminal is performed by specifying the channels dedicated to the multiplexing section 20i and the demultiplexing section 20j, and it becomes possible to perform optical communication between the same channels.

In the loop synchronization control device 10 in FIG. 2, a loop synchronization control section 10g or 10h generates a time-division multiplexed transmission frame for synchronizing signals from each terminal signal multiplexing device 20, and Control unit 10f, electro-optical converters 10b, 10c, optical switch 1
The signal is transmitted to each terminal signal multiplexing device 20 via the optical fiber cable 100 via 0a.

Further, in this system, in order to prevent the system from going down even if the optical fiber cable 100 is broken, the loopback control section 20f performs loopback control to prevent the signal from being cut off due to the cable breakage. Furthermore, it has an optical bypass function to allow the loop to operate normally even if the power is cut off at the terminal station, and prevents system failure by bypassing the light when the power is cut off.

〔Effect of the invention〕

As described above, the present invention provides not only data terminals but also computers, By connecting terminals such as telephone terminals, facsimile terminals, and image terminals and multiplexing their signals all at once, it is possible to reduce the amount of cable wiring, and it is possible to operate at high speeds without being affected by external noise or lightning. This has the effect of providing an in-premises information transmission system that does not receive data.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram showing an embodiment of the present invention. FIG. 2 is a block diagram showing details of the loop synchronous control device shown in FIG. 1. FIG. 3 is a block diagram showing details of the terminal signal multiplexing device shown in FIG. 1. 10... Loop synchronous control device, 10a, 20a...
・Light switch, 10b, 10c, 20b, 20
c...Electro-optical converter, 10d, 10e, 20
d, 20e・-optoelectric converter, 10f, 2Of・
...Loop back control unit, 10g, 10h...Loop synchronization control unit, 20...Terminal signal multiplexing device, 20i
...Multiplexing section, 20j... Separation section, 100... Optical fiber cable, 200... Data terminal (DTP)
, 300...Telephone terminal (installation), 400-...Picture terminal (TV), 500-77 Kushimiri terminal (FA)
X), 600...combination! - data (CPU).

Claims (1)

[Claims] (1) In a local information transmission system that transmits multiple pieces of information from multiple terminals, a terminal that multiplexes and transmits predetermined information from the above terminals, separates the input multiplexed signal, and transmits it to a predetermined terminal. An optical fiber cable is provided with a plurality of signal multiplexing devices, and further includes a loop synchronization control device for creating a loop synchronization signal and transmitting it to the terminal signal multiplexing device. A local information transmission system characterized in that a loop synchronization control device and a plurality of the above terminal signal multiplexing devices are connected in a loop.