JP2007329563A - Communicating system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for quickly starting communication processing on the occurrence of a request in a non always-on connection line network and completing the processing without causing a communication error. <P>SOLUTION: When a communication terminal 10 transmits a UDP packet to an apparatus 50 (S101), a relaying apparatus 30 transmits a control signal to the apparatus 50 (S102). The apparatus 50 makes dialup connection to establish a PPP session with the relaying apparatus 30 (S104, S105) and establish a TCP connection (S106). The communication terminal 10 designates a batch mode and transmits an inspection instruction file to the apparatus 50 (S107, S108). The apparatus 50 disconnects the TCP connection (S109), executes inspection according to the inspection instruction file, and generates an inspection result file. When the apparatus 50 makes dialup connection and establishes the PPP session and the TCP connection (S114 to S116), the apparatus 50 returns the inspection result file to the communication terminal 10 (S117). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a communication processing technique in a communication system including an emergency connection terminal.

  There are a permanent connection and an emergency connection as a form in which the terminal is connected to the network. When the terminal is always connected to the network, a fixed IP address can be assigned to the terminal. Therefore, in a communication system including a terminal that is always connected, it is possible to establish communication with the terminal at an arbitrary timing and perform communication.

  On the other hand, when the terminal is connected to the network in an emergency, since the IP address of the terminal is not fixed, a device is required to communicate with the terminal. For example, when a terminal is connected to the network by dialing up, the IP address is assigned to the terminal from the dial-up server every time dial-up connection is performed. Therefore, a TCP connection cannot be established at an arbitrary timing for this terminal.

  Patent Document 1 proposes a technique for quickly performing data communication even when a terminal whose IP address is not fixed is included in the information system. Specifically, in Patent Document 1, the IP adapter 40 is not always given a fixed IP address. The IP adapter 40 periodically transmits a UDP packet to the server 42 and periodically notifies the IP address of the own device. When a control request signal is generated from the cellular phone 44 to the server 42, the server 42 knows the IP address of the IP adapter 40, and can immediately connect to the IP adapter 40. Thereby, when a processing trigger is generated from the mobile phone 44, it is possible to quickly perform data communication via the server 42 and the IP adapter 40.

Japanese Patent Laid-Open No. 2005-210575

  As described above, when a terminal performing emergency connection is included in the communication system, it is necessary to devise a connection to the terminal. According to Patent Document 1, the receiving terminal (IP adapter 40) regularly sends a UDP packet to the server, so that the IP address of its own device is always notified.

  However, there is another problem when using an emergency connection network. In an emergency connection line network, it may be difficult for a specific terminal to maintain a connection state for a long time. For example, in order to provide a service to many users, there is a case where a connection that does not generate traffic for a predetermined time is disconnected. Some dial-up routers disconnect the connection with a line when no packet is transmitted for a predetermined time.

  As described above, in a communication system including an emergency-connected terminal, first, it is necessary to devise a method for quickly communicating, and further, until the transmission / reception of necessary information is completed, the connection state is Ingenuity to maintain is necessary. This is because if a communication error or the like occurs in the middle of data transmission / reception, the processing becomes complicated, for example, recovery processing is required.

  Therefore, in view of the above problems, the present invention provides a technique for quickly and efficiently starting communication processing when a communication request occurs and completing communication normally in a communication system including an emergency connection terminal. The task is to do.

  In order to solve the above-described problem, the invention according to claim 1 is that the first communication device and the relay device are always connected, and the relay device and the second communication device are established by a connection request from the second communication device. The second communication device transmits a TCP connection request to the first communication device after establishing a communication network by making a connection request to the relay device. The first communication device establishes a TCP connection with the second communication device in response to a TCP connection request from the second communication device, and then designates a return mode and sends a transmission file to the second communication device. Means for transmitting to the device, and when the first mode is designated as the reply mode, the second communication device maintains the TCP connection used when the transmission file is received while maintaining the reply file. If the second mode is designated, the communication network with the relay device is disconnected, and after establishing the communication network with the relay device again, a new TCP A connection is established and a reply file is transmitted.

  According to a second aspect of the present invention, in the communication system according to the first aspect, the second communication device disconnects the communication network with the relay device, and then communicates again when the reply file is ready for transmission. It is characterized by establishing a network.

  According to a third aspect of the present invention, in the communication system according to the first aspect, the second communication device performs a reply file reply process even when the first mode is designated as a reply mode. If it is determined that the required time corresponds to a predetermined condition, the communication network with the relay device is disconnected, the communication network with the relay device is established again, and then a new TCP connection is established. And sending a reply file.

  In the communication system of the present invention, the TCP connection used when the first communication device transmits the transmission file and the second communication device transmits the return file using the same connection, or once the line is disconnected Specify whether to send a reply file using a new TCP connection. Thereby, in the second communication terminal, it is possible to prevent time-consuming processing of the reply file, disconnecting the line during the reply processing, and complicating the processing. For example, when it is known in advance that it takes time to create a reply file, the processing is smoothly performed by setting the mode to disconnect the line once.

  Further, even when the first communication device is designated to send back a reply file while maintaining the TCP connection at the time of transmission of the transmission file, the second communication device performs processing of the reply file under a predetermined condition. If applicable, the communication network is temporarily disconnected. As a result, even in a situation that is not assumed in advance, if the reply process takes time, the communication network is reconnected, so that the process can be completed in a normal state without causing a processing error. it can.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a system configuration diagram of a remote diagnosis system according to the present embodiment. This remote diagnosis system includes a communication terminal 10 installed in the center 1, a relay device 30, and devices 50, 50... Installed in the factory 5. The communication terminal 10 and the relay device 30 are connected via the Internet 2. The relay device 30 and each device 50 are connected via the public telephone line network 4.

  This remote diagnosis system is a system for remotely diagnosing the device 50 in the factory 5 from the center 1 at a remote place. Specifically, the inspection instruction file 61 is transmitted from the communication terminal 10 of the center 1 to the apparatus 50 via the network, and the inspection result performed in the apparatus 50 is communicated as the inspection result file 62 from the apparatus 50 via the network. The system is returned to the terminal 10. Thereby, in the center 1 in a remote place, the state of the apparatus 50 in the factory 5 can be diagnosed.

  Here, the communication terminal 10 and the relay device 30 are always connected to the Internet 2. That is, fixed IP addresses are assigned to the communication terminal 10 and the relay device 30. Therefore, when there is a need to perform communication between the communication terminal 10 and the relay device 30, it is possible to establish a TCP connection by issuing a TCP connection request from either terminal (device). .

  On the other hand, the relay device 30 and each device 50, 50... Are physically connected by the public telephone line network 4, but a dial-up connection is made from the device 50 to the relay device 30. Thus, communication is possible for the first time. Conversely, the relay device 30 cannot make a dial-up connection to the device 50. That is, in order for the relay device 30 and the device 50 to communicate, it is necessary to perform a dial-up connection from the device 50.

  FIG. 2 is a functional block diagram of the communication terminal 10, the relay device 30, and the device 50. The communication terminal 10 includes an inspection instruction file creation unit 11, a communication unit 12, an operation unit 13, a monitor 14, a device database 15, and an inspection start request unit 16.

  The inspection instruction file creation unit 11 is a processing unit that creates an inspection instruction file 61 in which inspection items and inspection instruction commands for the device 50 are described. The inspection instruction file creation unit 11 also performs processing for setting return mode information in the header of the inspection instruction file 61. The operator of the communication terminal 10 operates the operation unit 13 to instruct the inspection instruction file creation unit 11 to create the inspection instruction file 61. The operator creates the inspection instruction file 61 while confirming the inspection content displayed on the monitor 14.

  The reply mode is a mode when the device 50 returns the inspection result file 62 to the communication terminal 10. In this mode, there are an interactive mode and a batch mode. In the interactive mode, the apparatus 50 transmits the inspection result file 62 while maintaining the TCP connection used when the inspection instruction file 61 is received. In the batch mode, the apparatus 50 disconnects the TCP connection used when the inspection instruction file 61 is received, establishes another TCP connection, and transmits the inspection result file 62. More specifically, in the batch mode, after receiving the inspection instruction file 61, the apparatus 50 temporarily disconnects the dial-up connection. When the inspection result file 62 is ready to be transmitted, dial-up connection is established again, and a new TCP connection is established, and the inspection result file 62 is transmitted.

  The communication unit 12 is a processing unit that transmits / receives data to / from another computer using a protocol such as TCP / IP. The communication unit 12 transmits and receives data to and from the relay device 30 via the Internet 2. Alternatively, when the device 50 is dial-up connected, the communication unit 12 transmits and receives data to and from the device 50 via the Internet 2 and the public telephone line network 4.

  The device database 15 is a database related to the devices 50, 50... Installed in the factory 5. Specifically, the device name and the IP address of the device 50 are managed in association with each other. Many devices 50 are installed in the factory 5. In the device database 15, device names and IP addresses related to all these devices 50 are managed in association with each other.

  The inspection start request unit 16 is a processing unit that sends a UDP packet to the device 50 to be inspected when the inspection of the device 50 is started. As described above, the operator instructs the inspection instruction file creation unit 11 to create the inspection instruction file 61. At this time, the operator performs an operation of selecting the inspection target apparatus 50. When this selection operation is performed, the inspection instruction file creation unit 11 refers to the device database 15 and acquires the IP address of the selected device 50. Then, the inspection instruction file creation unit 11 describes the device name and IP address of the device 50 to be diagnosed in the inspection instruction file 61. Therefore, the inspection start request unit 16 can know the IP address of the device 50 that is the diagnosis target by referring to the inspection instruction file 61, and sends out a UDP packet with the IP address as the destination.

  The relay device 30 includes a communication unit 31, a control signal transmission unit 32, a PPP connection unit 33, and a device database 34. The communication unit 31 is a processing unit that transmits and receives data to and from other computers using a protocol such as TCP / IP. The communication unit 31 transmits and receives data to and from the communication terminal 10 via the Internet 2. Further, when the device 50 is performing dial-up connection, the communication unit 31 transmits and receives data to and from the device 50 via the public telephone line network 4.

  The control signal transmission unit 32 is a processing unit that transmits a control signal 63 to the device 50. In this embodiment, the control signal transmission unit 32 transmits the control signal 63 to the apparatus 50 by using the public telephone line network 4 and a specific frequency band that does not interfere with data communication. Other than this, for example, the control signal 63 may be transmitted using radio. Alternatively, a line different from the telephone line may be used.

  Specifically, the control signal 63 transmitted by the control signal transmission unit 32 is a connection start request signal for the device 50. That is, it is a signal for requesting dial-up connection to the device 50 that is not dial-up connected to the public telephone network 4.

  The PPP connection unit 33 is a processing unit that receives a dial-up connection and a PPP (Point to Point) session establishment request from the device 50 and establishes a dial-up connection and a PPP session.

  The device database 34 is a database related to the device 50 installed in the factory 5. Specifically, the device name of the device 50, the identification information of the device 50 (that is, the device identification information specified as the transmission destination of the control signal 63), and the IP address are managed in association with each other. A large number of devices 50, 50... Are installed in the factory 5. In the device database 34, device names, device identification information, and IP addresses related to all these devices 50, 50.

  The device identification information is information that identifies a transmission destination to which the control signal transmission unit 32 transmits the control signal 63. In the device identification information, unique information is given to each device 50 so that each device 50 can be uniquely identified. A large number of devices 50 are installed in the factory 5. Therefore, the relay device 30 needs to identify the device 50 to be inspected and transmit the control signal 63. Therefore, this device identification information is used. Specifically, device identification information is embedded in the control signal 63. The received device 50 receives the control signal 63 if the device identification information of the own device matches.

  The device name and IP address of the device 50 are also registered in the device database 34, which matches the IP address registered in the device database 15 of the communication terminal 10. That is, the relay device 30 reserves an IP address to be assigned in advance to the device 50 that has made dial-up connection. That is, the correspondence of which IP address is assigned to which device 50 is determined in advance. The corresponding information is also reflected in the device database 15 of the communication terminal 10.

  The apparatus 50 includes an inspection result file creation unit 51, a communication unit 52, a control signal reception unit 53, and a PPP connection unit 54. The inspection result file creation unit 51 is a processing unit that creates an inspection result file 62 describing the inspection result after performing the inspection on the device 50. Specifically, the apparatus 50 is inspected based on the inspection item or inspection instruction command described in the inspection instruction file 61 received from the communication terminal 10, and the result is returned to the communication terminal 10 as the inspection result file 62. is there.

  The communication unit 52 is a processing unit that transmits and receives data to and from another computer using a protocol such as TCP / IP. When the device 50 is performing dial-up connection, the communication unit 52 transmits / receives data to / from the relay device 30 via the public telephone line network 4.

  The control signal receiving unit 53 receives the control signal 63 transmitted from the control signal transmitting unit 32. When the device identification information included in the transmitted control signal 63 matches the identification information of the own device, the control signal receiving unit 53 determines that the control signal 63 is a signal for the own device, and the control signal 63 Receive processing.

  The PPP connection unit 54 is a processing unit that makes a dial-up connection request and a PPP session establishment request to the relay device 30. When receiving the control signal 63 that matches the identification information of the own device from the relay device 50, the device 50 requests the relay device 50 to establish a dial-up connection and a PPP session.

  The processing sequence of the remote diagnosis system described above will be described. 3 and 4 are diagrams showing a processing sequence among the communication terminal 10, the relay device 30, and the device 50. FIG. Among these, FIG. 3 shows a processing sequence when the batch mode is designated by the communication terminal 10 as the reply mode. FIG. 4 is a processing sequence when the interactive mode is designated by the communication terminal 10 as the reply mode.

  First, the processing sequence in the batch mode of FIG. 3 will be described. First, the operator operates the communication terminal 10 to give an instruction to start inspection. Specifically, the operator operates the operation unit 13 to perform an operation for specifying the inspection target device 50 and an operation for specifying an inspection item. In response to this operation, the inspection instruction file creation unit 11 creates the inspection instruction file 61. In addition, by specifying an inspection item, a reply mode corresponding to the inspection item is set. Alternatively, the operator may explicitly specify the reply mode. Further, the inspection start request unit 16 transmits a UDP packet to the designated device 50 (step S101).

  As described above, since the inspection start request unit 16 can acquire the IP address of the device 50 that is the transmission destination by referring to the inspection instruction file 61, the inspection start request unit 16 transmits a UDP packet to the IP address. It is. Further, the inspection start request unit 16 specifies the port number of the standby TCP port in the UDP packet. A predetermined number may be used as the port number of the standby TCP port.

  The inspection start request unit 16 sends the UDP packet a plurality of times with a predetermined interval such as 1 second interval. When the inspection start request unit 16 sends out a UDP packet a predetermined number of times, the communication terminal 10 starts measuring a timer and transitions to a TCP connection standby state.

  Next, the relay device 30 relays and receives the UDP packet transmitted from the communication terminal 10. Then, the relay device 30 transmits the control signal 63 to the device 50 corresponding to the transmission destination IP address of the UDP packet (step S102). The relay device 30 can identify the device 50 to which the IP address is assigned by acquiring the IP address of the transmission destination from the UDP packet and referring to the device database 34. Further, the device identification information of the device 50 can be obtained by referring to the device database 34. Therefore, the relay device 30 transmits a control signal 63 designating device identification information to each device 50 using a specific frequency band. Here, the relay device 30 includes information on the IP address and port number of the communication terminal 10 that is the transmission source in the control signal 63.

  Next, the device 50 having the device identification number that matches the designated device identification number receives the control signal 63. Then, the device 50 acquires the IP address and port number of the communication terminal 10 that is the transmission source from the received control signal 63 (step S103).

  Next, the PPP connection unit 54 makes a dial call and establishes a dial-up line network. When the PPP connection unit 33 of the relay device 30 responds to this dial call, a dial-up line network is established (step S104), and when the PPP connection unit 54 makes a PPP session establishment request, the device 50 and the relay device A PPP session is established with 30 (step S105).

  When the PPP session is established, the communication unit 52 of the device 50 subsequently makes a connection request for the TCP connection to the communication unit 12 of the communication terminal 10. Since the communication unit 52 acquires the IP address and port number of the communication terminal 10 in step S103, the communication unit 52 makes a TCP connection request with these as targets. Then, a three-way handshake is performed (step S106), and a TCP connection is established between the device 50 and the communication terminal 10.

  As described above, the remote diagnosis system according to the present embodiment establishes a PPP session from the device 50 that has received a connection request using a UDP packet, and then establishes a PPP session because the same device 50 establishes a TCP connection. At that point, it is possible to establish a TCP connection immediately.

  When a TCP connection is established between the device 50 and the communication terminal 10, the inspection instruction file creation unit 11 sets reply mode information in the header of the inspection instruction file 61. Here, the batch mode is designated (step S107). The inspection instruction file 61 is transmitted to the device 50 via the relay device 30 (step S108).

  Upon receiving the inspection instruction file 61, the apparatus 50 acquires reply mode information from the header of the inspection instruction file 61. Here, since the batch mode is designated, the device 50 transmits a TCP connection disconnection request to the communication terminal 10. Then, a three-way handshake is performed, and the TCP connection between the device 50 and the communication terminal 10 is disconnected (step S109).

  When the TCP connection between the apparatus 50 and the communication terminal 10 is disconnected, the PPP connection unit 54 performs a PPP session disconnection process with the PPP connection unit 33 (step S110), and the dial-up line network disconnection process. Is performed (step S111). In this way, after receiving the inspection instruction file 61, the apparatus 50 temporarily disconnects the TCP connection and the dial-up connection.

  Next, the device 50 analyzes the contents of the inspection instruction file 61 (step S112). That is, the contents of the inspection item or inspection instruction command are analyzed. Then, the inspection is performed according to the inspection items or inspection instruction commands described in the inspection instruction file 61. For example, the motor rotation speed of the device 50, the device temperature of the device 50, the remaining memory capacity of the device 50, and the like are measured. Then, the apparatus 50 creates an inspection result file 62 that records the results of the inspection that has been performed (step S113).

  The apparatus 50 establishes a TCP connection with the communication terminal 10 again when the inspection result file 62 is ready for transmission. Specifically, when the inspection result file 62 is created, the PPP connection request unit 54 makes a dial call again to establish a dial-up network (step S114), and further between the device 50 and the relay device 30. To establish a PPP session (step S115). In other words, after creating the inspection result file 62, the device 50 makes a dial call by itself and performs a dial-up connection without receiving the control signal 63.

  Subsequently, the device 50 makes a TCP connection connection request to the communication terminal 10 and performs a 3-way handshake to establish a TCP connection (step S116). When a new TCP connection is established in this way, the device 50 transmits the inspection result file 62 to the communication terminal 10 using the newly established TCP connection (step S117). When the communication terminal 10 receives the inspection result file 62, the inspection result is displayed on the monitor 14.

  After transmitting the inspection result file 62, the device 50 makes a TCP disconnection request to the communication terminal 10. Then, a three-way handshake is performed and the TCP connection is disconnected (step S118).

  When the TCP connection between the apparatus 50 and the communication terminal 10 is disconnected, the PPP connection unit 54 performs a PPP session disconnection process with the PPP connection unit 33 (step S119), and a dial-up line network disconnection process. Is performed (step S120). In this way, after the inspection result file 62 is transmitted, the TCP connection is disconnected and the dial-up connection is disconnected. In this way, for inspection items that require a long time, the batch mode is used to avoid problems such as disconnection of the line during communication, and the process can be terminated in a normal state.

  Next, an interactive mode processing sequence will be described with reference to FIG. In FIG. 4, steps S201 to S206 are the same as steps S101 to S106 shown in FIG. That is, a TCP connection is established between the device 50 and the communication terminal 10 through steps S201 to S206.

  Next, the inspection instruction file creation unit 11 sets reply mode information in the inspection instruction file 61. Here, the interactive mode is designated (step S207). The inspection instruction file 61 is transmitted to the device 50 via the relay device 30 (step S208).

  Upon receiving the inspection instruction file 61, the apparatus 50 acquires reply mode information from the header of the inspection instruction file 61. Here, since the interactive mode is designated, the apparatus 50 analyzes the contents of the inspection instruction file 61 while maintaining the TCP connection (step S209), and the inspection items or inspections described in the inspection instruction file 61 are analyzed. Perform inspection according to the command. Then, the apparatus 50 creates an inspection result file 62 in which the results of the inspection that has been performed are recorded (step S210).

  When the inspection result file 62 is created, the device 50 transmits the inspection result file 62 to the communication terminal 10 while maintaining the already established TCP connection (step S211). That is, the TCP connection used when the inspection instruction file 61 is received is maintained as it is, and the inspection result file 62 is transmitted. When the communication terminal 10 receives the inspection result file 62, the inspection result is displayed on the monitor 14. As described above, for an inspection item with a short processing time, it is possible to obtain a response in a short time while maintaining the TCP connection by using the interactive mode.

  After transmitting the inspection result file 62, the device 50 makes a TCP disconnection request to the communication terminal 10. Then, a 3-way handshake is performed, and the TCP connection is disconnected (step S212). Further, PPP session disconnection processing is performed (step S213), and dialup line network disconnection processing is performed (step S120). In this way, after the inspection result file 62 is transmitted, the TCP connection is disconnected and the dial-up connection is disconnected.

  The processing sequence of the entire remote diagnosis system including the communication terminal 10, the relay device 30, and the device 50 has been described above. Next, focusing on the communication terminal 10, the flow of remote diagnosis processing for the device 50 will be described. 5 and 6 are flowcharts of remote diagnosis processing in the communication terminal 10.

  As a previous step, an inspection instruction file 61 is created by an operator operation. The inspection instruction file creation unit 11 refers to the apparatus database 15, acquires the IP address of the apparatus 50 that is the diagnosis target designated by the operator, and describes the IP address in the inspection instruction file 61.

  In this state, the examination start request unit 16 first checks whether or not the examination instruction file 61 has been created (step S301). If it has been created, the transmission destination to be diagnosed from the examination instruction file 61 is checked. Is read out (step S302).

  Next, the reply mode is determined from the inspection items registered in the inspection instruction file 61 and recorded in the setting memory or the like (step S303). The communication terminal 10 includes a condition setting file in which each inspection item is associated with a reply mode (batch mode or interactive mode), and determines a reply mode according to the condition setting file. For example, batch modes are associated with inspection items that require time for inspection. Alternatively, the mode may be explicitly selected by the operator. That is, the reply mode may be automatically set from an inspection item or the like, or the reply mode may be set by an operator's manual operation.

  Next, the inspection start request unit 16 acquires information on the number of UDP transmissions and the UDP transmission interval from a UDP transmission definition file stored in a storage unit (not shown) (step S304). A UDP packet is transmitted with the acquired IP address as a target (step S305). For example, a UDP packet is transmitted five times at intervals of one second.

  When the UDP packet is transmitted a predetermined number of times, the communication terminal 10 opens a TCP connection standby port (here, port number N as shown in the figure) and transitions to a TCP connection request standby state. (Step S306). Thus, preparation is made so that a TCP connection can be immediately established when a TCP connection request from the device 50 is generated.

  If no TCP connection request is received (NO in step S307), the timer starts counting (step S308), and the TCP connection request is monitored until a predetermined time elapses (step S309). If a TCP connection request is not received even after a predetermined time has elapsed, a transmission error process for the inspection instruction file 61 is performed (step S310). For example, a message “The transmission of the inspection instruction file has failed.” Is displayed on the monitor 14.

  If a TCP connection request is received in step S307, a mode is designated in the inspection instruction file 61 after establishing a TCP connection (step S311). That is, the reply mode information set in step S303 is written in the header of the inspection instruction file 61. Then, the inspection instruction file 61 is transmitted to the apparatus 50 (step S312). When the inspection instruction file 61 is transmitted, if the interactive mode is set as the reply mode (YES in step S313), it enters a standby state as to whether to receive data (step S314). If no data is received, a timer is set. Is started (step S315), and data reception is waited until a predetermined time elapses (step S316). If no data is received after the predetermined time has elapsed, the interactive mode is designated, but the apparatus 50 may have switched to the batch mode. Transition.

  When the data is received in step S314, the inspection result file 62 is received (step S318). That is, the reception process of the inspection result file 62 returned from the apparatus 50 is performed. Next, TCP disconnection processing is performed (step S319). The contents of the inspection result recorded in the received inspection result file 62 are displayed on the monitor 14, for example. In this way, the communication terminal 10 can obtain the inspection result.

  When the batch mode is designated as the reply mode (NO in step S313), the TCP connection is disconnected in response to a disconnection request from the device 50 (step S320). Thereby, the process proceeds to step S321 in FIG. Alternatively, after a predetermined time has elapsed in step S316 in FIG. 5, when a TCP disconnection request is received from the apparatus 50 in a step (not shown) (change from interactive mode to batch mode), the TCP connection is disconnected, The process proceeds to step S321 in FIG.

  Next, a flowchart of processing related to the batch mode in FIG. 6 will be described. The communication terminal 10 shifts to a TCP connection standby state using the port number obtained by adding 1 to the TCP port number when the inspection instruction file 61 is transmitted (step S321). That is, in step S306, the standby is performed using the port number N, but here, the TCP port of the port number N + 1 is opened and the standby state is set. A rule for adding 1 to the port number in the batch mode is determined in advance with the device 50 and is described in a setting file or the like.

  Then, it waits for a TCP connection request from the device 50 (step S322), and when it does not receive the TCP connection request, it starts counting the timer (step S323). If a connection request is not received until the predetermined time has elapsed (YES in step S324), a transmission error process for the inspection instruction file 61 is performed (step S325). For example, a message “The transmission of the inspection instruction file has failed.” Is displayed on the monitor 14.

  When the TCP connection request is received in step S322, the inspection result file 62 is received (step S326). That is, the reception process of the inspection result file 62 returned from the apparatus 50 is performed. Next, TCP disconnection processing is performed (step S327). The contents of the inspection result recorded in the received inspection result file 62 are displayed on the monitor 14, for example. In this way, the communication terminal 10 can obtain the inspection result.

  7 and 8 are flowcharts of the remote diagnosis process focusing on the device 50. FIG. The device 50 is in a standby state for receiving the control signal 63 from the relay device 30 (step S401). When the control signal 63 is received, it is checked whether the control signal 63 includes an IP address and a port number (step S402). This IP address is the IP address of the communication terminal 10 that is the transmission source of the inspection instruction file 61, and the port number is the port number on which the communication terminal 10 is waiting for a TCP connection request (port number N in this example). . If the IP address or port number is not included, it is another control signal, so other processing (not shown) is executed and the control signal 63 is again in a standby state.

  If the control signal 63 includes an IP address and a port number, the PPP connection unit 54 issues a dial to the PPP connection unit 33 of the relay device 30 to establish a dial-up line network (step S403). . Then, a PPP session is established over the dial-up connection (step S404).

  Subsequently, the communication unit 52 makes a TCP connection request to the communication terminal 10 using the IP address and port number (port number N) acquired in step S302 (step S405). Then, it waits for the TCP connection to be established (step S406). When the TCP connection is established, the reception process of the inspection instruction file 61 is performed (step S407). The device 50 acquires the reply mode information from the received header of the examination instruction file 61, and determines the reply mode (step S408).

  When the interactive mode is designated as the reply mode (YES in step S408), the inspection item or inspection instruction command described in the inspection instruction file 61 is analyzed (step S409), and inspection is performed according to the inspection item or inspection instruction command. To implement. When the inspection is performed, creation of the inspection result file 62 describing the inspection result is started. Then, it is checked whether or not the creation of the inspection result file 62 has been completed (step S410).

  If the creation of the inspection result file 62 has not been completed yet, the timer is started (step S414), and the completion of the inspection result file 62 is waited until a predetermined time has elapsed (step S415). If the inspection result file 62 is not completed even after the predetermined time has elapsed, the process proceeds to the step of FIG. In other words, the interactive mode is specified, but it takes a lot of time to perform the inspection, so the mode is shifted to the batch mode.

  If the inspection result file 62 has been successfully created (YES in step S410), the inspection result file 62 is transmitted to the communication terminal 10 (step S411). In other words, the TCP connection used for the transfer of the inspection instruction file 61 is maintained as it is, and the inspection result file 62 is returned.

  When transmission of the inspection result file 62 is completed, a TCP disconnection process is performed (step S412). Then, the PPP session is disconnected, and finally the dial-up network is disconnected (step S413).

  When the batch mode is determined in step S408 (that is, when the batch mode is specified from the communication terminal 10), or when the predetermined time has passed in step S415 (that is, the interactive mode is specified from the communication terminal 10). However, when a lot of time is required for the inspection time), the process proceeds to the batch mode processing of FIG.

  First, the device 50 makes a TCP disconnection request of the communication terminal 10 and performs a TCP connection disconnection process (step S416), and then disconnects the PPP session and disconnects the dial-up line (step S417).

  In a state where the line is disconnected, the device 50 analyzes the contents of the inspection instruction file 61 (step S418), and performs inspection items according to the contents. Then, the inspection result file 62 is created (step S419).

  When the creation of the inspection result file 62 is completed and the inspection result file 62 is ready to be transmitted, the device 50 makes a dial call to the relay device 30 without waiting for the reception of the control signal 63, and dials up. A line is established (step S420), and a PPP session is established (step S421).

  Then, 1 is added to the TCP port (port number N) used when the inspection instruction file 61 is received, and a TCP connection request is transmitted to the communication terminal 10 by designating the TCP port of the port number N + 1 (step S422). ). As shown in step S321 in FIG. 6, the communication terminal 10 is in an idle state with the TCP port of port number N + 1 open. Thereby, when a TCP connection is established (step S423), the apparatus 50 transmits the inspection result file 62 using the TCP connection (step S424). When the file transmission is completed, TCP disconnection is performed (step S425), and the PPP session and the dial-up line are disconnected (step S426).

  As described above, according to the remote diagnosis system of the present embodiment, when the inspection is started, the UDP packet is transmitted from the communication terminal 10 that transmits the inspection instruction file 61. And the communication terminal 10 which transmitted the UDP packet will be in the standby state of TCP connection. Then, a dial-up line connection and a TCP connection request are made from the device 50 that has received the control signal 63 transmitted based on the UDP packet. Therefore, it is possible to establish a TCP connection immediately when the apparatus 50 establishes a line network by dial-up connection.

  Whether the communication terminal 10 receives the inspection result file 62 while maintaining the TCP connection at the time of transmission of the inspection instruction file 61, or once disconnects the network and newly establishes another TCP connection for inspection. Specify whether to receive the result file. As a result, when a lot of time is required for the execution of the inspection and the generation of the inspection result file 62, the problem that the communication is cut off halfway is avoided.

  That is, as in the present embodiment, when the device 50 and the relay device 30 are in an emergency connection such as a dial-up connection, the line network may be disconnected if data transmission / reception is not detected for a predetermined time. When such a line abnormality occurs while the communication terminal 10 is waiting to receive the inspection result file 62, the recovery process is complicated. Therefore, a time-consuming inspection or the like is determined in advance, and the batch mode is applied to inspection instructions including such inspection items. Thus, the apparatus 50 disconnects the line after receiving the inspection instruction file 61, and establishes the line again when the inspection result file 62 is ready for transmission. Therefore, the occurrence of a line abnormality error during the series of processing is prevented.

  Although the embodiments of the present invention have been described above, the space between the relay device 30 and the device 50 is not limited to a telephone line, and may be a wireless network. That is, the present invention can be applied to a general network in which the apparatus 50 and the relay apparatus 30 are in an emergency connection, and a line can be established only from the apparatus 50. Moreover, it is a condition that the communication terminal 10 and the relay device 30 are always connected, and a dedicated line or the like can be used in addition to the Internet.

It is a system configuration figure of a remote diagnostic system concerning this embodiment. It is a block diagram of each apparatus which comprises a remote diagnostic system. It is a figure which shows the whole process sequence at the time of batch mode of a remote diagnostic system. It is a figure which shows the whole process sequence at the time of the interactive mode of a remote diagnostic system. It is a processing flowchart of a communication terminal. It is a processing flowchart of a communication terminal. It is a process flowchart of the apparatus in a factory. It is a process flowchart of the apparatus in a factory.

Explanation of symbols

1 Center 2 Internet 4 Public telephone network 10 Communication terminal 30 Relay device 50 Device 61 Inspection instruction file 62 Inspection result file 63 Control signal

Claims (3)

A system in which a first communication device and a relay device are always connected, and the relay device and the second communication device are connected by a communication network established by a connection request from the second communication device;
The second communication device is
Means for transmitting a TCP connection request to the first communication device after establishing a communication network by making a connection request to the relay device;
Prepared,
The first communication device is
Means for establishing a TCP connection with the second communication device in response to a TCP connection request from the second communication device, then specifying a return mode and transmitting a transmission file to the second communication device;
With
When the first mode is designated as the reply mode, the second communication device transmits the reply file while maintaining the TCP connection used when the transmission file is received, and the second mode is designated. And disconnecting the communication network with the relay device, establishing the communication network with the relay device again, then establishing a new TCP connection and transmitting a reply file. A communication system. The communication system according to claim 1,
The second communication device disconnects the communication network with the relay device, and then establishes the communication network again when the reply file is ready for transmission. The communication system according to claim 1,
Even if the first mode is designated as the reply mode, the second communication apparatus determines that the time required for the reply file reply process satisfies a predetermined condition, and then repeats the relay apparatus. The communication system is characterized in that the communication network between the communication device and the relay device is disconnected, the communication network between the relay device and the relay device is established again, and then a new TCP connection is established and a reply file is transmitted.

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