JPH0756981B2 - Optical space transmission network - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a multistage 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. 5 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. 5, reference numeral 1 is 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. 6, and the 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. Since it is not possible to distinguish whether or not there is an optical space transmission device 1a that is not the destination when the optical section transmission device 1 specifies the optical space transmission device 1c and sends out the optical signal L, as shown in FIG. Repeated relays occur between 1b (,, ...
• indicates the number of relay operations), and relay operations may continue.

The present invention has been made to solve the above problems, and provides a practically excellent multi-stage optical space transmission network that uses a control terminal having a relay function, but is free from the risk of repeated relay operations. With the goal.

[Means for Solving the Problems]

In order to achieve the above object, the present invention provides a multistage optical space transmission network that includes a main controller that sends an optical signal and a plurality of control terminals that send and receive an optical signal, and each control terminal is assigned an address. The main controller sends the control data by designating the address of the destination terminal and the number of signal relay stages, and the control terminal decodes the control data when the received signal is addressed to itself and the controlling device When a dead time is set in consideration of the number of signal relay stages while sending a control signal to the other terminal, and if it is addressed to another terminal, a relay operation is performed to update the number of signal relay stages and send the received signal, Among control terminals that have received a signal whose number of signal relay stages is a predetermined value, those whose received signal is not addressed to itself are configured not to perform an output operation. In claim 2, the number of signal relay stages is updated. - And that, the predetermined value was such that 0 stages.

[Action]

In the present invention, until the value of the number of signal relay stages up to the destination terminal included in the received signal is updated to a predetermined value, the control terminals of each stage are sequentially relayed, the number of signal relay stages is a predetermined value, and The control terminal that receives the signal addressed to it performs control operation. Although the number of signal relay stages is a predetermined value, the control terminal that has received the signal addressed to the other terminal does not perform the relay operation or the control operation.

〔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 has a control unit MC that transmits the destination terminal address and the number N of signal relay stages to the destination terminal. code)
And a transmission circuit that sends the control data created by designating the specified transmission data format 30 to a modulator (not shown),
It has an electro-optical converter that converts the output of the modulator into an optical signal Li and emits it to the space, and stops transmitting the signal during a predetermined control waiting time T3 after the signal is transmitted. 20A, 20B, 20
C and 20D are control terminals arranged in multiple stages, each of which is assigned a unique address. Control terminals 20A-2
As shown in FIG. 2, 0D has a transmitter T, a receiver R, and a controller C.

In FIG. 2, a receiving unit R for receiving an optical signal includes an optical / electrical converter 21 for converting the optical signal into an electric signal, and the optical / electrical converter.
Demodulator 22 for demodulating the received signal converted into an electric signal by 21
And sends the demodulated data to the control unit C. Control unit C
Has a reception data memory 23 for temporarily storing the demodulated data, an address decoder 24, and a controller 25. The transmission unit T has a transmission circuit 26, a modulator 27, and an electro-optical converter 28. The transmission circuit 26 is activated by a command from the address decoder 24 and reads all the stored data from the reception data memory 23. , The stage number code N is updated (-1 subtraction count) to assemble the transmission data format 30. The modulator 27 modulates the signal having the transmission data format 30 and inputs it to the electro-optical converter 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.

If the address decoder 24 determines that the received data is addressed to its own terminal, the control terminals 20A to 20D, after receiving,
Set dead zone at time T2. This dead zone T2 is the main controller
10. If the control terminals 20A to 20D set the time required for signal transmission and reception to T1 and the processing time delay to TL, T2N × (T1 + TL) (1) where N is the value of the number of signal relay stages received Given. The control waiting time T3 is given by T3N.times. (T1 + T2) + TL ... (2).

FIG. 3 shows an example of the transmission data format 30.
It comprises a synchronization bit 31, an address bit 32 for designating a destination, a network stage number code bit 33, a control code bit 34 and a check bit 35.

Next, the operation of this device will be described with reference to the signal time chart of FIG.

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

The control unit MC of the main controller 10 sends a control code for instructing lighting (ON) of the third illumination lamp to the transmission circuit by designating the control terminal 20C (address and stage number code), and the transmission circuit Modulates a signal of a predetermined transmission data format 30 and emits it as an optical signal Li into the room space. The stage number code of the transmission data format 30 at this time is “2” because the number of signal relay stages up to the control terminal 20C is 2.

The optical signal Li radiated to the room space is the control terminal 20A.
In the control terminal 20A, the received optical signal Li is converted into an electric signal by the optical / electrical converter 21, demodulated by the demodulator 22 and stored in the reception 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 stage number code 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 another terminal, and whether the stage number code is a predetermined value "0" which means a non-relay stage. If the received data is addressed to its own terminal, it notifies the controller 25 to that effect. In this case, since the stage number code is "2", the transmission circuit 26 is informed that the received data should be relayed. Order. Receiving this command, the transmission circuit 26 reads the data (destination address, control code) stored in the reception data memory 23 and sends it to the modulator 27 in the transmission data format with the stage number code updated to "1". The transmission signal modulated by the modulator 27 is converted into an optical signal L ₀ by the electro-optical converter 28 and radiated into space. This optical signal L ₀ is received by the control terminal 20B at the next stage. In the control terminal 20B, since the stage number code of the received data is "1", the transmission circuit 26 is instructed to perform the relay operation. Receiving this command, the transmission circuit 26 reads the data (destination address, control code) stored in the reception data memory 23 and modulates it in the transmission data format in which the stage number code is changed to "0", as in the above. To the container 27. The transmission signal modulated by the modulator 27 is converted into an optical signal L ₀ by the electro-optical converter 28 and radiated into space. This optical signal L ₀
Is received by the control terminals 20C and 20D at the next stage.

In the control terminal 20C, the address decoder 24 determines from the stage number code “0” that the own terminal is the non-relay stage and the received data is addressed to the own terminal. Therefore, the controller 27 is stored in the received data memory 23. The control code in the received data is read and decoded to give an ON command to the third illuminating lamp and set a dead zone at time T2. This time T2
Is T20 × (T1 + TL) 0 as shown in FIG.

In this case, the control terminal 20C receives the signal from the control terminal 20B, but also receives a signal from the main controller 10 and the control terminal 20A to control the third illuminating lamp that is the control target (ON command).
However, the dead zone T2 is T22 × (T1 + TL) when it is received from the main controller 10, and T22 × (T2 × (T1 + TL) when it is received from the control terminal 20A. Therefore, the control signal (ON command) is not repeatedly transmitted.

As described above, the control terminal 20D also receives from the control terminal 20B at the same time as the control terminal 20C, but since the destination address is not addressed to itself and the stage number code is "0" which means a non-relay stage. The address decoder 24 does not issue a command to either the controller 27 or the transmission circuit 26, and erases the contents of the reception data memory 23.

As described above, in the present embodiment, the main controller 10 sends the control data by designating the relay stage number N to the destination terminal and the address, and the control terminals 20A to 20D have the stage number code of the received signal of "0". If not, relay operation is performed, and it is “0”,
If the address is not its own address, the relay operation is not performed, so that the repeat relay described above is surely prevented.

When the received signal is addressed to itself, each of the control terminals 20A to 20D sets the dead zone T2 after reception and interrupts the reception operation, so that it operates only with the signal that arrives first and controls the control target. There is no danger of malfunction.

〔The invention's effect〕

According to the present invention, as described above, the main controller specifies the number of relay stages up to the destination terminal and transmits a signal, and each control terminal updates the number of signal relay stages up to the destination terminal and transmits the signal when relaying the signal. However, when the value of the number of signal relay stages of the received signal is updated to a predetermined value and it is not addressed to the own terminal, the output operation is not performed, so that the relay operation is not repeated and the control terminal Since it has a repeater function itself, there is no malfunction due to the above-mentioned wraparound of optical signals, so there are few restrictions due to price and space perspective, and an optical space transmission network that is practically excellent can be easily reached. It is possible to build without worrying about the route,
There is an advantage that the number of control terminals can be easily increased or decreased.

[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. A signal time chart for explaining relay operation according to an example, FIG. 5 is a diagram showing a conventional optical space transmission network, FIG. 6 is a block diagram showing an internal configuration of an optical transmission device in the above-mentioned conventional example, and FIG. The figure is a network diagram for explaining the problems of the conventional example. 10 ... Main controller, 20A to 20D ... 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. A multi-stage optical space transmission network comprising a main controller for transmitting an optical signal and a plurality of control terminals for transmitting and receiving the optical signal, wherein each control terminal is assigned an address. The controller sends the control data by designating the address of the destination terminal and the number of signal relay stages to the destination terminal, and the control terminal decodes the control data and controls it when the received signal is addressed to itself. Set the dead time considering the number of signal relay stages while sending the control signal to the equipment,
When it is addressed to another terminal, the relay operation of transmitting the received signal after updating the number of signal relay stages is performed, and among the control terminals that have received the signal in which the number of signal relay stages of the received signal is updated to a predetermined value. An optical space transmission network characterized in that an output operation is not performed if a received signal is not addressed to its own terminal. 2. The optical space transmission network according to claim 1, wherein the number of signal relay stages is updated by decrementing the number of stages by 1, and the predetermined value is 0.