JPS60153239A - Data communication system - Google Patents

Abstract

PURPOSE:To reduce the number of connections of optical fibers and to move and increase easily terminals by distributing optical repeaters mutually connected by optical fibers around an optical distributor in each room, and executing optical space communication between the optical repeaters and plural terminals. CONSTITUTION:Optical repeaters 11, 12 each of which consists of an optical fiber transmitter, optical fiber receiver, optical space transmitter, and an optical space receiver are provided in respective rooms, signals transmitted from the optical fiber transmitters of respective repeaters 11, 12 through optical fibers 1a, 1b are distributed by optical fibers 1e, 1f by a star coupler 2 and inputted to the optical fiber receivers of the repeaters 11, 12. The outputs of the optical fiber receivers of respective repeaters 11, 12 are transmitted to plural optical space transmitters/receivers 13-16 through respective optical space transmitters and converted into electric signals and the electric signals are inputted to respective terminal equipments 7-10. Signals from respective terminal equipments 7-10 are converted into optical signals by the optical transmitters/receivers 13-16 and received by the optical space receivers of the optical repeaters 11, 12 through the optical space transmitters, and the received signals are transmitted to the optical fiber transmitters of the optical repeaters.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a data communication system, and particularly to an improved data communication system for performing data communication between devices such as computers and various control devices installed indoors.

[Prior art]

FIG. 1 is a block diagram showing a data communication system according to the prior art. In the figure, /a to /h are optical fibers,
1 is an optical distribution means such as a star coupler, 3 to 6 are optical transceivers, each consisting of an optical transmitter 3a to 6a and an optical receiver 3b to 6b, and 1 to 10 are computer terminal devices. .

In the data communication method W described above, for example, the terminal device 7
After the electrical data sent from the optical fiber /a is converted into an optical signal by the optical transmitter 3a in the optical transceiver 3,
He is led to Star Cup Rako through the process. This star coupler λ equally distributes the optical signal received from the optical fiber 77 to the optical fibers le to fh. The distributed optical signals are sent to optical receivers 3b to 6b in optical transceivers 3 to 6, respectively. Each party receiver 3a to 6b converts the received optical signal into an electrical signal and outputs the received data to each terminal device 7 to 10. In this way, data communication is performed between each terminal device.

In the data communication system using the conventional technology as described above, a lot of optical fiber wiring work is required, and
Since the number of terminal devices that can exchange data with each other is limited to the number of branches of the star coupler, it is difficult to expand the number of terminal devices, and furthermore, it is difficult to move the terminal devices themselves.

[Summary of the invention]

In order to improve the drawbacks of the data communication system according to the prior art described above, this invention installs only seven optical repeaters in a room, and uses infrared rays to transmit data between the optical repeaters and each terminal device. The purpose of the present invention is to provide a data communication method for performing communication.

[Embodiments of the invention]

FIG. 2 is a block diagram showing an embodiment of the data communication system according to the present invention. In the figure, // and /2 are optical repeaters, and /3 to /6 are optical transceivers.

FIG. 3 is a detailed block diagram of, for example, the optical repeater /l shown in FIG. 76 is an optical fiber transmitter, //b is an optical fiber receiver, //C is a modulation circuit, //d is a drive circuit, //e is an optical space transmitter such as a light emitting element, //f is an optical space receiver For example, a light receiving circuit, //fj is a filter, /lh is an amplifier,
And //L is a demodulation circuit.

FIG. 4 is a detailed block diagram of, for example, the optical transceiver /3 shown in FIG. 2. Since the optical transceivers /4' to /6 have the same configuration, only the optical transceiver /3 will be explained in detail. do. In the figure, /3a is a light receiving circuit, /,? b is a filter, /, 7c is an amplifier, /, ? d is a demodulation circuit, /
Je is a modulation circuit, /3f is a drive circuit, 13g is a light emitting element, and /,,? h is an interface circuit.

In the data communication system of the present invention configured as described above, for example, data sent from a terminal device is modulated by a modulation circuit /3e via an interface circuit /3h of an optical transceiver /3, Drive circuit/? The light is amplified by f, and the light emitting element 13P converts it into an optical signal, which is then radiated into space. This radiated optical signal is received by the optical space receiver //f of the optical repeater //, is demodulated by the demodulation circuit /IL via the filter //l and the amplifier //h, and is sent to the optical fiber transmission FA / / A to the optical fiber /a? is sent as the number. This optical signal is guided to a star coupler λ, where it is equally distributed to each optical fiber /e and /f. The distributed optical signals are transmitted to the first optical repeaters l/ and l, ! guided by.

The optical signal sent to the optical repeater // via the optical fiber ρ is converted into an electrical signal by the optical fiber receiver //b and sent to the modulation circuit l/C. The electric signal changed here is amplified by the drive circuit//d, and then optical spatial transmission 8
//e converts it into an optical signal and radiates it into space. The emitted optical signal is received by the optical transceiver 13 and/or. For example, an optical signal received by the optical transceiver 13 is converted into an electrical signal by the light receiving circuit 13 &. This electrical signal is demodulated by a demodulation circuit /3e via a filter /3'r) and an amplifier /3C, and sent to the terminal device 7 via an interface circuit /, 7h. To summarize the above, for example, when performing data communication from the terminal device 7 to the terminal device /θ, the terminal device 7-optical transceiver/3-optical repeater//-
Optical fiber/11-star coupler 2-optical fiber/f
Data communication is performed through a transmission path between - source repeater/2 - optical transceiver 16 and terminal device io.

Note that in the above embodiment, a star coupler is used, but instead, an optical receiver is used to convert an optical signal into an electrical signal, and this electrical signal is converted back into an optical signal by an optical transmitter. It is also possible to adopt a method in which the

〔Effect of the invention〕

As mentioned above, according to the data communication method of the present invention,
Optical repeaters connected to each other by optical fibers centered around a star coupler are installed in each room, and multiple terminal devices in each room communicate optically with the optical repeater via optical transceivers. This configuration has the advantage of requiring fewer optical fiber connections and making it easier to move and add terminal devices.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a data communication method according to the prior art, FIG. 2 is a block diagram showing an embodiment of the data communication method according to the present invention, and FIG. 3 shows the optical repeater configuration shown in FIG. 1. Detailed Block Diagram FIG. 9 is a detailed block diagram showing the seven-channel configuration of the optical transceiver shown in FIG. 2. Fig.
l/~/Y/e optical repeater, 73~/6... optical transceiver,
//a・Optical fiber transmitter, //b Ya・Optical fiber receiver 4'Q +6h, //C and /3e・L modulation circuit, //
d and /lff-” drive circuit, //e...optical space transmitter,
//f・・Optical space receiver, //f and /Jb@-filter, /lh and/, 3c”・amplifier, //L and/, ?d・・
Demodulation circuit, /Ja...light receiving circuit, /3f...light emitting element,
//h...Interface circuit. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Flame 1 symbol 2 symbols Flame 3 symbol light 4 symbol

Claims (3)

[Claims] (1) Seven units are installed in each room, each having an optical fiber transmitter, an optical fiber receiver, an optical space transmitter, and an optical space receiver, and the output of the optical space receiver is transmitted to each of the optical fiber repeaters. an optical distribution means connected between the optical fiber transmitter and the 16 optical fiber receivers, for distributing the output of one optical fiber transmitter to all the optical fiber receivers; and optical space communication with each of the two relays. A data communication system that includes multiple optical transceivers that perform multiple optical transceivers, and terminal devices that are individually electrically connected to each optical transceiver. (2) The data communication system according to claim 1, wherein the optical distribution means is a star coupler. (3) The data communication system according to claim 1, wherein the optical distribution means comprises an optical receiver and an optical transmitter.