JP6122773B2 - Communication system, information processing apparatus, and communication method - Google Patents

Description

  Embodiments described herein relate generally to a communication system, an information processing apparatus, and a communication method.

  In recent years, there is a system that collects data of control systems such as power plants, transportation, chemical plants, or nuclear power, which are important social infrastructures, and uses them as big data for various types of analysis and utilization, leading to more efficient operation of the plant. On the other hand, a virus (worm) targeting a control system represented by STUXNET has been reported, and a communication method that can safely connect the data of the control system and utilize the data is required.

  Here, in view of communication security, in many cases, one side is a side that may be a dangerous threat, and the other side is a side that has something to protect. A general firewall (FW: FireWall) is often set by defining the outside (threat side) and the inside (side to be protected) based on the same concept, and in some cases, an intermediate zone (DMZ) is provided. There is a thing.

JP 2006-295649 A

  The IP protocol currently used for communication has the feature that the information processing apparatuses are equivalent so that they can communicate with each other in the same procedure, in addition to the known protocol itself. For this reason, if one communicating information processing device permits intrusion to a malicious person or software by hacking (cracking) or the like, even if there is a firewall (FW) between them, the other information processing device May affect the navel. In the case of FW, bi-directional communication is possible in principle, and even if access from the outside is restricted, there is a possibility that the security hole of the FW itself or the security hole of communication software may intrude inside. is there.

  In view of the above problems, an object of one embodiment of the present invention is to provide a communication system, an information processing device, and a communication method that can improve the safety of communication.

A communication system according to an embodiment of the present invention includes a first information processing apparatus and a second information apparatus connected to the first information processing apparatus by a cable that conforms to an interface protocol that can be transmitted only from the first information processing apparatus. And an information processing device.
The second information processing apparatus has a shared storage unit that can store data, and a public driver storage that stores a public driver that enables the shared storage unit to be read and written from the first information processing apparatus using an interface protocol. A public driver execution unit that reads and executes a public driver from the public driver storage unit, and a reception processing unit that reads data stored in the shared storage unit. The first information processing apparatus includes: an access driver storage unit that stores an access driver for accessing a shared storage unit that is disclosed by a public driver using an interface protocol; and a shared storage unit that transmits transmission data and the transmission data. By reading and executing the access driver from the access driver storage unit, the transmission unit can read and write the shared storage unit via the cable. An access driver execution unit. The transmission unit determines whether or not the completion data is stored in the shared storage unit. If the completion data is not stored, the transmission unit stores new transmission data in the shared storage unit, and after the new transmission data is stored Save the completion data in the shared storage unit. The reception processing unit determines whether or not the completion data is stored in the shared storage unit. If the completion data is stored, the reception processing unit reads the transmission data from the shared storage unit, and after the reading is completed, the transmission data and the completion data are read. Is deleted from the shared storage unit.

It is a schematic block diagram which shows the structure of the communication system 101 in 1st Embodiment. FIG. 7 is a table T1 showing a connection diagram between terminals of the USB cable 3 and an example of pin arrangement of a Type A USB connector. 4 is a flowchart illustrating a schematic example of processing of a transmission unit 4 of the first information processing apparatus 1 and a reception processing unit 5 of the second information processing apparatus 2 in the first embodiment. It is a schematic block diagram which shows the structure of the communication system 101a in the modification of 1st Embodiment. It is a schematic block diagram which shows the structure of the communication system 102 in 2nd Embodiment. It is a flowchart which shows the schematic example of the process of the transmission part 4b of the 1st information processing apparatus 1b in 2nd Embodiment, and the reception process part 5b of the 2nd information processing apparatus 2b. It is a schematic block diagram which shows the structure of the communication system 103 in 3rd Embodiment. It is a flowchart which shows the schematic example of the process of the transmission part 4c of the 1st information processing apparatus 1c in 3rd Embodiment, and the reception process part 5c of the 2nd information processing apparatus 2c. It is a schematic block diagram which shows the structure of the communication system 104 in 4th Embodiment. It is a schematic block diagram which shows the structure of the communication system 105 in 5th Embodiment. It is a schematic block diagram which shows the structure of the communication system 106 in 6th Embodiment. It is a schematic block diagram which shows the structure of the communication system 107 in 7th Embodiment.

First, items common to the embodiments will be described.
In each embodiment, paying attention to the fact that information processing apparatuses (computers) in the IP protocol causing communication vulnerability are equivalent to each other, communication between information processing apparatuses is not equivalent to each other, for example, one is a host Thus, secure communication is realized by using a protocol in which one of the targets is a target for communication between information processing apparatuses. Here, the target does not operate at all unless there is a command from the host.

  An example of an interface protocol that can be transmitted only from one information processing apparatus is a USB protocol. Devices connected by this interface protocol are classified into a host (accessing side) and a target (accessed side), and the target responds to inquiries from the host side. Access is impossible as a mechanism. The host generally includes an information processing apparatus, and the target includes a keyboard, a mouse, a USB memory, and the like.

  However, there are the following problems in connecting two information processing apparatuses with an interface protocol that can be transmitted only from one information processing apparatus such as a USB protocol. Since the problem is one-way communication from one information processing device to the other information processing device, it is impossible to notify one information processing device that the other information processing device has received data. is there. In each embodiment, by solving this problem, secure communication using a general-purpose protocol is realized.

  In addition, the following problems exist as problems unique to the USB protocol. Since the USB connector of the information processing apparatus is not usually a type A connector, communication between type A connectors is enabled. In each embodiment, by solving this problem, secure communication using the USB protocol is realized.

  The specifications of the USB terminals / connector shape / pin arrangement are defined by the USB standard, the information processing apparatus (host) is a type A connector, and the target such as a USB memory is a type B connector. There is a need. On the other hand, the USB cable used in each embodiment uses a type A type USB cable at both ends of the connector in order to physically connect two information processing apparatuses. In addition, the USB pin arrangement No. 1 is a standard that can supply power from the host side to the target side as a power supply port. However, when two information processing apparatuses are connected, both ends are on the power supply side. Therefore, for the pin number 1, a cable in which terminals are not connected is used.

  In the two information processing apparatuses, the first information processing apparatus and the second information processing apparatus connected by the USB cable, the first information processing apparatus serves as a host and the second information processing apparatus serves as a target. In the following, data transmission is performed using the USB protocol.

  The second information processing apparatus that receives the data uses the first information as a part of the memory or the disk that can be seen from the first information processing apparatus on the other side as if the second information processing apparatus is a target. A shared storage unit is disclosed to other information processing apparatuses including the processing apparatus. The second information processing device stores a reception processing unit that reads or writes a data file stored in the shared storage unit, and a public driver that receives access to the shared storage unit from another information processing device using the USB protocol. A public driver storage unit. In addition, the first information processing apparatus that transmits data includes an access driver that stores data and an access driver for accessing the shared storage unit of the second information processing apparatus using the USB protocol. A driver storage unit.

  The public driver is software that sets an arbitrary storage area in the second information processing apparatus in the shared storage unit so that the external information processing apparatus can read and write by the USB protocol. In this case, when the second information processing apparatus is classified as a USB host and target, the second information processing apparatus behaves as the target side, and is configured so that the first information processing apparatus cannot transmit from the second information processing apparatus.

  The access driver is software that behaves as a host when classified as a USB host and target, and is a first information processing apparatus similar to a USB mass storage for a shared storage unit that is disclosed by a public driver using a USB protocol. Software that allows you to read from and write to.

  As a result, when viewed from the first information processing apparatus, the shared storage unit of the second information processing apparatus looks as if it is a USB memory inserted into the first information processing apparatus.

  With this configuration, the hardware mounted on the first information processing apparatus and the second information processing apparatus can be configured using only components constituting a general USB device. It is not necessary to incorporate hardware, and it is possible to realize the connection of two information processing apparatuses at low cost. In addition, since data is transmitted from the first information processing apparatus to the second information processing apparatus using a general-purpose protocol that can be transmitted only from the first information processing apparatus, the second information processing apparatus side It is possible to prevent the unauthorized communication data from entering the first information processing apparatus.

  In addition, since the contents of the shared storage unit of the second information processing apparatus can be seen from the first information processing apparatus, it is possible to check the safety of the shared storage unit (check for viruses etc.) before exchanging data. Therefore, more reliable communication is possible. In this way, the first information processing device is arranged on the side to be protected (for example, the control system side) and the second information processing device (for example, the OA system side) is arranged on the outside, and the above-described configuration is adopted. It is possible to prevent system tampering or information leakage from the control system.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described here does not limit the present invention at all, and merely illustrates one aspect of the present invention. In the description of the present invention, the USB is described as an example, but the shape and pin number of the USB connector include a Mini type and a Micro type in addition to the shape shown in FIG. The specifications may differ, but this is not a limitation. Also, the cable used in the present invention is not limited to the USB protocol as long as the host and target relations are established as in the USB and the interface protocol can be transmitted only from the first information processing apparatus. For example, the same protocol can be realized by using SCSI, S-ATA, or the like.

(First embodiment)
FIG. 1 is a schematic block diagram illustrating a configuration of a communication system 101 according to the first embodiment. As shown in FIG. 1, the communication system 101 in the first embodiment includes a first information processing apparatus 1 and an interface protocol that can be transmitted only from the first information processing apparatus 1 (here, USB protocol as an example). ) And a second information processing device 2 connected to the first information processing device 1 by a USB cable 3 according to FIG. Here, the information processing apparatus on the side to be protected is the first information processing apparatus 1, and the threatening side is the second information processing apparatus 2, while ensuring the safety of the first information processing apparatus 1. In order to realize data transmission from the information processing apparatus 1 to the second information processing apparatus 2, the following configuration is adopted.

  The first information processing apparatus 1 includes a transmission unit 4, an access driver storage unit 6, and an access driver execution unit 11.

The second information processing apparatus 2 includes a reception processing unit 5, a shared storage unit 8, a public driver storage unit 7, and a public driver execution unit 12.
The first information processing apparatus 1 and the second information processing apparatus 2 are not limited to the types and configurations of the information processing apparatuses as long as the above-described components are included.

First, each configuration of the first information processing apparatus 1 will be described.
The transmission unit 4 creates transmission data 9. Here, if the transmission data 9 is a data file determined in advance by the transmission unit 4 and the reception processing unit 5, the format and size of the file are not questioned.

  The transmission unit 4 can transmit transmission data 9 and completion data indicating that the transmission data 9 has been stored in the shared storage unit 8. Here, the completion data is data indicating that the transmission data 9 has been saved in the shared storage unit 8, and the transmission unit 4 notifies the second information processing apparatus 2 that the writing by the transmission unit 4 is completed. This file is created after the transmission data 9 is written. In the present embodiment, the completion data is the completion file 10 as an example.

  Here, the file format of the completion file 10 is not limited as long as it is determined in advance by the transmission unit 4 and the reception processing unit 5, but the file system of the transmission unit 4 and the reception processing unit 5 reads and writes data regarding the file size. It is preferably the minimum unit (block size) of data when performing.

  Thereby, whenever the reception processing unit 5 reads the completion file, the completion file has a complete configuration. For this reason, it is possible to avoid an abnormal operation by the reception processing unit 5 reading the completion file while the transmission unit 4 is writing the completion file.

  The access driver storage unit 6 stores an access driver for reading and writing to the shared storage unit 8 disclosed by the public driver using an interface protocol. Here, the access driver is software that behaves as a host side in accordance with the classification of USB host and target. The shared storage unit 8 disclosed by executing the public driver is configured to be readable and writable from the first information processing apparatus 1 by the USB protocol.

  The access driver execution unit 11 reads and executes the access driver from the access driver storage unit 6, thereby enabling the transmission unit 4 to read / write the shared storage unit 8 via the USB cable 3.

  For example, the transmission unit 4 accesses the shared storage unit 8 to check that there is no illegal file such as a virus file. For example, when the access driver execution unit 11 executes the access driver and becomes able to read and write to the shared storage unit 8 via the USB cable 3, the transmission unit 4 writes and reads a file to and from the shared storage unit 8. .

  In addition, when the access driver execution unit 11 executes the access driver and becomes able to read and write to the shared storage unit 8 via the USB cable 3, the transmission unit 4 determines whether completion data is stored in the shared storage unit 8. To determine. When the completion data (for example, the completion file 10) is not stored, the transmission unit 4 stores new transmission data in the shared storage unit 8 in response to a data transmission request on the first information processing apparatus 1, for example. After the new transmission data 9 is saved, the completion data (for example, the completion file 10) is saved in the shared storage unit 8. On the other hand, when the completion data is stored, the transmission unit 4 stands by.

  Subsequently, each configuration of the second information processing apparatus 2 will be described.

  The reception processing unit 5 monitors whether the transmission data 9 and the completion file 10 are stored in the shared storage unit 8. This monitoring may be performed periodically, or the public driver execution unit 12 may capture the event and notify the reception processing unit 5. In addition, when the transmission data 9 and the completion file 10 are stored, the reception processing unit 5 reads the transmission data 9 and performs data processing. Further, the reception processing unit 5 deletes the transmission data 9 and the completion file 10 after the data processing is completed.

  As described above, the reception processing unit 5 determines whether or not the completion data is stored in the shared storage unit 8. When the completion data is stored, the reception processing unit 5 reads the transmission data from the shared storage unit 8 and deletes the transmission data and the completion data from the shared storage unit 8 after the reading is completed.

The public driver storage unit 7 stores a public driver for making the shared storage unit 8 readable and writable from the first information processing apparatus 1 using an interface protocol.
Here, the public driver is software that allows an arbitrary storage area accessible from the second information processing apparatus 2 to be read / written from the first information processing apparatus 1 by the USB protocol using the shared storage unit 8. In this case, the public driver behaves as the target side according to the classification of USB host and target, and transmission from the second information processing apparatus 2 to the first information processing apparatus 1 is not possible. Configured as a thing.

  The public driver execution unit 12 reads the public driver from the public driver storage unit 12 and executes it.

  The shared storage unit 8 can store data. The shared storage unit 8 can be configured from an arbitrary storage area accessible from the second information processing apparatus 2, and is not limited to a built-in hard disk, but may be a memory or a connected external storage device.

  FIG. 2 is a table T1 showing a connection diagram between terminals of the USB cable 3 and an example of pin arrangement of the Type A USB connector. As shown in the connection diagram between the terminals of the USB cable 3 in FIG. 2, the USB cable 3 is different from a general USB cable in that the terminals at both ends adopt Type A (host side), and the pin number. 1 power terminals are not connected to each other. The D-terminals of pin number 2 are connected, the D + terminals of pin number 3 are connected, and the GND terminals of pin number 4 are connected.

FIG. 3 is a flowchart illustrating a schematic example of processing of the transmission unit 4 of the first information processing apparatus 1 and the reception processing unit 5 of the second information processing apparatus 2 in the first embodiment.
First, the processing of the transmission unit 4 of the first information processing apparatus 1 is as follows.

  (Step S101) First, the access driver execution unit 11 executes an access driver. As a result, the transmission / reception unit 4 can read / write the shared storage unit 8 via the USB cable 3.

  (Step S <b> 102) Next, the transmission unit 4 determines whether or not there is a completion file in the shared storage unit 8. When there is a completion file in the shared storage unit 8 (YES), the transmission unit 4 returns to step S101. On the other hand, when there is no completion file in the shared storage unit 8 (NO), the transmission unit 4 proceeds to step S103.

  (Step S103) The transmission unit 4 stores the transmission data in the shared storage unit 8.

  (Step S <b> 104) The transmission unit 4 stores the completed file 10 in the shared storage unit 8 after the transmission data 9 has been stored in step S <b> 103.

  Subsequently, the processing of the reception processing unit 5 of the second information processing apparatus 2 is as follows.

  (Step S201) First, the reception processing unit 5 periodically monitors whether the completion file 10 is created in the shared storage unit 8, for example. The reception processing unit 5 may detect the creation of the completion file 10 in the shared storage unit 8 by a notification from the public driver execution unit 12.

  (Step S202) Next, the reception processing unit 5 determines whether or not the completion file 10 exists in the shared storage unit 8. When the completion file 10 exists in the shared storage unit 8, that is, when the completion file 10 is created (YES), the reception processing unit 5 proceeds to step S203. On the other hand, when the completion file 10 does not exist in the shared storage unit 8, that is, when the completion file 10 is not created (NO), the reception processing unit 5 returns to Step S201.

  (Step S <b> 203) The reception processing unit 5 reads the transmission data 9 and executes a process according to the content of the transmission data 9.

  (Step S204) Next, the reception processing unit 5 deletes the transmission data 9 after the reading of the transmission data 9 is completed in Step S203.

  (Step S205) Next, the reception processing unit 5 deletes the completion file 10.

  As a result, the first information processing apparatus 1 can continuously transmit data to the second information processing apparatus 2 using an interface protocol that can be transmitted only from the first information processing apparatus 1. it can.

  As described above, the communication system 101 according to the first embodiment is connected to the first information processing apparatus 1 by the cable according to the first information processing apparatus 1 and the interface protocol capable of transmitting only from the first information processing apparatus 1. The second information processing apparatus 2 is provided.

  The second information processing apparatus 2 stores a shared storage unit 8 capable of storing data, and a public driver for making the shared storage unit 8 readable and writable from the first information processing apparatus 1 using an interface protocol. A public driver storage unit 7, a public driver execution unit 12 that reads and executes a public driver from the public driver storage unit 7, and a reception processing unit 5 that reads data stored in the shared storage unit 8.

  The first information processing apparatus 1 includes an access driver storage unit 6 in which an access driver for accessing the shared storage unit 8 disclosed by the public driver using an interface protocol is stored, and the access driver storage unit 6 from the access driver storage unit 6. By reading and executing the access driver, the access driver execution unit 11 that enables the transmission unit 4 to read and write the shared storage unit 8 via the cable, and the transmission data and the transmission data are stored in the shared storage unit 8 A transmission unit 4 capable of transmitting completion data indicating the completion.

  The transmission unit 4 determines whether or not completion data is stored in the shared storage unit 8 when the shared storage unit 8 becomes readable and writable. If the completion data is not stored, the transmission unit 4 stores new transmission data in a shared manner. The data is stored in the unit 8, and after the new transmission data is stored, the completion data is stored in the shared storage unit 8. The reception processing unit 5 determines whether or not the completion data is stored in the shared storage unit 8. When the completion data is stored, the reception processing unit 5 reads the transmission data from the shared storage unit 8 and completes the transmission data and the completion after the reading is completed. Data is deleted from the shared storage unit 8.

  Thus, it is not necessary to prepare dedicated hardware on the device side, and communication can be performed by preparing only the components constituting the USB device and a simple cable and connecting the two information processing devices. Further, since the communication always requires transmission from the host side, that is, the first information processing device 1 at the protocol level, the second information processing device 2 enters the first information processing device 1, It is possible to prevent unauthorized IP communication from flowing. Furthermore, since the safety of the shared storage unit can be checked (check for viruses, etc.) before data is transmitted, more reliable communication is possible.

<Modification of First Embodiment>
As shown in FIG. 4, there may be a configuration in which there are a plurality of first information processing apparatuses 1 and the second information processing apparatus 2 receives transmission data from each first information processing apparatus 1.
FIG. 4 is a schematic block diagram illustrating a configuration of the communication system 101a according to the modification of the first embodiment. Elements common to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The configuration of the communication system 101a in the modification of the first embodiment is the second configuration in which a first information processing device 1-2 is further added to the configuration of the communication system 101 in the modification of the first embodiment. The information processing apparatus 2 is changed to the second information processing apparatus 2a. The added first information processing apparatus 1-2 is connected to the second information processing apparatus 2a via the USB cable 3-2. The second information processing apparatus 2a further includes a reception processing unit 5-2 and a shared storage unit 8-2 as compared with the second information processing apparatus 2.

The transmission unit 4 of the first information processing device 1-2 has the same function as the transmission unit 4 of the first information processing device 1, but the second storage unit 8-2 of the second information processing device 2a has a second function. 2 The difference is that the transmission data 9-2 and the second completion file 10-2 are stored.
The reception processing unit 5-2 has the same function as the reception processing unit 5, except that the monitoring target is the shared storage unit 8-2.

  As described above, according to the communication system 101a in the modification of the first embodiment, since the transmission from the first information processing apparatus 1 is necessary, the second information processing apparatus 2 to the first information processing apparatus 1 and It becomes possible to prevent the intrusion into the first information processing apparatus 1-2 and the flow of unauthorized IP communication.

(Second Embodiment)
Next, the second embodiment will be described. FIG. 5 is a schematic block diagram illustrating a configuration of the communication system 102 according to the second embodiment. Elements common to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. The configuration of the communication system 102 according to the second embodiment is changed from the configuration of the communication system 101 according to the first embodiment to the transmission unit 4 being changed to the transmission unit 4b and the reception processing unit 5 being changed to the reception processing unit 5b. It has been done. Accordingly, the first information processing apparatus 1 is changed to the first information processing apparatus 1b, and the second information processing apparatus 2 is changed to the second information processing apparatus 2b.

In addition to having the same function as the reception processing unit 5 of the first embodiment, the reception processing unit 5 b creates a result file 11 in the shared storage unit 8. The result file 11 is a file including a status (STS) indicating whether or not the reading by the reception processing unit 5b is successful.
The reception processing unit 5 can save the result file 11 by switching the status (STS) in the result file 11 depending on the result of reading the transmission data 9 between success (OK) and error (ERR). it can.

In addition to having the same function as that of the transmission unit 4 of the first embodiment, the transmission unit 4b has a function of reading the result file 11, and transmits the next transmission data according to the read result. It is determined whether the previous transmission data is transmitted.
The transmission unit 4 refers to the status (STS) in the file 11 as a result, and when the status (STS) is an error (ERR), saves the same file as the previous data in the shared storage unit 8 as the transmission data 9. On the other hand, when the status (STS) is successful (OK), the transmission unit 4 stores the next file as transmission data 9 in the shared storage unit 8.

FIG. 6 is a flowchart illustrating a schematic example of processing of the transmission unit 4b of the first information processing device 1b and the reception processing unit 5b of the second information processing device 2b in the second embodiment.
First, the processing of the transmission unit 4b of the second information processing apparatus 1b is as follows.

  (Step S301) First, the access driver execution unit 11 executes an access driver. Thereby, reading / writing of the shared storage part 8 via the USB cable 3 by the transmission part 4b is attained.

  (Step S302) Next, the transmission unit 4b determines whether or not the result file 11 exists in the shared storage unit 8. When the result file 11 is present in the shared storage unit 8 (YES), the transmission unit 4b proceeds to step S303. On the other hand, when the result file 11 does not exist in the shared storage unit 8 (NO), the transmission unit 4b returns to Step S301. Read the result file.

  (Step S303) When it is determined in step S302 that the result file 11 exists in the shared storage unit 8, the transmission unit 4b reads the result file 11.

  (Step S304) Next, it is determined whether the status (STS) is an error (ERR). When the status (STS) is an error (ERR) (YES), the transmission unit 4b proceeds to step S305. On the other hand, if the status (STS) is not an error (ERR) (NO), that is, if the status (STS) is successful (OK), the transmission unit 4b proceeds to step S306.

  (Step S305) When the status (STS) is determined to be error (ERR) in step S304, the previous transmission data is stored in the shared storage unit 8.

  (Step S306) If the status (STS) is determined to be error (ERR) in step S304, the next transmission data is stored in the shared storage unit 8.

  (Step S307) The transmission unit 4b stores the completion file in the shared storage unit 8.

  Subsequently, the processing of the reception processing unit 5b of the second information processing apparatus 2 is as follows.

  (Step S401) First, the reception processing unit 5b periodically monitors whether the completion file 10 is created in the shared storage unit 8, for example. Note that the reception processing unit 5 b may detect the creation of the completion file 10 in the shared storage unit 8 by a notification from the public driver execution unit 12.

  (Step S402) Next, the reception processing unit 5b determines whether or not the completion file 10 exists in the shared storage unit 8. When the completion file 10 exists in the shared storage unit 8, that is, when the completion file 10 is created (YES), the reception processing unit 5b proceeds to step S403. On the other hand, when there is no completion file 10 in the shared storage unit 8, that is, when the completion file 10 has not been created (NO), the reception processing unit 5b returns to Step S401.

  (Step S403) The reception processing unit 5b reads the transmission data in the shared storage unit 8, and performs processing according to the content of the transmission data.

  (Step S404) Next, the reception processing unit 5b determines whether or not the transmission data has been successfully read. If the transmission data has been successfully read (YES), the reception processing unit 5b sets the status (STS) to success (OK) and proceeds to step S405. On the other hand, if the transmission data has not been successfully read (NO), the reception processing unit 5b sets the status (STS) to failure (NO) and proceeds to step S405.

  (Step S405) Next, the reception processing unit 5b deletes the transmission data stored in the shared storage unit 8.

  (Step S406) Next, the reception processing unit 5b deletes the completion file stored in the shared storage unit 8.

  (Step S407) Next, the status (STS) is described in the result file, and the result file in which the status (STS) is described is stored in the shared storage unit 8. If the result file already exists, the status (STS) in the result file is updated.

  In the present embodiment, as an example, the reception processing unit 5b stores the result file including the status. However, the present invention is not limited to the mode of storing in such a file format. The reception processing unit 5b may store status data indicating success or failure of reading of transmission data by the reception processing unit 5b. An example of the status data is a result file including the status.

  As described above, in the second embodiment, the reception processing unit 5b shares the status data indicating the success or failure of reading the transmission data by the reception processing unit (in this embodiment, the result file including the status) as a shared storage unit. 8 is stored. The transmission unit 4b reads the status data from the shared storage unit 8, and saves the previous transmission data in the shared storage unit 8 or the next transmission data in the shared storage unit 8 according to the read status data. Do one.

  Thus, data is retransmitted to the first information processing apparatus 1 according to the processing result of the transmission data 9 received on the second information processing apparatus 2 side, using the USB protocol that can communicate only in one direction. Will be able to request. For this reason, in addition to the effects of the first embodiment, data reception omission can be prevented.

(Third embodiment)
Subsequently, a third embodiment will be described. FIG. 7 is a schematic block diagram illustrating the configuration of the communication system 103 according to the third embodiment. Elements common to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. The configuration of the communication system 103 in the third embodiment is changed from the configuration of the communication system 101 in the first embodiment to the transmission unit 4 being changed to the transmission unit 4c and the reception processing unit 5 being changed to the reception processing unit 5c. It has been done. Accordingly, the first information processing apparatus 1 is changed to the first information processing apparatus 1c, and the second information processing apparatus 2 is changed to the second information processing apparatus 2c.

  In addition to having the same function as the transmission unit 4 of the first embodiment, the transmission unit 4c can store a plurality of transmission data 9 and completion files 10 with different file names. The transmission unit 4 c is different in that the file name of the corresponding transmission data 9 is included in the completion file 10. Thus, the transmission unit 4 can store the next transmission data 9 and the completion file 10 with different file names without confirming that the completion file has been deleted.

  In addition to having the same function as the reception processing unit 5c of the first embodiment, the reception processing unit 5c reads the completion file 10 in order of the oldest time stamp, and reads the transmission data 9 of the file name in the completion file 10. . After completing the reading of the transmission data 9, the reception processing unit 5c deletes the read transmission data 9 and the read completion file 10.

FIG. 8 is a flowchart illustrating a schematic example of processing of the transmission unit 4c of the first information processing device 1c and the reception processing unit 5c of the second information processing device 2c in the third embodiment.
First, the process of the transmission unit 4c of the third information processing apparatus 1c is as follows.

  (Step S501) First, the transmission unit 4c stores the next transmission data 9 with a different file name in the shared storage unit 8 without confirming that the completion file has been deleted. As a result, the transmission file including the transmission data 9 is stored in the shared storage unit 8.

  (Step S502) Next, the transmitting unit 4c saves the next completed file 10 with a different file name in the shared storage unit 8 without confirming that the completed file has been deleted. At this time, the transmission unit 4 c describes the file name of the corresponding transmission data 9 in the completion file 10 and stores the next completion file 10.

  Next, the processing of the reception processing unit 5c of the third information processing apparatus 1c is as follows.

  (Step S601) First, the reception processing unit 5c periodically monitors, for example, whether or not the completion file 10 is created in the shared storage unit 8. The reception processing unit 5 may detect the creation of the completion file 10 in the shared storage unit 8 by a notification from the public driver execution unit 12.

  (Step S602) Next, the reception processing unit 5c determines whether or not the completion file 10 exists in the shared storage unit 8. When the completion file 10 exists in the shared storage unit 8, that is, when the completion file 10 is created (YES), the reception processing unit 5c proceeds to step S603. On the other hand, when the completion file 10 does not exist in the shared storage unit 8, that is, when the completion file 10 has not been created (NO), the reception processing unit 5c returns to step S601.

  (Step S603) Next, the reception processing unit 5c reads the completed file 10 with the oldest time stamp from the shared storage unit 8, and reads the file name described in the completed file 10.

  (Step S604) Next, the reception processing unit 5c reads the transmission file having the file name described in the completion file 10 from the shared storage unit 8, and performs processing according to the content of the transmission file.

  (Step S605) Next, the reception processing unit 5c deletes the read transmission file.

  (Step S606) Next, the reception processing unit 5c deletes the read completion file 10.

  As described above, in the third embodiment, the completion data is a completion file indicating completion of transmission of transmission data. The transmission unit 4c stores the transmission data in the shared storage unit 8 with a different file name for each transmission data, and stores the completion file including the file name of the corresponding transmission data in the shared storage unit 8 with a different file name. To do. The reception processing unit 5c reads the completion file in order from the oldest time stamp, and reads the transmission data of the file name in the completion file.

  Accordingly, the transmission unit 4c can save the transmission data 9 and the completion file 10 one after another in the shared storage unit 8 without confirming the result read by the reception processing unit 5c. For this reason, in addition to the effects of the first embodiment, data can be transmitted continuously, and the communication throughput can be improved.

  The transmission unit 4c may include a code number in the completion file 10. In that case, the reception processing unit 5c may read the transmission data 9 of the file name of the code number. For example, when the code number is “1”, the reception processing unit 5 c may read the transmission data 9 having the file name “1”.

(Fourth embodiment)
Subsequently, a fourth embodiment will be described. FIG. 9 is a schematic block diagram illustrating the configuration of the communication system 104 according to the fourth embodiment. Elements common to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. The configuration of the communication system 104 in the fourth embodiment is different from the configuration of the communication system 101 in the first embodiment in that the first information processing device 1 is changed to the first information processing device 1d. In the information processing apparatus 1d, the transmission unit 4 is changed to the transmission unit 4d, and the buffer unit 13 is added.

  In addition to having the same function as the transmission unit 4 of the first embodiment, the transmission unit 4d temporarily stores the data that could not be stored as buffer data 14 when the transmission data 9 or the completion file 10 could not be stored. Save in the buffer unit 13. Thereafter, when the transmission unit 4d becomes capable of transmission, the buffer data 14 is read from the buffer unit 13 in the order of the oldest time stamp, and the read buffer data 14 is stored in the shared storage unit 8 in the first embodiment. Different from the transmission unit 4.

  As described above, in the fourth embodiment, the first information processing apparatus 1d includes the buffer unit 13 that temporarily stores data. When the transmission unit 4d cannot store the transmission data or the completion data in the shared storage unit 8, the transmission unit 4d temporarily stores the transmission data or the completion data as buffer data in the buffer unit 13, and when the transmission unit 4d can be stored in the shared storage unit 8, the buffer unit 13 The buffer data is read out in ascending order of time stamp, and the read buffer data is stored in the shared storage unit 8.

  As a result, when the second information processing apparatus 2 is stopped for some reason or when the storage area of the shared storage unit 8 is insufficient, the storage cannot be performed in the shared storage unit 8 The transmission unit 4d of the first information processing apparatus 1 stores the buffer data 14 in the buffer unit 13 and stores it in the shared storage unit 8 when transmission is possible. For this reason, in addition to the effect of 1st Embodiment, the transmission omission of the transmission data 9 can be prevented.

(Fifth embodiment)
Subsequently, a fifth embodiment will be described. FIG. 10 is a schematic block diagram showing the configuration of the communication system 105 in the fifth embodiment. Elements common to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. The configuration of the communication system 105 in the fifth embodiment is the same as the configuration of the communication system 101 in the first embodiment except for the second information processing connected to the first information processing apparatus 1 by the USB cable 3-2. The apparatus 2-2 is added, and the transmission unit 4 is changed to the transmission unit 4e. Accordingly, the first information processing apparatus 1 is changed to the first information processing apparatus 1e.

  Here, the second information processing apparatus 2-2 includes a reception processing unit 5-2, a shared storage unit 8-2, a public driver storage unit 7-2, and a public driver execution unit 12-2. Since these constituent elements have the same functions as the corresponding constituent elements of the second information processing apparatus 2, detailed description thereof will be omitted.

  In addition to having the functions described in the first embodiment, the access driver stored in the access driver storage unit 6 has a plurality of shared storage units 8 and 8-2 implemented in a plurality of information processing apparatuses. The first information processing apparatus 1 can be read / written by the USB protocol.

Further, in addition to having the function described in the first embodiment, the transmission unit 4e stores the same transmission data 9 and 9-2 for a plurality of storage destinations. -2 can be stored. Further, the transmission unit 4e transmits the next data after confirming that all of the saved completion files 10 and 10-2 have been deleted.
In addition, when the transmission unit 4e cannot access the shared storage unit 8 of the second information processing apparatus 2 or 2-2, the transmission unit 4e determines the accessible one and stores the accessible shared storage unit 8 in the shared storage unit 8. The transmission data 9, 9-2 and the completion files 10, 10-2 may be saved.

Subsequently, the flow of processing of the communication system 105 in the fifth embodiment will be described below.
The transmission unit 4e stores the transmission data 9 and the completion file 10 in the shared storage unit 8 of the second information processing device 2, and stores the transmission data 9 in the shared storage unit 8-2 of the second information processing device 2-2. The same transmission data 9-2 and the completion file 10-2 are saved.

  The reception processing unit 5 reads the transmission data 9 file stored in the shared storage unit 8 and deletes the transmission data 9 and the completed file 10 stored in the shared storage unit 8 after the reading is completed. Similarly, the reception processing unit 5-2 reads the transmission data 9-2 file stored in the shared storage unit 8-2, and after the reading is completed, the transmission data 9 stored in the shared storage unit 8-2. -2 and the completion file 10-2 are deleted.

  The transmission unit 4e confirms that the completed files 10 and 10-2 of both the shared storage unit 8 and the shared storage unit 8-2 are deleted, and then transmits the next transmission file to the shared storage unit 8 and the shared storage unit 8. -2.

  As described above, in the fifth embodiment, there are a plurality of second information processing apparatuses, and when the access driver execution unit 11 executes the access driver, the transmission unit 4e has the plurality of second information processing apparatuses 2, 2- The shared storage units 8 and 8-2 included in 2 can be read and written. The transmission unit 4e checks whether or not all the completion data stored in the plurality of shared storage units 8 and 8-2 has been deleted. If all the deletion data is deleted, the transmission unit 4e transmits the next transmission data and completion data to the plurality of shared storage units. Save to 8.

  Accordingly, the same transmission data 9 and 9-2 can be transmitted from the first information processing apparatus 1 to the plurality of information processing apparatuses 2 and 2-2 connected by the USB cables 3 and 3-2. Become. For this reason, in addition to the effect of 1st Embodiment, the same data can be transmitted to two 2nd information processing apparatuses 2 and 2-2 from which processing differs. In addition, when the two second information processing devices 2 and 2-2 execute the same process, the second information processing device 2 and the second information processing device 2-2 on the receiving side multiplex them. Even when one information processing apparatus stops, the other information processing apparatus can continue the same processing.

(Sixth embodiment)
Subsequently, a sixth embodiment will be described. FIG. 11 is a schematic block diagram illustrating the configuration of the communication system 106 according to the sixth embodiment. Elements common to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. In the configuration of the communication system 106 according to the sixth embodiment, the first information processing apparatus 1 is changed to the first information processing apparatus 1f as compared with the communication system 101 according to the first embodiment, and the second information processing is performed. The apparatus 2 is changed to the second information processing apparatus 2f.

The first information processing apparatus 1f is obtained by adding a second reception processing unit 23 as compared to the first information processing apparatus 1 of the first embodiment.
The second information processing device 2f is obtained by adding a second transmission unit 20 as compared with the second information processing device 2 of the first embodiment.

The second transmission unit 20 has the same function as the transmission unit 4 of the first embodiment, but the storage destination of the second transmission data 21 and the second completion file 22 is the local shared storage unit 8. There are some differences.
The second reception processing unit 23 has the same function as that of the reception processing unit 5 of the first embodiment, but the reading destination of the second transmission data 21 and the second completion file 22 is the second information. The difference is that it is a shared storage unit 8 in the processing device 2.

The second transmission unit 20 creates the second transmission data 21 and stores the created second transmission data 21 in the shared storage unit 8. The second transmission unit 20 stores the second completion file 22 after the storage of the second transmission data 21 is completed.
The second reception processing unit 23 periodically monitors the creation of the second completion file 22 in the shared storage unit 8. When the second completion file 22 has been created, the second reception processing unit 23 reads the second transmission data 21 and performs a process according to the content of the second transmission data 21.

  As described above, in the sixth embodiment, the second information processing device 2f can store the second transmission data 21 and the second completion data 22 in the shared storage unit 8 included in the second information processing device 2f. The second transmission unit 20 is further provided. Then, the first information processing apparatus 1 f reads the second transmission data 21 and the second completion data 22 stored in the second transmission unit 20 from the shared storage unit 8 via the USB cable 3. A reception processing unit 23 is further provided.

  Thereby, in addition to the effects of the first embodiment, not only the data transmission from the first information processing apparatus 1 to the second information processing apparatus 2 but also the second information processing apparatus 2 to the first information processing apparatus. It is possible to transmit data to 1, and bi-directional communication can be realized.

(Seventh embodiment)
Subsequently, a seventh embodiment will be described. FIG. 12 is a schematic block diagram showing the configuration of the communication system 107 in the seventh embodiment. Elements common to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. The configuration of the communication system 107 in the seventh embodiment is different from the configuration of the communication system 101 in the first embodiment in that the first information processing device 1 is changed to the first information processing device 1g. The apparatus 2 is changed to the second information processing apparatus 2g.

  The first information processing apparatus 1g is connected to the first network 24 as compared with the first information processing apparatus 1 of the first embodiment, the transmission unit 4 is changed to the transmission unit 4g, and the reception conversion unit 26 is added. Compared to the first information processing apparatus 1 of the first embodiment, the second information processing apparatus 2g is connected to the second network 25, the reception processing unit 5 is changed to the reception processing unit 5g, and further converted. A transmission unit 27 is added.

  The reception conversion unit 26 receives IP protocol data transmitted from any information processing apparatus in the first network 24 according to the TCP / IP protocol. The reception conversion unit 26 converts the received IP protocol data into a file, and outputs the file obtained by the conversion to the transmission unit 4.

  In addition to having the same function as the transmission unit 4 of the first embodiment, the transmission unit 4g stores the file output from the reception conversion unit 26 in the shared storage unit 8 as transmission data.

  The reception processing unit 5g has the same function as that of the reception processing unit 5g of the first embodiment, and transmits the content of the read transmission data 9 to the conversion transmission unit 27.

  The conversion transmission unit 27 converts the file output from the reception processing unit 5 into data of an IP protocol including the IP address of the second information processing apparatus as a transmission source, and converts the data obtained by the conversion to the second network 25 according to the TCP / IP protocol.

  As a result, the IP packet transmitted from the arbitrary information processing apparatus of the first network 24 to the reception conversion unit 26 is transmitted to the conversion transmission unit 27 through the transmission unit 4 and the reception processing unit 5, and is transmitted from the second network 25. It is transmitted to any information processing apparatus.

  As described above, in the seventh embodiment, the first information processing apparatus 1g receives a packet transmitted by IP communication from an arbitrary information processing apparatus on the first network to which the first information processing apparatus 1g is connected. It further includes a reception conversion unit 26 that receives and converts the received packet into a predetermined data format and outputs the converted data to the transmission unit 4g. In the second information processing apparatus 2g, the reception processing unit 5g reads the transmission data stored in the shared storage unit 8, and outputs the read transmission data. The second information processing device 2g converts the transmission data output from the reception processing unit 5g into a packet, and converts the converted packet into arbitrary information on the second network 25 to which the second information processing device 2g is connected. A conversion transmission unit 27 is further provided for transmitting to the processing device by IP communication.

  As a result, in addition to the effects of the first embodiment, an IP packet is transmitted from an arbitrary information processing apparatus existing on the first network 24 to an arbitrary information processing apparatus existing on the second network 25. It becomes possible to do.

  Note that a program for executing each process of the first information processing apparatus or the second information processing apparatus of each embodiment is recorded on a computer-readable recording medium, and the program recorded on the recording medium is recorded on the computer. The above-described various processes related to the first information processing apparatus or the second information processing apparatus of each embodiment may be performed by being read by the system and executed by the processor.

  Here, the “computer system” may include an OS and hardware such as peripheral devices. Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used. The “computer-readable recording medium” means a flexible disk, a magneto-optical disk, a ROM, a writable nonvolatile memory such as a flash memory, a portable medium such as a CD-ROM, a hard disk built in a computer system, etc. This is a storage device.

  Further, the “computer-readable recording medium” means a volatile memory (for example, DRAM (Dynamic) in a computer system which becomes a server or a client when a program is transmitted through a network such as the Internet or a communication line such as a telephone line. Random Access Memory)) that holds a program for a certain period of time is also included. The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

  As described above, the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

101, 101a, 102, 103, 104, 105, 106, 107 Communication system 1, 1-2, 1b, 1c, 1d, 1e, 1f, 1g First information processing device 2, 2a, 2b, 2c, 2f, 2g, 2-2 Second information processing device 4, 4b, 4c, 4d, 4e, 4g Transmission unit 6 Access driver storage unit 11 Access driver execution unit 5, 5b, 5c, 5g Reception processing unit 8 Shared storage unit 7 Release Driver storage unit 12 Public driver execution unit 20 Second transmission unit 23 Second reception processing unit 24 First network 25 Second network 26 Reception conversion unit

Claims (10)

A communication system comprising: a first information processing apparatus; and a second information processing apparatus connected to the first information processing apparatus with a cable conforming to an interface protocol that can be transmitted only from the first information processing apparatus. Because
The second information processing apparatus
A shared storage unit capable of storing data;
A public driver storage unit in which a public driver for making the shared storage unit readable and writable from the first information processing apparatus using the interface protocol is stored;
A public driver execution unit that reads and executes the public driver from the public driver storage unit;
A reception processing unit that reads data stored in the shared storage unit;
With
The first information processing apparatus includes:
An access driver storage unit storing an access driver for accessing the shared storage unit disclosed by the public driver using the interface protocol;
A transmission unit capable of transmitting transmission data and completion data indicating completion of storage of the transmission data in the shared storage unit;
An access driver execution unit that enables reading and writing of the shared storage unit via the cable by the transmission unit by reading and executing the access driver from the access driver storage unit;
With
The transmission unit determines whether or not the completion data is stored in the shared storage unit. If the completion data is not stored, the transmission unit stores new transmission data in the shared storage unit and performs the new transmission. After the data is saved, the completion data is saved in the shared storage unit,
The reception processing unit determines whether the completion data is stored in the shared storage unit. When the completion data is stored, the transmission processing unit reads the transmission data from the shared storage unit, and after the reading is completed, the transmission data A communication system for deleting data and the completion data from the shared storage unit. The reception processing unit stores status data indicating success or failure of reading transmission data by the reception processing unit in the shared storage unit,
The transmission unit reads the status data from the shared storage unit, and saves the previous transmission data in the shared storage unit or the next transmission data to the shared storage unit according to the read status data The communication system according to claim 1, wherein one of storage is executed. The completion data is a completion file indicating completion of transmission of transmission data,
The transmission unit stores the transmission data in the shared storage unit with a different file name for each transmission data, and stores a completion file including the file name of the corresponding transmission data in the shared storage unit with a different file name And
The communication system according to claim 1, wherein the reception processing unit reads the completion file in order of oldest time stamp and reads transmission data having a file name in the completion file. The first information processing apparatus includes a buffer unit for temporarily storing data,
If the transmission data or the completion data cannot be stored in the shared storage unit, the transmission unit temporarily stores the data that could not be stored as buffer data in the buffer unit and can be stored in the shared storage unit. 2. The communication system according to claim 1, wherein the buffer data is read from the buffer unit in order of oldest time stamp, and the read buffer data is stored in the shared storage unit. There are a plurality of the second information processing apparatuses,
When the access driver execution unit executes the access driver, the transmission unit can read and write to the shared storage unit included in a plurality of second information processing devices,
The transmission unit confirms whether or not all the completion data stored in the plurality of shared storage units has been deleted, and when all are deleted, stores the next transmission data and completion data in the plurality of shared storage units The communication system according to claim 1. The second information processing apparatus
A second transmission unit capable of storing second transmission data and second completion data in the shared storage unit included in the second information processing apparatus;
The first information processing apparatus includes:
The communication according to claim 1, further comprising: a second reception processing unit that reads out the second transmission data and the second completion data stored by the second transmission unit from the shared storage unit via the cable. system. The first information processing apparatus includes:
Receives a packet transmitted by IP communication from an arbitrary information processing apparatus on the first network to which the first information processing apparatus is connected, converts the received packet into a predetermined data format, and converts the converted data Further comprising a reception conversion unit for outputting to the transmission unit,
The second information processing apparatus
The reception processing unit reads transmission data stored in the shared storage unit, outputs the read transmission data,
A conversion transmission unit that converts transmission data output from the reception processing unit into a packet, and transmits the converted packet to an arbitrary information processing device on the second network to which the second information processing device is connected by IP communication. The communication system according to claim 1. An information processing apparatus connected by a cable to another information processing apparatus including a shared storage unit capable of storing data ,
An access driver for accessing the shared storage unit disclosed by a public driver for making the shared storage unit readable and writable from the information processing device using an interface protocol that can be transmitted only from the information processing device. A stored access driver storage unit;
A transmitter capable of transmitting a completion data indicating that the transmission data and the transmission data has been completed stored in the shared storage unit,
By reading and executing the access driver stored in the access driver storage unit, and the access driver execution unit that can store data in the shared storage unit through said cable from said transmitting section,
With
It said cable is a cable according to the interface protocol,
The transmission unit determines whether or not the completion data is stored in the shared storage unit. If the completion data is not stored, the transmission unit stores new transmission data and new completion data in the shared storage unit. Information processing device. An information processing apparatus connected to the other information processing apparatus with a cable conforming to an interface protocol that can be transmitted only from the other information processing apparatus,
A shared storage unit capable of storing data;
A public driver storage unit in which a public driver for making the shared storage unit accessible from the other information processing apparatus using the interface protocol is stored;
A driver execution unit that reads and executes the public driver from the public driver storage unit;
A reception processing unit that reads data stored in the shared storage unit;
With
The reception processing unit determines whether or not completion data indicating transmission completion of transmission data is stored in the shared storage unit, and when the completion data is stored, reads the transmission data from the shared storage unit, An information processing apparatus that deletes the transmission data and the completion data from the shared storage unit after the reading is completed. A first information processing apparatus, and a first second information processing apparatus originating from the information processing apparatus only is connected to the first information processing apparatus by a cable according to the interface protocol as possible, the first The information processing apparatus 2 stores a public storage in which a shared storage unit capable of storing data and a public driver for making the shared storage unit accessible from the first information processing apparatus using the interface protocol are stored. a driver storage unit, the first information processing apparatus, an access driver storage unit access driver for accessing said shared storage unit that is published by the public driver using said interface protocol is stored a transmission section capable of transmitting a completion data indicating that it has completed saving the transmission data and the transmission data in the shared storage unit A communication method comprising Ru communication system performs,
A step in which the driver execution unit reads and executes the public driver from the public driver storage unit;
The access driver execution unit reads and executes the access driver from the access driver storage unit, thereby enabling the transmission unit to read and write the shared storage unit via the cable;
The transmitting unit, the completion data is determined whether or not stored in the shared storage unit, if the complete data is not stored, stores the new and new transmission data complete data in the shared storage unit Process,
The reception processing unit determines whether the completion data is stored in the shared storage unit, and when the completion data is stored, reads the transmission data and the completion data from the shared storage unit, and after the reading is completed, Deleting transmission data and the completion data from the shared storage unit;
A communication method comprising:

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