JPH0756980B2 - Optical space transmission network - Google Patents

Description

The present invention relates to an optical space transmission network for spatially transmitting control data by an optical signal to control a device.

[Conventional technology]

In the case of transmitting information by optical space transmission, especially 1 to N
In communication, it is difficult to expand the network area due to the spatial line-of-sight restrictions on the transmitting side and the receiving side. Of course, if a repeater is provided, this problem will be solved, but installing a dedicated repeater will increase the cost, and if there are multiple repeaters, it will be difficult to take measures against interference and receive from the transmission circuit. Since a malfunction occurs due to wraparound in the circuit, another problem occurs such as being restricted in the installation place to prevent this or requiring a devised structure.

FIG. 4 shows an optical space transmission device without using a dedicated repeater.
For example, the optical space transmission network disclosed in Japanese Patent Laid-Open No. 59-122143 is provided with a relay function.

In FIG. 4, reference numeral 1 denotes an optical space transmission device having a transmitter T and a receiver R, which is connected to a host computer HC, a network node and the like. Optical space transmission devices 1a-1c
Has a transmitter T, a receiver R, and a data terminal 2 such as a personal computer, as shown in FIG. 5, which receiver R has an optical / electrical converter 3 and a demodulator 4, and T has a modulator 5 and an electro-optical converter 6, and the data terminal 2 has a switch 7 constituting a folding circuit, a control address discriminator 8 thereof, and a memory 9 for storing demodulated data.
have. The optical space transmission device 1d includes a transmitter T and a receiver R.
Consists of.

Upon receiving the optical signal, each of the optical space transmission devices 1a to 1c performs optical / electrical conversion of the optical signal and inputs it to the demodulator 4. The demodulator 4 extracts and demodulates the clock, and the demodulated data is written in the memory 9 by the extracted clock. When sending,
The transmission data obtained by adding the address of the transmission destination and the address of the transmission source to the data to be transmitted enters the modulator 5 through the switch 7, is modulated there, and the modulated output is electro-optically converted, and this is emitted as an optical signal. It The address discriminator 8 checks the transmission destination address included in the output of the demodulator 4, and if the address is not addressed to itself, connects the switch 7 forming the folding circuit to the modulator 5 to output the output of the demodulator 4. To the modulator 5, which is sent out into space through the electro-optical converter 6.

In this configuration, a unique address is assigned to each of the optical space transmission devices 1, 1a to 1c, 1d. When the space optical transmission apparatus 1a transmits to the space optical transmission apparatus 1, it transmits data from the transmitter T with its own address and destination address (in this case, the address of the space optical transmission apparatus 1) attached. The optical space transmission device 1b receives this optical signal, but since the destination is not addressed to itself, the return data is used as it is by the loopback function (without changing the data and the destination address, the source address), and the transmitter T Transfer to the optical space transmission device 1. Since the received signal is addressed to itself in the optical free space transmission apparatus 1,
The loopback mode is released and the received data is sent to the host computer HC.

[Problems to be Solved by the Invention]

Optical space transmission devices 1a ~ 1c in this network, if the destination address is not the address assigned to itself,
Since it has the function of relaying the received signal, the above-mentioned problem has been solved, but the received signal is either received directly from the source or relayed by another optical space transmission device. As shown in FIG. 6, when the optical section transmission device 1 designates the optical space transmission device 1c and sends out an optical signal, it cannot be distinguished whether there is an optical space transmission device which is not the destination.
Repeated relaying may occur between 1a and 1b (representing the number of relaying operations), and the relaying operation may continue.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a practically excellent optical space transmission network that uses a control terminal having a relay function, but does not have a possibility of repeating the relay operation. And

[Means for Solving the Problems]

In order to achieve the above object, the present invention is an optical space transmission network comprising a main controller for transmitting an optical signal and a plurality of control terminals for transmitting and receiving an optical signal, each control terminal being assigned an address. , The main controller sends the control data by designating the address of the destination terminal, and the control terminal decodes the control data and sends the control signal to the controlling device when the received signal is addressed to itself. , If it is addressed to another terminal, the control terminal that performs the relay operation for transmitting the received signal with the relay information and sends the received signal, and the control signal that received the signal having the relay information is not the one addressed to the own terminal The output operation is not performed, and in the second aspect, the relay information is the flag set in the transmission data format as the relay information.

[Action]

In the present invention, when the received signal has relay information and is not addressed to the own terminal, the output operation is not performed, so the relay operation is not repeated.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 10 denotes a main controller, which has a control unit MC and a transmission unit MT, and the transmission unit MT predetermines control data D created by the control unit MC by designating an address of a destination terminal. The transmission circuit has a transmission circuit for transmitting to a modulator (not shown) in a transmission data format, and an electro-optical converter for converting the output of the modulator into an optical signal and radiating it into space. 20A, 20B and 20C are
The control terminal is assigned a unique address, and has a transmitter T, a receiver R, and a controller C, as shown in FIG.

In FIG. 2, the receiving unit R for receiving the optical signal is an optical signal.
An optical / electrical converter 21 for converting Li into an electric signal, and a demodulator for demodulating a received signal converted into an electric signal by the optical / electrical converter 21
22 and sends the demodulated data to the control unit C. Control unit C
Has a received data memory 23 for temporarily storing the demodulated data DD, an address decoder 24 and a controller 25. In response to a command (notification) from the address decoder 24, the transmission unit T reads all the data stored in the reception data memory 23, sets a flag and assembles a transmission data format, and a signal having this transmission data format. Modulator 27 for modulating light and an electro-optical converter
Has 28. In response to a command (notification) from the address decoder 24, the controller 25 reads the control code of the data stored in the reception data memory 23, decodes it, and sends a control signal to the controlling device.

FIG. 3 shows an example of the transmission data format 30.
It comprises a synchronization bit 31, an address bit 32 for designating a transmission destination, a flag bit 33, a control code bit 34 and a check bit.

Next, the operation of this device will be described.

For convenience of explanation, the control unit C of the control terminals 20A, 20B and 20C
It is assumed that the control targets controlled by 1) are the first illuminating lamp, the second illuminating lamp, and the air conditioner, respectively, and the main controller 10 sends a command to operate (ON) the air conditioner.

The control unit MC of the main controller 10 sends a control code 34 for instructing ON of the air conditioning equipment to the transmission circuit by designating the control terminal 20C, and the transmission circuit modulates a signal of a predetermined transmission data format 30. Then, the light is emitted to the room space as an optical signal. At this time, the flag of the transmission data format 30 is not set, and the value of the flag bit is "0".

The optical signal radiated into the space is received by the control terminal 20A, and in the control terminal 20A, the received optical signal is converted into an electric signal by the optical / electrical converter 21, demodulated by the demodulator 22 and then received data is received. The data is stored in the data memory 23. When the received data is stored in the received data memory 23, the address decoder 24 reads the destination address and the flag from the received data stored in the received data memory 23, and determines whether the received data is addressed to its own terminal from the destination address. It is determined whether it is addressed to the terminal, and whether a flag is set (whether it has relay information). If the received data is addressed to its own terminal, it notifies the controller 25 to that effect, but in this case, since it is addressed to the other terminal (20C) and has no relay information, the transmission circuit 26 is addressed to the other terminal. Instruct that data has been received (that relay operation should be performed). Receiving this command, the transmission circuit 26 reads the data (destination address, control code) stored in the reception data memory 23, and modulators this with a flagged (value "1") transmission data format. Send to 27. The transmission signal modulated by the modulator 27 is an electric / optical converter.
At 28, it is converted into an optical signal L ₀ and emitted into space. This optical signal is received by the control terminals 20B and 20C. Control terminal 20C
Then, the address decoder 24 determines that the received data is addressed to its own terminal.
The control code of the received data stored in 23 is read, the code is decoded, and the ON command is given to the air conditioning equipment. In the control terminal 20B, since the destination address is not addressed to itself and the flag is set, the data is relayed, so that the address retarder 24 is provided in both the controller 27 and the transmission circuit 26. The command is not issued and the contents of the reception data memory 23 are erased.

As described above, in this embodiment, the control terminals 20A to 20C determine that the own terminal is the non-relay stage when the received signal is flagged, and when the received signal is not addressed to the own terminal. Since the received data is discarded, the repeating operation of the relay described above does not occur.

〔The invention's effect〕

As described above, according to the present invention, each control terminal adds relay information at the time of relaying a signal and transmits the signal, and does not perform an output operation when the received signal has this relay information and is not addressed to the own terminal. As a result, the relay operation is not repeated, and since the control terminal itself has a relay function, there is no malfunction due to the sneak of the above-mentioned optical signal, so there are few restrictions due to price or space perspective, In addition, it becomes possible to easily construct a practically excellent optical space transmission network.

[Brief description of drawings]

FIG. 1 is a network showing an embodiment of the present invention, FIG. 2 is a block diagram showing a concrete configuration of a control terminal in the above embodiment, FIG. 3 is a transmission data format in the above embodiment, and FIG. FIG. 5 is a diagram showing an optical space transmission network, FIG. 5 is a block diagram showing an internal configuration of an optical transmission device in the above-mentioned conventional example, and FIG. 6 is a network diagram for explaining problems of the above-mentioned conventional example. 10 ... Main controller, 20A to 20C ... Control terminal, 21 ... Optical / electrical converter, 22 ... Demodulator, 23 ... Received data memory, 24 ...
… Address decoder, 25 …… Controller, 26 …… Transmission circuit,
27 ... Modulator, 28 ... Electro-optical converter, R ... Receiver, M
T, T ... Transmitter, MC, C ... Control.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical indication H04B 10/22

Claims (2)

[Claims] 1. An optical space transmission network comprising: a main controller for transmitting an optical signal; and a plurality of control terminals for transmitting and receiving an optical signal, each control terminal being assigned an address.
The main controller sends the control data by designating the address of the destination terminal, and the control terminal decodes the control data and sends the control signal to the controlling device when the received signal is addressed to itself. If it is addressed to another terminal,
An optical space transmission network characterized by performing a relay operation of carrying and transmitting relay information, and among control terminals having received a signal having the relay information, a control terminal whose received signal is not addressed to itself does not perform an output operation. 2. The optical space transmission network according to claim 1, wherein the relay information is a flag set in a transmission data format.