JP4402251B2 - Optical space transmission equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical space transmission apparatus that transmits information to a remote place by optical radio.
[0002]
[Prior art]
An optical space transmission device modulates a transmission signal into an optical signal on the transmission side, transmits this optical signal in the atmospheric space toward the reception side, and demodulates the optical signal from the transmission side on the reception side. This is an apparatus for transmitting information signals through the atmospheric space.
[0003]
However, the light beam in the optical space transmission device is affected by the attenuation of rain, fog, etc. in the air that is the transmission path, and transmission becomes uneasy, so the optical communication device can communicate normally. As a guide for determining whether or not there is a device that displays only the direct current component level of light necessary to determine whether or not light transmitted from the opposite device is received, is widely known.
[0004]
[Problems to be solved by the invention]
However, the light beam in the above-described optical space transmission device is affected by attenuation due to the influence of rain, fog, etc. in the air that is the transmission path, and transmission abnormalities cause communication abnormalities. In fact, even if there is no abnormality in the optical space communication, it is often questioned that an abnormality has occurred in the optical space communication. Furthermore, it is necessary to call a service man each time an abnormality occurs to check whether an abnormality has occurred in optical wireless communication.
[0005]
In addition, since the optical space transmission apparatus described above displays only the direct current component level of light, it is not possible to determine the location of the abnormality by itself, and if a communication abnormality occurs, is the optical space communication normal? In order to confirm whether or not, it is necessary to temporarily stop communication, connect an error rate measuring device or the like to the optical space communication device, and confirm whether or not an error has occurred.
[0006]
However, optical space transmission devices are often installed at two remote locations, and when detecting an abnormal location as described above, both service personnel must communicate and detect the abnormal location. In addition, a large amount of time and special equipment are required to detect an abnormal part, such as using special equipment such as an error rate measuring device. However, this method requires two or more service personnel and special equipment such as an error rate measuring device for each occurrence of an abnormality, and therefore requires a great load for handling the service.
[0007]
In addition, this type of optical space transmission device is often used for 24 hours, and prompt recovery is required. However, in the above-described method, it takes time to detect an abnormal part, so that recovery is delayed and the operation rate of optical wireless communication is delayed. Is the cause of dropping.
[0008]
Also, because there is no way to know what caused the communication error at this time, if the serviceman rushes to resolve the abnormal condition, the communication will return to normal and an abnormal phenomenon will occur. It becomes very difficult to verify later, and the situation is observed until the next occurrence of abnormality, which causes anxiety to the user. Furthermore, since the state of the optical space communication apparatus can be grasped only after going to the site, a countermeasure must be considered from that point, which also causes a delay in the response.
[0009]
The object of the present invention is to solve the above-mentioned problems, and when an abnormality occurs in optical space communication, the location of the abnormality can be detected at a glance in the receiving unit, and a communication abnormality occurs after the communication abnormality occurs. It is an object of the present invention to provide an optical space transmission device that makes it easy to investigate the cause of the problem and further knows the status of the communication abnormality from a remote location and can investigate the cause of the communication abnormality without going to the site from the information.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, an optical space transmission device according to the present invention is an optical space transmission device that transmits and receives information using an optical wireless device with an opposite device arranged to face each other at a predetermined distance. The optical signal generated by combining the main signal and auxiliary signal From the opposite device Receive A converter for converting into an electric signal, and the electric signal; The auxiliary signal component of the optical signal is extracted from the optical signal by an auxiliary signal extraction filter, and the auxiliary signal component is extracted. DC component level detection means for detecting the DC component level of Said DC component level determination means for determining whether or not the DC component level of the current optical signal is normal from the DC component level, and the electrical signal A main signal component of the optical signal is extracted from the main signal component by a main signal extracting filter, AC component level detection means for detecting the amplitude level of Said AC component level determining means for determining whether the amplitude level of the current main signal component is normal from the amplitude level, clock component extracting means for extracting a clock component from the electrical signal, and the clock component extracting means Synchronization determining means for determining whether or not a clock component has been extracted; and a direct current component level determining means, the alternating current component level determining means, and display means for displaying determination information by the synchronous determining means. It is characterized by.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail based on the embodiments shown in the drawings.
FIG. 1 is a configuration diagram of an optical space transmission apparatus according to the present embodiment, and includes a transmission apparatus 1 and a reception apparatus 2. The transmission device 1 is provided with a main signal input unit 3 for transmitting a main signal to the opposite device and an auxiliary signal generation unit 4 for generating an auxiliary signal for detecting the optical DC component level in the opposite device. Has been. The multiplexing unit 5 is connected to an electrical / optical conversion unit 6 that converts electrical signals into optical signals. The electrical / optical conversion unit 6 includes a laser drive circuit 7 and a laser diode 8, and lenses 9, 10, and 11 are arranged in the emission direction of the laser diode 8.
[0015]
A receiving device 2 is provided in the traveling direction of the lens 11, and lenses 12, 13, and 14, and an optical / electric converting unit 15 that converts received light into an electrical signal are arranged in the incident direction of a light beam from the lens 11. ing. The optical / electrical converter 15 includes a light receiving element 16 and a light receiving circuit 17. Light reception The output of the circuit 17 is connected to the amplifier 18. The output of the amplifying unit 18 is connected to an auxiliary signal extracting filter 19, a main signal extracting filter 20, a clock extracting unit 21, and a waveform shaping unit 22.
[0016]
The output of the auxiliary signal extraction filter 19 is connected to the auxiliary signal detection unit 23, and the output of the main signal extraction filter 20 is connected to the main signal detection unit 24. The outputs of the auxiliary signal detector 23, the main signal detector 24, and the clock extractor 21 are connected to the CPU 25, and the output of the CPU 25 is connected to the display unit 26. The output of the clock extraction unit 21 is connected to the waveform shaping unit 22, and the output of the waveform shaping unit 22 is further connected to the signal output unit 27.
[0017]
The main signal input to the main signal input unit 3 in the transmitter 1 is combined with the auxiliary signal generated from the auxiliary signal generation unit 4 in the multiplexing unit 5, and then the laser drive circuit in the electrical / optical conversion unit 6. 7 Is converted into an optical signal via the laser diode 8, and the optical signal output from the laser diode 8 is output to the opposing receiving device 2 via the lenses 9, 10, 11. Further, the light is input to the light receiving element 16 in the optical / electrical conversion unit 15 through the lenses 12, 13, and 14 of the receiving device 2, is converted into an electric signal in the light receiving circuit 17, and is output to the amplification unit 18.
[0018]
The electrical signal amplified by the amplifying unit 18 is extracted with an auxiliary signal component by an auxiliary signal extracting filter 19 and output to the auxiliary signal detecting unit 23. The auxiliary signal detector 23 converts the amplitude level of the input auxiliary signal component into a voltage and outputs it to the CPU 25. Further, since the auxiliary signal level generated by the auxiliary signal generator 4 is kept constant, when the DC component level of the received optical signal increases or decreases, the auxiliary signal level also increases or decreases in proportion to the increase or decrease. Therefore, by measuring the increase / decrease in the auxiliary signal level, it is possible to know the increase / decrease in the DC component level of the received optical signal.
[0019]
The main signal component of the electric signal amplified by the amplifying unit 18 is extracted by the main signal extracting filter 20 and output to the main signal detecting unit 24. The main signal detector 24 converts the amplitude level of the input main signal into a voltage and outputs it to the CPU 25. Since the AC component in the optical signal is the signal component of the data to be transmitted, the AC component of the received optical signal is equivalent to the main signal that is the data signal to be transmitted.
[0020]
Further, the electric signal amplified by the amplifying unit 18 is output to the clock extracting unit 21. The clock extracting unit 21 extracts a clock, converts information indicating whether synchronization has been achieved, into a voltage, and outputs the voltage to the CPU 25.
[0021]
The CPU 25 extracts the DC component level, the AC component level, the clock component from the data signal, analyzes the information on whether or not the synchronization is achieved, and each state, or information on the location where the abnormality has occurred obtained from each state, or both Is displayed on the display unit 26.
[0022]
The electric signal amplified by the amplifying unit 18 and the clock signal extracted by the clock extracting unit 21 are output to the waveform shaping unit 22, and the waveform shaping unit 22 regenerates the data signal based on these signals and generates a signal output unit 27. Output to.
[0023]
FIG. 2 shows a configuration diagram of the clock extraction unit 21, and the clock extraction unit 21 includes a phase comparator 31, a VCO (voltage control circuit) 32, and a loop filter 33. The electrical signal obtained by converting the optical signal transmitted from the transmission device 1 in the optical / electrical conversion unit 15 of the reception device is compared with the phase of the clock output from the VCO 32 and passed through the loop filter 33. The voltage output to the VCO 32 is changed in accordance with the phase shift between the electric signal and the clock. The VCO 32 varies the clock frequency in accordance with the variation in the voltage output from the phase comparator 31. Here, when the phases of the electrical signal and the clock coincide, that is, synchronization is established, the voltage output from the phase comparator 31 becomes constant. Therefore, if the voltage at the point A becomes constant, the clock component is extracted from the data signal and synchronization is achieved.
[0024]
FIG. 3 is a flowchart of the sequence for detecting and displaying an abnormal part. First, when this sequence is started in step 1, the process proceeds to step 2, and the state of the DC component level of the optical signal received by the auxiliary signal detector 23 is shown. get. Subsequently, the process proceeds to step 3 to acquire the state of the AC component level of the optical signal received by the main signal detector 24. In step 4, the clock extraction unit 21 extracts a clock component from the data signal, and acquires information on whether or not synchronization has been achieved.
[0025]
In step 5, it is determined whether the DC component level of the received optical signal is normal or abnormal. For example, if the DC component level of the received optical signal is lower than the set threshold level and is abnormal, the process proceeds to step 6. In this state, it is considered that an optical space communication abnormality has occurred, so that no optical signal is output from the opposing device, or the optical signal emission direction of the opposing device is incorrect, or the optical signal incident method of the receiving device is It is displayed on the display unit 26 that an abnormality such as an inaccuracy or an obstruction in the optical wireless communication path has occurred.
[0026]
If it is determined in step 5 that the direct current component level of the light is higher than the set threshold level and is normal, the process proceeds to step 7 to determine whether the alternating current component level of the received optical signal is normal or abnormal. For example, if the AC component level of the received optical signal is lower than the set threshold level and is abnormal, the process proceeds to step 8. In this state, since it is possible to determine that the optical space communication is normal but there is no signal to be transmitted, the display unit 26 displays that an abnormality has occurred in which transmission data is not input to the opposite device.
[0027]
If it is determined in step 7 that the AC component level of the light is higher than the prescribed threshold level and is normal, the process proceeds to step 9 where a clock component is extracted from the data signal and it is determined whether or not synchronization is achieved. To do. If synchronization is not achieved and data cannot be regenerated, the process proceeds to step 10. Since it can be determined that there is a problem with the clock frequency of the data to be transmitted in this state, the transmission data input to the opposite device is incorrect, or an abnormality has occurred in which the data rate of the transmission data input to the opposite device is incorrect. Is displayed on the display unit 26.
[0028]
If the clock component is extracted from the data signal in step 9 and the data can be regenerated with synchronization, the process proceeds to step 11 to display on the display unit 26 that the data transmission is normally transmitted. The process proceeds to the next step 12. In step 12, information on the DC component level of the received optical signal is displayed. Further, when an abnormal display is made in steps 6, 8, and 10, the process proceeds to step 12. Subsequently, the process proceeds to step 13 where information on the AC component level of the received optical signal is displayed, and information on whether or not the clock component is extracted from the data signal and data can be regenerated in step 14 is displayed. Returning to step 2, the same processing is repeated below.
[0029]
In FIG. 4, when the state of the direct current component level, the state of the alternating current component level, and the state of whether or not synchronization is obtained by extracting the clock component from the data signal are changed, both the generation time and the change information are stored as log information. The system block diagram for this is shown.
[0030]
The DC component level state, the alternating current component level state, the clock component is extracted from the data signal, and the state of whether or not the synchronization is achieved is analyzed by the CPU 41. The direct current component level detector 42, the alternating current component level detector 43, The outputs of the clock extraction unit 44 and the clock 45 are connected. Further, the CPU 41 is connected to a data storage unit 46 composed of, for example, a flash ROM, a RAM or the like. The clock 45 can also be built in the CPU 41.
[0031]
DC component level information in the received optical signal detected by the DC component level detection unit 42 is output to the CPU 41, and similarly, AC component level information of the optical signal detected and received by the AC component level detection unit 43, a clock extraction unit Information on whether or not the data detected in 44 has been regenerated is also output to the CPU 41. The CPU 41 extracts the clock component from the DC component level, the AC component level, and the data signal, analyzes the state of whether or not synchronization has been performed, and from the DC component level detection unit 42, the AC component level detection unit 43, and the clock extraction unit 44. When each information changes, that is, when it changes from normal to abnormal or from abnormal to normal, the current time is read from the clock 45, and the information of the item whose state has changed and the occurrence time are stored in the data storage unit 46.
[0032]
FIG. 6 is a flowchart of the log information storage sequence in FIG. 5. First, when this sequence is started in step 21, information on the direct current component level of the optical signal received by the direct current component level detector 42 is acquired in step 22, and the process proceeds to step 23. In step 23, a change in the state of the DC component level in the received optical signal is determined. When the state changes, that is, when the normal state changes to the abnormal state, or changes from the abnormal state to the normal state, the process proceeds to Step 24, where the current time is obtained from the clock 45, and then the current time and the received direct current in Step 25. The component level information is saved and the process proceeds to step 26. If it is determined in step 23 that the state of the DC component level of the received optical signal has not changed, the process proceeds to step 26.
[0033]
In step 26, information on the AC component level of the optical signal received by the AC component level detector 43 is acquired, and the process proceeds to step 27. In step 27, a change in the state of the AC component level in the received light is determined. If the state changes, that is, if the normal state changes to the abnormal state, or changes from the abnormal state to the normal state, the process proceeds to step 28, where the current time is obtained from the clock 45, and then the current time and the received AC in step 29. The component level information is saved, and the process proceeds to Step 30. If it is determined in step 27 that the AC component level in the received optical signal has not changed, the process proceeds to step 30.
[0034]
In step 30, the AC component level detection unit 43 extracts the clock component from the data signal to acquire information on whether or not synchronization is achieved, and the process proceeds to step 31. In step 31, a clock component is extracted from the data signal to determine a change in state as to whether synchronization has been achieved. When the state changes, that is, when the normal state changes to the abnormal state, or changes from the abnormal state to the normal state, the process proceeds to step 32, where the current time is obtained from the clock 45, and subsequently, in step 33, the current time and the data signal are obtained. The clock component is extracted and the state as to whether or not synchronization is established is stored, and the process returns to step 22 to repeat this sequence. Further, when it is determined in step 31 that a clock component is extracted from the data signal and the state of whether or not synchronization is achieved does not change, the process returns to step 22 and this sequence is repeated below.
[0035]
FIG. 6 shows a configuration diagram of a mechanism for transmitting a DC component level state, an AC component level state, a clock component from a data signal, and transmitting information about whether synchronization has been established or not to an external terminal. The CPU 51 that analyzes the state, the state of the AC component level, the information on whether or not the clock component is extracted from the data signal, and the synchronization is analyzed. The DC component level detection unit 52, the AC component level detection unit 53, the clock extraction unit 54, The output of the clock 55 is connected Has been . Further, the CPU 51 is connected with a data storage unit 56 and a communication driver 57 which are composed of, for example, a flash ROM, a RAM and the like.
[0036]
The communication driver 57 is connected to a status display terminal 59 such as a personal computer placed at a remote location via a communication line 58. The communication line between the communication driver 57 and the terminal 59 is a local connection such as a network or RS-232C. This clock 55 can also be built in the CPU 51.
[0037]
DC component level information of the received optical signal detected by the DC component level detection unit 52 is output to the CPU 51, and similarly, AC component level information of the received optical signal detected by the AC component level detection unit 53, clock extraction unit Information on whether or not the data detected in 54 can be regenerated is also output to the CPU 51. The CPU 51 reads the current time from the clock 55 when each information changes from the DC component level detection unit 52, the AC component level detection unit 53, and the clock extraction unit 54, that is, when the information changes from normal to abnormal or from abnormal to normal. The changed item information and the occurrence time are stored in the data storage unit 56.
[0038]
When the CPU 51 detects that each information has changed from the DC component level detection unit 52, the AC component level detection unit 53, and the clock extraction unit 54, the CPU 51 creates a data string based on the information of the changed item and the generation time based on a predetermined format. The created data string is transmitted to the communication driver 57. The communication driver 57 that has received the data string transmits the data string received from the CPU 51 to the terminal 59 via the communication line 58.
[0039]
In addition, the user of the terminal 59 receives the state of the DC component level of the received optical signal, the state of the AC component level of the received optical signal, information on whether the clock component is extracted from the data signal, and data storage. When making an acquisition request for any of the information stored in the unit 56, an information acquisition request based on a predetermined format is transmitted to the communication driver 57 via the communication line 58. Upon receiving the information acquisition request from the terminal 59, the communication driver 57 transmits this information acquisition request to the CPU 51.
[0040]
When the CPU 51 receives this information acquisition request, the received information acquisition request extracts the clock component from the DC component level state of the received optical signal, the AC component level state of the received optical signal, and the data signal, and is it synchronized? Whether or not information stored in the data storage unit 56 is identified. In the case of the DC component level state of the received optical signal, information on the DC component level of the received optical signal is obtained from the DC component level detector 52, and in the case of the AC component level state of the received optical signal. The information on the AC component level of the optical signal received from the AC component level detection unit 53 is obtained, and in the case of information indicating whether or not synchronization is obtained by extracting the clock component from the data signal, the information from the clock extraction unit 54 in the data signal is obtained. Information on whether or not synchronization is obtained by extracting the clock component is obtained, and in the case of the information saved in the data storage unit 56, the information saved from the data storage unit 56 is obtained, and the obtained information is converted into a predetermined format. A base data string is created, and the created data string is transmitted to the communication driver 57. The communication driver 57 that has received the data string transmits the data string to the terminal 59 via the communication line 58.
[0041]
FIG. 7 shows a flowchart of a communication sequence when the state changes. First, when this sequence is started in step 41, the DC component level information of the optical signal received by the DC component level detector 52 is acquired in step 42, and the process proceeds to step 43. If the state of the DC component level of the received optical signal changes when moving to step 43, that is, if the state changes from the normal state to the abnormal state, or changes from the abnormal state to the normal state, the process proceeds to step 44, and the current time is acquired from the clock 55, The process proceeds to step 45, where the current time and the received DC component level information are transmitted to the terminal 59, and the process proceeds to step 46.
[0042]
If it is determined in step 43 that the state of the DC component level of the received optical signal has not changed, the process proceeds to step 46. In step 46, information on the AC component level of the optical signal received by the DC component level detector 52 is acquired, and the process proceeds to step 47. If the state of the AC component level of the received optical signal changes when the process proceeds to step 47, that is, if the state changes from the normal state to the abnormal state or from the abnormal state to the normal state, the process proceeds to step 48, and the current time is acquired from the clock 55. 49, the current time and the received AC component level information are transmitted to the terminal 59, and the process goes to Step 50.
[0043]
If it is determined in step 47 that the AC component level of the received optical signal has not changed, the process proceeds to step 50. In step 50, the clock extraction unit 54 extracts the clock component from the data signal to acquire information on whether or not synchronization has been obtained, and the process proceeds to step 51 to change the state of whether or not the synchronization extracted by the clock component has been achieved. to decide. When the synchronization state of the clock component changes, that is, when the normal state changes to the abnormal state or changes from the abnormal state to the normal state, the process proceeds to step 52, the current time is acquired from the clock 55, and the current processing is performed in step 53. A clock component is extracted from the time and the data signal, and the status of whether or not synchronization is achieved is transmitted to the terminal 59, and the process returns to step 42, and this sequence is repeated thereafter. In step 51, even if there is no change in state, the process returns to step 42, and this sequence is repeated thereafter.
[0044]
FIG. 8 is a flowchart of a sequence when an information acquisition request is received from a terminal. In step 61, when an information acquisition request from the terminal 59 is received, the process proceeds to step 62, and it is determined whether or not the received information acquisition request is an information acquisition request for the DC component level of the received optical signal. In the case of a DC component level information acquisition request, the process proceeds to step 63, where the DC component level information of the received optical signal is acquired. In step 64, the DC component level information of the optical signal acquired in step 63 is transmitted to the terminal 59. Send to step 65. If the information acquisition request received from the terminal 59 in step 62 is not an information acquisition request for the DC component level of the received optical signal, the process proceeds to step 65.
[0045]
In step 65, it is determined whether or not the information acquisition request received from the terminal 59 is an AC component level information acquisition request for the received optical signal. In the case of an AC component level information acquisition request, the process proceeds to step 66, where AC component level information of the received optical signal is acquired, and in step 67, the AC component level information of the optical signal acquired in step 66 is obtained from the terminal 59. To step 68. If the information acquisition request received in step 65 is not an AC component level information acquisition request for the received optical signal, the process proceeds to step 68.
[0046]
In step 68, it is determined whether or not the information acquisition request received from the terminal 59 is an information acquisition request for extracting a clock from the data signal and synchronizing. In the case of an information acquisition request indicating whether synchronization has been achieved, the process proceeds to step 69 where a clock is extracted from the data signal to acquire information regarding whether synchronization has been achieved, and in step 70, the clock is extracted from the data signal acquired in step 69. Is extracted and information on whether or not synchronization is obtained is transmitted to the terminal 59 and the process proceeds to Step 71. On the other hand, if the information acquisition request received in the process of step 68 is not an information acquisition request indicating whether the clock is extracted from the data signal and synchronized, the process proceeds to step 71.
[0047]
In step 71, it is determined whether the information acquisition request received from the terminal 59 is a stored log information acquisition request. In the case of a log information acquisition request, the process proceeds to step 72, the stored log information is acquired, the process proceeds to step 73, the stored log information acquired in step 72 is transmitted to the terminal 59, the process proceeds to step 74, and this sequence is completed. To do. Further, even when the information acquisition request received in the process of step 71 is not a saved log information acquisition request, the process proceeds to step 74 and this sequence is terminated.
[0048]
【The invention's effect】
As described above, the optical space transmission device according to the present invention can quickly identify the location where an abnormality has occurred in the optical space transmission device. From the above, it is possible to investigate the cause of communication abnormality between optical space communications. Furthermore, by sending these pieces of information to a remote place, it is possible for the service person and the user to investigate the cause of the abnormality from a place away from the optical space transmission device.
[0049]
Here, when the direct current component level of the optical signal received from the opposing device is abnormal, it can be determined that an abnormality has occurred in the optical space communication. Therefore, no optical signal is output from the opposing device. It can be understood that an abnormality has occurred on the optical space radio, for example, because the direction is not correct, the optical signal incident direction of the receiver is not correct, or there is a shielding object including weather deterioration in the optical wireless communication path.
[0050]
If the AC component level of the optical signal received from the opposite device is abnormal, it is considered that the transmission data is not input to the opposite device, and the interface between the devices outputting the transmission data It can be seen that an abnormality has occurred.
[0051]
If the clock component cannot be extracted from the data signal and synchronization is not achieved, it is considered that there is a problem with the clock frequency of the transmitted data, so the transmission data input to the opposite device is incorrect, or the opposite device It can be considered that the cause is that the data rate of the transmission data input to the device is not correct, and it is understood that an abnormality has occurred in the device outputting the transmission data to the opposite device. This makes it possible for the user to determine where the abnormal point is, reducing the need for unnecessary service personnel, and reducing the load on the service personnel because there is no need for special equipment such as an error rate measuring instrument. . In addition, since the location of the abnormality can be identified at a glance, a quick response can be performed, thereby minimizing the time from occurrence of the abnormality to recovery.
[0052]
Further, when the above information changes, the information is stored together with the time of occurrence. This function makes it possible to verify later when and where an abnormality has occurred, and to quickly investigate the cause of the abnormality and take countermeasures.
[0053]
In addition, since it has a function of transmitting the above information and the stored information to an external terminal, it is possible to know the state of communication abnormality at a remote place without going to a place where the receiving device is located, so that a service person can It is possible to know the status of the optical space communication device from a remote location, and to quickly take an appropriate response from the information.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an optical space transmission apparatus.
FIG. 2 is a configuration diagram of a clock extraction unit.
FIG. 3 is a flowchart of an abnormal part detection and display sequence.
FIG. 4 is a configuration diagram of a system for storing log information.
FIG. 5 is a flowchart of a log information storage sequence.
FIG. 6 is a configuration diagram of a mechanism for transmitting information to an external terminal.
FIG. 7 is a flowchart of a communication sequence when a state changes.
FIG. 8 is a flowchart of a sequence when an information acquisition request is received.
[Explanation of symbols]
1 Transmitter
2 Receiver
3 Main signal input section
4 Auxiliary signal generator
5 multiplexing part
6 Electricity / light conversion part
7 Laser drive circuit
8 Laser diode
9, 10, 11, 12, 13, 14 Lens
15 Optical / electrical converter
16 Light receiving element
17 Light receiving circuit
18 Amplifier
19 Filter for auxiliary signal extraction
20 Main signal extraction filter
21 Clock extractor
22 Waveform shaping part
23 Auxiliary signal detector
24 Main signal detector
25 CPU
26 Display section
27 Signal output section

Claims (3)

An optical space transmission device that transmits and receives information using optical wireless with an opposing device arranged to face each other at a predetermined distance,
A conversion unit that receives an optical signal generated by combining the main signal and the auxiliary signal from the opposing device and converts the optical signal into an electrical signal;
DC component level detection means for extracting an auxiliary signal component of the optical signal from the electrical signal by an auxiliary signal extraction filter and detecting a DC component level of the auxiliary signal component ;
A DC component level determination means for DC component level of the current optical signal from the DC component level to determine whether it is normal,
AC component level detection means for extracting a main signal component of the optical signal from the electrical signal by a main signal extraction filter and detecting an amplitude level of the main signal component ;
And AC component level determination means for determining whether the amplitude level of the current main signal component is normal from the amplitude level,
Clock component extraction means for extracting a clock component from the electrical signal;
Synchronization determination means for determining whether or not the clock component could be extracted by the clock component extraction means;
An optical space transmission apparatus comprising: a direct current component level determination means; an alternating current component level determination means; and a display means for displaying determination information by the synchronization determination means.   Means for knowing the time, and when the judgment result of the DC component level judgment means, the AC component level judgment means, and the synchronization judgment means has changed, has a storage means for saving the changed state and the changed time. The optical space transmission device according to claim 1.   The optical space transmission apparatus according to claim 2, further comprising a transmission unit configured to transmit information stored in the storage unit to an external terminal.

Images