JPS6021644A - Data transmission system - Google Patents

Abstract

PURPOSE:To attain the simplicity and uniformity of the relay/changeover and priority transmission control of data and the managing function by switching a level of an optical signal transmitted from an optical transceiver of an optical data transmission system and identifying a received signal. CONSTITUTION:The optical transceivers 20-22, 24 are constituted so that a level of the optical signal transmitted from them is switched and the fact which of level is the level of the received optical signal is identified. The optical transceivers 20-22, 24 are coupled to a photocoupler by optical fiber cables 26-29 so that the optical transmission signal from the optical transceivers 20-22, 24 is received by an device other than the transceivers 20-22, 24. The signal level is identified by a reception level detecting function provided to all the optical transceivers 20-22, 24 to supervise the type of transmission destination or communication state of other stations thereby attaining priority control.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a data transmission system that transmits digital data by light between a plurality of terminal devices and data processing devices.

FIG. 1 is a block diagram showing an example of a conventional data transmission system of this type.
.

(31 is a terminal device, (+51, +61 is a terminal control device, (7) l″j: transmission control device on the terminal side, 18
+ , +91 , 1101 , (111 is an optical transmitting and receiving device, (2) is a transmission control device on the center side, (131 is a data processing device, α→ is a storage device, and αυ and αO are optical fiber cables.

1lljl where a plurality of terminal devices fil, +21, +31 exist is called the terminal side, and the data processing device (13
, the side where the storage device α→ exists is called the center side.

Data is transmitted between the terminal side and the center side in response to requests from the terminal devices il+, 12+, +31.

The data on the terminal side is controlled by the terminal switching function, transmission control function, switching or multiplexing function of the transmission control device 17), and passes through the optical transmitting and receiving device (81, former fiber cable hinoki, optical transmitting and receiving device (9)) and then transmitted to the center side.

On the center side, the transmission control device αa1 data processing device a4 receives data from the terminal side, identifies the content,
Format conversion, processing, processing, etc. are performed, and the registered data is stored in the storage device α◆ as necessary.

Data transmission from the center side to the terminal side is performed by accessing the storage device α4 according to the program and schedule in the data processing device (3), performing data input/output format conversion, manual processing, processing, etc., and then transmitting control. Device (2)
, the optical transmitter/receiver device (optional), the optical fiber cable 0Q, and the optical transmitter/receiver device note.

In the transmission control device 17), connection control to the corresponding terminal device, data format conversion, transfer, synchronization, etc. are performed in accordance with address designation or commands from the center side.

Since the conventional data transmission system of God is configured as described above, functions such as bidirectional connection control, order ff1ll, data format conversion, synchronization, and monitoring are required for data transmission and reception, and logic circuits and fli! I Ml
1. QNMN small end transmission control device (7) as the program becomes sloppy, reducing device reliability and increasing costs.
Transfer side and terminal control device +41, +51
, 161 sides are different, the conversion function and management function are complicated, and it has been necessary to provide a direct data transmission function between the terminal devices.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and it switches the level of the optical signal transmitted in each optical transmitter/receiver and determines which level the received optical signal is. Each original transmitting/receiving device 6 is configured so that the optical signal transmitted from each optical transmitting/receiving device can be received (W) in any device other than the optical transmitting/receiving device that sent this optical signal. A data transmission system that is connected to an optical coupler using an original fiber cable, simplifies data relaying, switching, priority transmission control, and 1. simplifies the physical functions, homogenizes the interface, and also has data transmission functions between terminal devices. is intended to provide.

An embodiment of the present invention will be described below.

FIG. 2 is a block diagram showing one embodiment of the present invention.
The figure shows Oitefi+, +21, +31, 031
, indicates parts corresponding to the same reference numerals in the QJU & 4.1 diagram, C71.

tlEil, C1!111-J: Terminal side transmission III
ml device, (2o), (21J, (22)
B optical transmitter/receiver, (23) & optical coupler, (24) optical transmitter/receiver, (25) center side transmission control device, (2
6) l (27).

(28) and (29) are optical fiber cables.

Data to be transmitted from the center side to the terminal side is searched through the storage device α◆◆◆υ according to the program of the data processing device (13), format-converted in the transmission control device (25J), and an address is added. ) is transmitted to the optical coupler (23).The optical transmitter/receiver (
The transmitted optical signal of 24) is equally distributed to the optical fiber cables (27), (28J, (29)) in the optical coupler (23), and the optical transmitter/receiver (zo), (2υ,
(22) is received, converted into an electrical signal, converted into a format, and connected to a transmission control device (17)
, (18), (Transferred to 19J. In transmission control device (17) , received by the corresponding terminal device (h'
l, / Transfer data money. From the center side, the state continues until the emergency signal 1) [extincts].

Connoisseur? Based on the common address specification from the IS1 center side, data broadcasting and daily communication are performed.

Next, the case where data is transmitted from the terminal side to the center side or between terminals will be explained.

Transmission data VJ1 transmission control device 07) from terminal devices 111, 121, 131), (ts), (19
), the destination address is converted into several IJ formats, and then the optical transmitter/receiver (20), (,2υ.

(22) Transmitted to optical coupler (23) via 't') 25
be done. In this case, the optical transmitter/receiver that sent out the source signal earliest gets the right to transmit, and the optical coupler (23) distributes the transmitted signal evenly to the optical fiber cables connected to other optical receivers. and optical transmitter/receiver 1 on the center side.
(24) Received by other optical transmitting/receiving devices on the terminal side. The destination address is identified by the transmission control device f (25) and the transmission control device corresponding to the above-mentioned other optical transmitting/receiving devices on the terminal side, and the subsequent data is received by the terminal or center where the destination is specified. When transmitting an optical signal from an optical transmitter/receiver, the level of the transmitted optical signal is switched depending on whether it is received by the center side or the Q::A terminal side. For example, it is switched to low level when receiving from the center side, and to low level when receiving from the terminal side.

al) Figure 3 is an explanatory diagram showing an example of optical signals of different levels.

In the figure, (30) indicates the level and timing of the transmitted optical signal when the original signal is transmitted and received between the optical transmitting and receiving devices on the terminal side and the center side. When the transmission control device detects that data transmission to the center side is interrupted, the output of the optical transmitter/receiver is (
30) is in state 11, and the high level signal remains for a while (
Header information (32) consisting of a synchronization signal, destination address, and local address is sent out, followed by data information (33). When the sending of these series of information blocks () (called kerato) is finished,
The output V'1 (30) returns to the previous state i). The optical transmitter/receiver (24) on the center side is set to always send out a high level signal.

(34) indicates the level and timing of the transmitted optical signal when transmitting and receiving optical signals between the optical transmitting and receiving devices on the terminal side.When the transmission control ill device detects a demand for data transmission to the terminal device, , the output t of the optical transmitting/receiving device becomes the state l( of (34)), and the header information (36) consisting of the destination address and the own address is sent out, which is lower than the H of (30), and then the data information ( 37) is sent out. When the sending of the packet is completed, the output returns to the L state of (34).

All optical transceivers (20), (2υ, (22), (
24) The reception level detection function at V(m) identifies the signal level, monitors the type of transmission destination or the communication status of other stations, and performs priority control.

FIG. 4 is a block diagram showing an example of an optical transmitter/receiver (M device) according to the present invention.
0) is the driver, (4υ is the light emitting element, (42) is the control signal line for switching the output level of the light emitting element (4υ), (43) 1'' is the output signal line to the original coupler or the original 7 Aipa cable, (44) is a human power signal line or optical fiber cable from the original coupler, (45 light receiving elements, (46)
is the receiver, (47) is the gogoki, (48) is the receiver (
46) is a signal line for detecting the input level, and (49) is an output and clock signal line.

This optical transmitter/receiver and the transmission 1 open side j device connected thereto can control switching of the output level of the driver and identify the input level of the receiver.

In addition, in the second embodiment, a case where a master-slave relationship exists between the center side and the terminal side is shown, but even when the center side does not exist and the processors and terminal devices are all configured equally,
The same can be said. It's a trench, the 1 hour report transmitted is an image,
Any type of media is acceptable, such as audio.

In the above embodiment, an example was shown in which the level of the transmitting optical signal is switched between two levels, but is it possible to switch the level of the transmitting optical signal between two levels? l1jj1
It is also possible to switch to the H-number level as necessary for priority control or the like.

As described above, according to the present invention, data moderation, switching, and priority transmission 1ii11佃1,管1! l! Functionality is simplified, the transmission ink face is homogenized, and reliability is improved.
1t, cost reduction can be realized. 1, U"C: Interrupt control, priority 1 by switching the signal level
This has the effect that efficient data transmission can be achieved by performing all operations on the 1i11 side.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an example of a conventional data transmission system of this type, Fig. 2 is a block diagram showing an embodiment of the present invention, and Fig. 3 is an explanatory diagram showing an example of optical signals of different g levels. , FIG. 4 is a block diagram showing an example of an optical transmitter/receiver according to the present invention. In the figure, (11, 121, +31 are terminal devices, (13
) is a data processing device, α→ is a storage device, (17J,
(18), (19), (25) are transmission control devices, (
20), (21H (22), (24) is a device for optical transmission and reception, (23) is an optical coupler, (26H (27), (28)
Eight (29) crawling T-fiber cables, (39) encoder, (40) driver, (41) light emitting element, (45)
(4) is the receiver, and (47) is the decoder. The same reference numerals in each figure indicate the same or corresponding parts. Agent Masu Oiwa NolIij

Claims (1)

[Claims] In a data transmission system that transmits digital data by light between multiple terminal devices and data processing devices, the multiple terminal devices and data processing devices are each connected via a transmission control device, and the level of the optical signal to be sent is controlled. An optical transmitter/receiver that can switch to any one of a plurality of levels and can identify which of the plurality of levels the level of a received optical signal is, and an optical signal transmitted by these optical transmitter/receivers. 1. A data transmission system comprising an optical coupler coupled to each of the optical transmitting/receiving devices via an optical fiber cable so that the data can be received by any of the optical transmitting/receiving devices other than the optical transmitting/receiving device.