JP2000341198A - Radio communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To economically build up network system of radio communication within a prescribed area and to enhance the communication efficiency and the utilization efficiency of the entire system by improving the maintenance management function for a plurality of slave stations dotted in the area so as avoid wasteful accesses. SOLUTION: A master station and a plurality of radio slave stations, dotted within a prescribed area that mutually transmit communication data via a radio wave using free space for a transmission medium each have a plurality of sets of communication path information from its own station over a final transmission station, on which priority is placed. The master station is provided with a function of supervising the state of a plurality of the slave stations and a state of communication paths through the transmission of a maintenance use test signal, and each slave station is provided with a function of deleting information of the communication path where a communication fault is taking place.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to centrally monitor the operation status of, for example, manhole pumps installed at a plurality of locations in drainage pipes and equipment installed at a plurality of locations in an automation factory. In addition, the present invention relates to a wireless communication system applied to a case where the operation of manhole pumps and equipment at a plurality of locations is controlled by a command from a central control office. So that various types of communication data are transmitted between the plurality of wireless slave stations and the master station and between the plurality of wireless slave stations via radio waves using free space as a transmission medium. The present invention relates to a wireless communication system that has been used.

[0002]

2. Description of the Related Art This type of radio communication system uses free space as a transmission medium and does not require long continuous wired facilities between radio stations. Of course, it is possible to easily create communication lines even in a large city where it is difficult to lay cable facilities due to an increase in underground facilities and traffic conditions, etc. It has the advantage that it can be restored quickly with equipment, and the entire communication line can be significantly reduced in cost compared to the wired method.

[0003] When introducing wireless communication using free space as a transmission medium, in order to prevent mutual interference with radio communication radio waves used by many organizations such as electric power companies, electric railway companies, broadcasting companies and police. The transmission law and the modulation method are regulated by the Radio Law. Therefore,
In order to obtain a wireless communication system over a wide range, it is necessary to increase the transmission output, but the transmission output cannot be freely selected, which limits the expansion of communication capacity and communication range. ing.

[0004] Under such circumstances, as a wireless communication system that secures a communication line over a relatively wide and long range, relay stations are installed at regular intervals determined by the transmission output, and the communication from each wireless station is performed. A relay-type wireless communication system in which a radio wave attenuated by transmission is amplified by a relay station and then sent to the next relay station is considered. In this relay-type wireless communication system, a relay transmitting / receiving device (repeater) such as a relay is used. Not only does the bureau's equipment require significant startup costs,
In many cases, a relay station is installed in a remote place on a mountain, etc. in order to increase the line-of-sight distance, which requires considerable labor and cost for patrol maintenance and the like. In particular, when wireless communication is networked within a certain area, the relay type system has major problems in terms of economy, maintenance, etc., and there is a technical problem that it is not possible to sufficiently secure the advantage compared with the wired type. .

[0005] In view of the above, the present applicant assigns each of a plurality of radio slave stations scattered in a certain area to play a role of a relay station, so that a plurality of radio slave stations and a master station are interposed. A wireless communication system in which a plurality of communication lines capable of transmitting communication data via radio waves using free space as a transmission medium has been previously proposed and a patent application has been filed. According to the wireless communication system proposed by the applicants of the present application, even between wireless stations located at a distance apart from each other that cannot directly communicate with each other (between a master station and a slave station or between slave stations), It is possible to transmit data for communication by using a wireless slave station located in the middle as a relay station, and there is an advantage that a wireless communication network can be economically constructed as compared with the above-mentioned relay system.

In the wireless communication system proposed by the applicants of the present invention, a master station and a plurality of wireless slave stations each have a communication path in which a priority is assigned to a next transmitting station. For example, the communication data transmitted from the own station is first transmitted to one higher-ranking slave station, and if there is no response signal from the transmitting slave station, the priority order is lower. Each of a plurality of wireless slave stations existing from the originating station to the final destination transmitting station determines the next one transmitting slave station based on the priority order, such as switching to transmission to the next slave station. However, the communication data is transmitted to the final transmitting station.

[0007]

However, in the wireless communication system having the above-described configuration, a plurality of wireless slave stations exist between a communication data transmitting station and a final transmitting station, and the plurality of wireless slave stations exist. When communication must be performed with a wireless slave station as a relay station, communication between the originating station and the next wireless slave station and between wireless slave stations cannot be confirmed, such as the presence or absence of a response signal. Since it is necessary to repeatedly determine the next one wireless station based on the result, it may take time to communicate to the final transmitting station, and while highly reliable communication is possible, communication efficiency is improved. In addition, there is room for improvement in the use efficiency of the entire system.

[0008] The present invention has been made in view of the above-mentioned circumstances, and not only can a communication line networked within a fixed area over a relatively wide and long area be constructed economically, but also the communication efficiency and the system can be improved. To provide a communication system capable of remarkably improving the overall use efficiency, and furthermore, rationally and efficiently monitoring a plurality of scattered radio stations and communication lines to ensure an excellent maintenance management function. It is an object.

[0009]

In order to achieve the above object, a radio communication system according to the present invention is provided between a master station and a plurality of radio stations scattered in a certain area and a plurality of radio stations. Are configured to be able to transmit communication data via radio waves using free space as a transmission medium, and transmitted to a plurality of wireless slave stations from a master station and a slave station other than the own station, respectively. It is determined whether the received communication data is addressed to the own station or to another station, and when it is determined that the communication data is addressed to the other station, the own station is received as a relay station. Means for transferring communication data to one of the other stations, and each of the master station and the plurality of wireless slave stations has a priority ranging from its own station to the last transmitting station, and Wireless communication system having a plurality of communication path information with The master station monitors the state of the plurality of wireless slave stations and the state of the plurality of communication paths by transmitting a maintenance test signal to the plurality of wireless slave stations periodically or irregularly. In addition, there is provided a means for reporting the monitoring information on a maintenance test signal to each of the wireless slave stations.

According to the present invention having the above-described structure, a plurality of wireless slave stations scattered in a fixed area serve as relay stations, and a communication line networked over a relatively large and long range is constructed. Therefore, even if each station exists in a positional relationship where direct communication cannot be performed between the master station and a plurality of wireless slave stations and between the wireless slave stations due to transmission output restrictions, the relay transmitting / receiving apparatus (relay). Wireless communication between any of the wireless slave stations in the above-mentioned fixed area and between the wireless slave stations and the master station without the need for installing a special relay station having Regardless, it is possible to economically construct a wireless communication network.

In addition, since each of the master station and the plurality of wireless slave stations has a plurality of pieces of communication route information from the own station to the last transmitting station and assigned priorities, the higher order of the priorities is given. If there is no response signal from any one of the plurality of slave stations existing in the communication path and communication becomes impossible or communication error occurs, the next station from the own station to the last transmission station Since it is possible to immediately switch to the communication path of the priority order and perform communication, each station checks the communication status of the next transmitting slave station, and based on the check result and the priority, the next one wireless slave station As compared with the method of performing a repetitive operation such as determining the transmission delay, transmission delay compensation for shortening the communication time to the final transmitting station is possible, and the communication efficiency and the use efficiency of the entire system can be improved.

[0012] In addition, a maintenance test signal is transmitted from the master station to each wireless slave station periodically or irregularly at a rate of once to several times a day, for example. It is possible to centrally monitor the status of the station and the status of a plurality of communication paths on the master station side, and to report the monitoring information on a maintenance test signal to each of the wireless slave stations to notify the individual wireless slave stations. However, knowing the status of each wireless slave station and the status of a plurality of communication paths, it performs rational and efficient maintenance such as maintenance and inspection and repair of not only its own station but also other nearby stations before a communication error occurs. This makes it possible to enhance the maintenance management function for interspersed wireless slave stations and communication paths.

[0013] In particular, when a maintenance test signal reported from the master station is received at each wireless slave station, communication abnormality information is included in the monitoring information included in the test signal. Means for determining whether or not communication path information is included, and when it is determined that communication error information is included, communication path information in which a communication error has occurred from a plurality of communication path information held by the own station. By adopting a configuration in which a means for erasing is provided, in data communication after a communication error has occurred, communication is performed without unnecessary access to a wireless slave station having the communication error and a communication path including the station. The efficiency and use efficiency of the entire system can be further improved.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a wireless communication system according to the present invention. In FIG. 1, reference numeral 1 denotes one wireless master station connected to the central monitoring device 3, and 2A to 2I are respectively scattered in a certain area. A plurality of wireless slave stations attached to a plurality of equipment (not shown) such as a manhole pump, including a master station 1 and slave stations 2A to 2A.
It is configured to be able to transmit communication data by radio waves using free space as a transmission medium between the communication station I and the slave stations 2A to 2I.

The master station 1 and a plurality of wireless slave stations 2A to 2I
Has an identification number ID, and has a plurality of pieces of communication path information from the own station to the last transmitting station, and the plurality of pieces of communication path information are given priorities in advance. . That is, as shown in the data format of FIG. 2, the data D1 for operation control and failure occurrence of the manhole pump and the equipment and the local station which is the source, the other child station which becomes the relay station, and the child which becomes the transmission destination The communication data D into which the address information ADR of the station or the master station is inserted is input.

For example, the wireless slave station 2A will be described in detail.
The wireless slave station 2A has a plurality of pieces of communication path information assigned with priorities as shown in Table 1. In the communication path having the highest priority, that is, the communication path having the priority (1), the own station 2A
The communication data D including the data D1 and the address information ADR are sequentially transferred from the slave station 2E to the slave station 2H using the relay station and transmitted to the master station 1, and include the data D1 of the master station 1 and the address information ADR. The communication data D is sequentially transferred using the slave station 2H → the slave station 2E as a relay station and transmitted to the own station 2A. In the communication path of priority (2), the communication data D of the own station 2A is the slave station. 2B → slave station 2F → slave station 2I is sequentially transferred and transmitted to master station 1, and communication data D of master station 1 is slave station 2I → slave station 2F → slave station 2B as a relay station. The data is sequentially transferred and transmitted to the own station 2A.

[0017]

[Table 1]

As shown in FIG. 3, the master station 1 inserts data D1 for operation control and the address information ADR of its own station, the relay slave station and the last transmitting station, which are the transmission source, and performs the communication procedure. A communication data creating unit 4 for creating communication data D having a format as shown in FIG. 2 and generating a maintenance test signal, and the communication data D
And converting (modulating) the maintenance test signal into a signal suitable for transmission by radio waves, and converting the communication data D when receiving the communication data D transmitted from the wireless slave stations 2H and 2I. A signal converter 6 for demodulating and outputting the data to the data output unit 5, and the radio waves of the communication data D and the maintenance test signal are transmitted to the wireless slave stations 2H and 2I via the antenna 7; Those wireless slave stations 2H, 2
A radio unit 8 for receiving the communication data D transmitted from I and a response signal to the maintenance test signal, and a communication for controlling the operations of the signal conversion unit 6 and the radio unit 8 to perform transmission / reception control And a control unit 9.

On the other hand, each of the above-mentioned wireless slave stations 2A to 2I
As shown in FIG. 5, a measuring unit 11 for measuring contact data or analog data, and failure occurrence data D1 when it is detected that a failure has occurred in a contact or equipment based on the data measured by the measuring unit 11. And the address information ADR of each of the own station as a transmission source, another slave station as a relay station, and the last transmission station are inserted to create communication data D in a format as shown in FIG. ,
A communication data creation unit 12 for creating a response signal to the maintenance test signal transmitted from the master station 1, and the communication data D and the response signal are transmitted (transmitted) by radio waves.
Is converted (modulated) to a signal suitable for
And a signal converter 13 for converting (demodulating) the received communication data D and maintenance test signal when receiving the communication data D and the maintenance test signal transmitted from another slave station. A radio unit 15 for transmitting and receiving the radio waves of the communication data D and the maintenance test signal via the antenna 14, and a communication control for controlling the operations of the signal conversion unit 13 and the radio unit 15 to perform transmission and reception control. Part 1
6 is provided.

Each of the wireless slave stations 2A to 2I has a master station 1
When the test signal for maintenance transmitted from is received, it is determined whether or not the communication abnormality information is included in the monitoring information transmitted on the test signal, and the communication abnormality information is included. When it is determined that there is a communication station, there is provided a function of deleting communication path information including a slave station having a communication error from a plurality of pieces of communication path information of the own station.

Next, the normal communication operation of the wireless communication system having the above configuration will be described with reference to the flowchart of FIG. For example, taking the wireless slave station 2A as an example, a case where transmission from the wireless slave station 2A is necessary is as follows.
(A) When it is detected that a failure has occurred in a contact point or a device to be measured based on the measurement data in the measurement unit 11 in the own station 2A, the failure occurrence data D1 is transmitted to the master station 1 using the own station 2A as a source. And (b) comparing the address information ADR in the communication data D transmitted from another station and received by the own station 2A with the address information ADR of the own station 2A. The data D is determined to be data that needs to be relayed to another station. In the wireless slave station 2A, the case requiring transmission is first determined by any of the above (a) and (b). It is determined whether this is the case (step S20).

If the result of the determination is (a), the wireless slave station 2A checks the priorities of a plurality of communication paths from its own station 2A to the master station 1 which is the last transmitting station (step S21). Then, the communication data creation unit 4 uses the measurement unit 11
The local station 2A in the failure occurrence data D1 and another slave station 2 existing in the communication path of the priority (1) and serving as a relay station
E, 2H and the address information ADR of each of the master stations 1 are inserted to create communication data D in a format compatible with the communication procedure, and the communication data D
3 is converted (modulated) by the antenna 14 of the radio unit 15
Is transmitted to free space by radio waves, and the slave station 2E as the next destination is called (steps S22 and S23).

The slave station 2E called by the above transmission radio wave
Determines whether the address information ADR in the received communication data D matches the address information ADR of the own station 2E and returns a response signal to the slave station 2A of the transmission source when the address information ADR matches. Then, a communication link between the two stations 2A and 2E is established by the communication link processing between the two stations 2A and 2E.
Transmission (transfer) of the communication data D from the wireless unit 15 of the transmission source slave station 2A to the slave station 2E is performed (step S24).
To S28). The communication between the slave station 2E that has received the communication data D and the next slave station 2H is also performed through the same step operation as described above. Is also performed through the same step operation as described above.

In the communication operation as described above, the slave station 2
E, 2H or a response signal is not returned from the master station 1, a communication link is not established, or
If an error occurs in communication on the communication path of the priority (1) such as when the communication link is established but transmission of all communication data D is not completed, the error information is transmitted to the child station serving as the originating station. After returning to the station 2A to check the priority of the next communication path and confirm the existence of the next communication path, the flow returns to step S22, and the relay station address information ADR in the communication data D is changed to the next priority (2 ) Creates communication data D in which address information of each of the other slave stations 2B, 2F, 2I and master station 1 existing in the communication path is rewritten, and converts this signal into a signal. The signal is retransmitted to the free space by radio waves via the antenna 14 and finally transmitted to the master station 1 (steps S29 and S30).

On the other hand, if the result of the determination in step S20 is (b), the wireless
After searching for the next transmitting station and confirming the existence of the next transmitting station based on the relay station address information ADR in the above, the next transmitting slave station 2E is called (steps S31 to S33), and thereafter, the above-described steps are performed. Communication is performed up to the master station 1 through the operations (S24 to S30).

In the master station 1 that finally receives the communication data D, the received communication data D is converted (demodulated) by the signal conversion unit 6, and then output to the data output unit 5, and The generated wireless slave station is notified to the central monitoring device 3.

It should be noted that the above description is based on the wireless slave stations 2A to 2A.
2I is a description of a communication operation when transmitting communication data D including the failure occurrence data D1 from one of the wireless stations 2A to 2I to the master station 1. Since the communication operation when transmitting the communication data D including the operation control data D1 of the manhole pump and the equipment is the same as described above, the description is omitted.

In the wireless communication system having the above-described configuration, the communication from the master station 1 to the plurality of wireless slave stations 2A to 2I is performed periodically or irregularly at a rate of once to several times a day, for example. By transmitting the maintenance test signal using the route, the statuses of the wireless slave stations 2A to 2I and the communication route are monitored, and the monitoring information is put on the maintenance test signal and transmitted to each of the wireless slave stations 2A to 2I. A monitoring function by transmitting a maintenance test signal will be described below with reference to the flowcharts of FIGS. 6 and 7.

First, from the master station 1, as shown in FIG.
Maintenance test signal has priority (1) at any timing
Is transmitted to the wireless slave station by using the communication path, and the presence or absence of a response signal from the slave station is determined. Here, if there is a response signal from the slave station that transmitted the test signal, the next slave station is checked, a maintenance test signal is transmitted to that slave station, and if there is no response signal, the After adding the identification number ID of the non-responding slave station to the maintenance test signal, the next slave station is checked and the maintenance test signal is transmitted. By sequentially transmitting signals, the master station 1 intensively monitors the statuses of the plurality of wireless slave stations 2A to 2I and the communication path, and also monitors the ID of the slave station having no response, that is, the monitoring information including the communication abnormality information. Is transmitted to each of the wireless slave stations 2A to 2I (steps S40 to S44).

On the other hand, as shown in FIG. 7, when each of the wireless slave stations 2A to 2I receives the maintenance test signal transmitted from the master station 1, the monitoring information added to the test signal includes It is determined whether or not there is a response-free slave station ID in which a communication error has occurred. If not, a response signal to that effect is returned to the master station 1; After erasing the communication path information including the slave station in which the communication abnormality has occurred from the path information, a response signal is returned to the master station 1 (steps S50 to S53).

By performing the monitoring operation by transmitting the maintenance test signal as described above, the master station 1 centrally monitors the states of the plurality of scattered wireless slave stations 2A to 2I and the states of the plurality of communication paths. In addition, the individual wireless slave stations 2A to 2I can know not only the status of their own station but also the status of other slave stations, and can perform maintenance such as maintenance and inspection and repair rationally before a communication error occurs. The maintenance management function of the entire networked communication system can be enhanced. In addition, when a communication error occurs, the communication abnormal station and the communication path information including the station are deleted, so that unnecessary access can be eliminated in the subsequent data communication to improve the communication efficiency and the use efficiency of the entire system. it can.

[0032]

As described above, according to the present invention, a plurality of wireless slave stations scattered in a certain area are configured to play the role of a relay station. Without requiring the installation of a special relay station equipped with a mobile device, etc., and enables wireless communication between all slave stations and the master station within a certain area, despite the fact that the transmission output is regulated by the Radio Law A wireless communication network system can be constructed very economically. In addition, since each of the master station and the plurality of wireless slave stations has a plurality of pieces of communication path information from the own station to the last transmitting station and assigned a priority, each of the slave stations constituting each communication path In the case where even one of the stations has a communication failure, communication failure or communication abnormality, it is possible to immediately switch to the next priority communication path from the own station to the final transmitting station and perform communication,
By shortening the communication time to the final transmitting station, the communication efficiency and the use efficiency of the entire system can be significantly improved.

In addition, a maintenance test signal is transmitted from the master station to each wireless slave station periodically or irregularly at a rate of, for example, once to several times a day, and each wireless slave station is networked. In addition to centrally monitoring the status of multiple communication paths and the status of multiple communication paths on the master station side, the monitoring information is included in the maintenance test signal and reported to each wireless slave station. , And the status of a plurality of communication paths, it is possible to perform maintenance and inspection of other stations nearby as well as the own station rationally and efficiently before a communication error occurs. This has the effect of improving the maintenance management function for scattered wireless slave stations and communication paths.

In particular, when a maintenance test signal reported from the master station is received by each wireless slave station, it is determined that communication abnormality information is included in the monitoring information included in the test signal. By providing a function to delete the communication path information in which a communication error has occurred from the multiple communication path information possessed by the own station, the communication error can be prevented during data communication after the communication error occurs. The communication efficiency and the use efficiency of the entire system can be further improved by eliminating unnecessary access to the generated wireless slave station and the communication path including the station.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an entire wireless communication system according to the present invention.

FIG. 2 is a format of communication data in the system.

FIG. 3 is a schematic configuration diagram of a master station in the same system.

FIG. 4 is a schematic configuration diagram of a wireless slave station in the same system.

FIG. 5 is a flowchart illustrating a normal wireless communication operation by the above system.

FIG. 6 is a flowchart illustrating a processing operation on a master station side in a monitoring processing operation by transmitting a maintenance test signal in the same system.

FIG. 7 is a flowchart illustrating a processing operation on a wireless slave station side in a monitoring processing operation by transmitting a maintenance test signal in the same system.

[Explanation of symbols]

 Reference Signs List 1 master station 2A to 2I wireless slave station 4,12 communication data creation unit 6,13 signal conversion unit 7,14 antenna 8,15 wireless unit 9,16 communication control unit D communication data

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Daisuke Hiraishi 2-35 Jinbucho, Yao-shi, Osaka Inside Kubota Kuhoji Plant (72) Inventor Yasunori Sueyoshi 2-35 Jinmucho, Yao-shi, Osaka Co., Ltd. F-term in Kubota Kupoji Temple (reference)

Claims (2)

[Claims] 1. Communication data is transmitted between a master station and a plurality of wireless slave stations scattered in a certain area and between the plurality of wireless slave stations via radio waves using free space as a transmission medium. In addition to being configured to be able to transmit, each of the plurality of wireless slave stations is determined whether communication data transmitted from the master station and slave stations other than the own station is addressed to the own station or to another station. Means for transferring the communication data received by itself as a relay station to one of the other stations if the received data is addressed to another station. A radio communication system in which each of the stations has a plurality of pieces of communication path information in a state ranging from the own station to the last transmitting station and has a prioritized priority. Sends a maintenance test signal to wireless slave stations periodically or irregularly Means for monitoring the states of the plurality of wireless slave stations and the states of the plurality of communication paths, and transmitting the monitoring information to a maintenance test signal to notify each of the wireless slave stations. Wireless communication system. 2. Upon receiving a maintenance test signal reported from a master station, each wireless slave station determines whether or not communication abnormality information is included in monitoring information included in the test signal. Means for determining, and means for erasing, when it is determined that communication error information is included, communication path information in which a communication error has occurred from a plurality of communication path information owned by the own station. The wireless communication system according to claim 1.