JP2010050872A - Data transmission system, and data transmission control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To continue data transmission while detouring a position where a fault occurs, regarding a data transmission system and data transmission control method. <P>SOLUTION: Transmission/reception control processing sections 2-1 to 2-5 of a plurality of transmission apparatuses 1-1 to 1-5 are sequentially connected in series by duplexed transmission lines L0, L1 and detour control processing sections 4a and 4b are connected to the transmission/reception control processing sections 2-1 and 2-5 of one and another transmission apparatuses 1-1 and 1-5 positioned at both terminals. A close-range information frame containing a life value is transmitted/received in a prescribed term, and it is determined from a receiving state of the close-distance information frame whether or not any fault occurs on a transmission path. If any fault occurs, only the information frame scheduled to pass through a position where the fault occurs, is controlled by the detour control processing section 4a, 4b so as to be transmitted via a detour network 6. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  In the present invention, a plurality of transmission devices are sequentially connected in series by transmission lines of the 0 system and the 1 system, and the transmission apparatuses located at both ends are connected by a detour network. Data is transmitted between transmission devices via the transmission line, and when a failure occurs in one or both of the 0 system and 1 system, the data is transmitted by bypassing the location of the failure via the bypass network. The present invention relates to a continuable data transmission system and a data transmission control method.

  There are known systems that place multiple transmission devices along highways and rivers to collect observation information and notify management control information. In such systems, they correspond to the start and end points. A plurality of transmission devices are respectively arranged at a predetermined distance between the transmission devices to be connected, and are sequentially connected in series by a transmission path. Also, in a transmission system in which a plurality of multiplexing devices are sequentially connected by a dedicated line, the failure occurrence points in the dedicated line and the multiplexing device are detoured by using a public ISDN line to repair the failure. Means have been proposed (see, for example, Patent Document 1). Relatively many systems have been known to improve reliability by making the transmission line duplexed between the 0 system and the 1 system, and a plurality of transmission devices are provided by a double ring-shaped high-speed transmission line of the 0 system and the 1 system. A data transmission system is configured by connecting the two, so that data transmission can be continued even in the event of a double failure in which the transmission lines of system 0 and system 1 fail simultaneously. There is a system in which devices are connected by a low-speed network, and this is used as a detour route for a high-speed transmission path. It has been proposed (see, for example, Patent Document 2).

In addition, since data transmission is interrupted due to the occurrence of a failure, it is required to quickly detect this and perform recovery processing to improve the reliability of the data transmission system. There is known a system for sending and confirming normality. In such a system, the transmission device under test returns the received test data by forming a loop back to the test data transmission side, and the test data transmission side transmits the test data transmitted. There is also known a system in which normality can be confirmed by collation matching with test data received and returned (see, for example, Patent Document 3).
JP 2000-22704 A JP 2003-283519 A JP 2005-203914 A

  A plurality of transmission devices are sequentially connected in series by transmission lines of system 0 and system 1, and data transmitted in the direction from the transmission device located at one end to the transmission device located at the other end is, for example, transmission of system 0 A data transmission system that uses a single transmission line to transmit data transmitted from a transmission device located at the other end to a transmission device located at the other end using a transmission line. Data transmission is possible between transmission apparatuses. However, if a failure occurs in any of the transmission paths including the transmission lines of the 0 system and the 1 system, there is a problem that data transmission is impossible between the transmission apparatuses that use the failure occurrence location as the data transmission path. Therefore, as shown in the above-mentioned Patent Document 2, it is possible to avoid complete interruption of data transmission due to the occurrence of a failure by connecting each transmission apparatus in a ring shape by a completely duplexed transmission path and by providing a spare low-speed network. can do. However, since the system configuration is large, the system cost is a problem.

  Data transmitted through the transmission path including the location where the failure occurred is interrupted until the failure is recovered. Therefore, it is necessary to quickly detect the occurrence of a failure and start a detour process or a recovery process. A transmission device generally has a configuration with a reception interruption detection function, and it is possible to detect the occurrence of a failure by this reception interruption detection function. Since reception interruption is detected, it is not easy to identify the actual failure location. Therefore, it is conceivable to sequentially perform the folding test, but there is a problem that it takes a relatively long time.

  An object of the present invention is to solve the above-mentioned conventional problems, and in the event of a failure in a system in which a plurality of transmission apparatuses are serially connected in series via transmission lines of system 0 and system 1, a bypass network is provided. Thus, it is possible to continue the data transmission by the information frame by bypassing the location where the failure occurs, and to improve the reliability at a low cost.

  The data transmission system of the present invention is a data transmission in which a plurality of transmission apparatuses each having a transmission / reception control processing unit for performing transmission / reception control of data by an information frame are sequentially connected in series by a duplex transmission path of 0-system and 1-system. A detour control processing unit connected to transmission / reception control processing units of one and the other transmission devices located at both ends of a plurality of transmission devices sequentially connected in series by transmission lines of system 0 and system 1 The detour control processing unit is scheduled to pass through a transmission failure detection means for either or both of the 0-system and 1-system duplex transmission paths and the transmission failure occurrence location detected by the detection means. Means for performing detour transfer control of the information frame via the detour network.

  The bypass control processing unit connects the source address as its own address, the destination address as an address for sequentially specifying the transmission control processing unit corresponding to a plurality of transmission devices, and the life value between one and the other bypass control processing unit. Means for transmitting a short distance information frame having a value obtained by adding 1 to the number of transmission / reception control processing units transmitted at a predetermined cycle, and transmission for receiving this short distance information frame and having a life value of 1 Means for determining whether the path is normal or no transmission even after the predetermined period has elapsed or the received transmission line abnormality is the life value abnormality, and the transmission / reception control processing unit sends out from one detour control processing unit Means is provided for subtracting 1 from the life value of the short distance information frame and transferring it to the other detour control processing unit.

  The transmission / reception control processing unit generates a near field information frame having a source address as its own address, a destination address as a broadcast address, and a life value as a maximum value based on a predetermined number of bits at a predetermined cycle, The life value of the short distance information frame is received by receiving the short distance information frame from the means for sending to the transmission path with the 1 system and the transmission / reception control processing unit connected oppositely by the transmission path between the 0 system and the 1 system. The information frame addressed to its own address by the transmission path which shows a larger value by comparing the life value of the short distance information frame received through the transmission path of the 0-system and the 1-system with the means for subtracting 1 from the transmission path Is configured to receive.

  Further, the bypass control processing unit between one and the other connected via the bypass network is oppositely connected via the bypass network when it is determined that the transmission path is abnormal by means for determining whether the transmission path is normal or the transmission path is abnormal. A detour request is sent to the detour control processing section, and an information frame that passes through the location determined to be abnormal in the transmission path is sent to the detour control processing section that is oppositely connected via the detour network.

  In the data transmission control method of the present invention, a plurality of transmission apparatuses each having a transmission / reception control processing unit for performing transmission / reception control of data are sequentially connected in series by duplex transmission lines of 0 system and 1 system. Is a data transmission control method for transmitting data between information frames, and is connected to transmission / reception control processing units of one and the other transmission devices located at both ends of a plurality of transmission devices sequentially connected in series by a transmission line. The detour control processing unit is connected between the detour control processing unit of one and the other, with the source address as its own address, the destination address as an address for sequentially specifying a plurality of transmission devices, and the life value in a predetermined cycle. The process of sending out a short-distance information frame having a value obtained by adding 1 to the number of transmission / reception control processing units in a predetermined cycle, and the detour control processing unit between one and the other include a short-distance information frame. Whether or not the transmission path is abnormal is determined based on whether or not transmission / reception is normally performed, and when it is determined that the transmission path is abnormal, a detour request is sent to the detour control processing unit connected oppositely via the detour network. And a process of sending an information frame passing through the location where the transmission line abnormality occurs to the bypass control processing unit via the bypass network.

  In addition, when the transmission path abnormality occurs, the bypass control processing section bypasses and transmits the information frame between the transmission and reception control processing sections via the bypass network, and the normal reception of the short-range information frame returns the transmission path abnormality occurrence location to the normal state. This includes a process of notifying that there is no detour request via the detour network and discarding the information frame of the transmission destination address that has been detour transferred via the detour network.

  In the transmission / reception processing units of multiple transmission devices, determine whether the reception status of the short-distance information frame with a predetermined period is normal or abnormal, and if it cannot be received, determine that an abnormality has occurred on the previous stage along the transmission path. By transferring only the information frame that is scheduled to pass through the location where the anomaly has occurred through the bypass network under the control of the bypass control processing unit, even when a double failure occurs in the duplexed transmission path of the 0 system and the 1 system, Data transmission using information frames can be continued, and the existing network such as Ethernet (registered trademark) can be used as a detour network, thus suppressing an increase in system cost and improving data transmission reliability. can do.

  The data transmission system of the present invention will be described with reference to FIG. 1. A plurality of transmission apparatuses 1-1 to 1- 1 each having transmission / reception control processing units 2-1 to 2-5 that perform transmission / reception control of data using information frames. 5 is a data transmission system in which serially connected transmission lines L0 and L1 of 0 system and 1 system are connected in series, and serially connected in series by transmission lines L0 and L1 of 0 system and 1 system. Detour control processing units connected to transmission / reception control processing units 2-1 and 2-5 of transmission devices 1-1 and 1-5 located at both ends of a plurality of transmission devices 1-1 to 1-5, respectively. 4a and 4b, and the detour control processing units 4a and 4b detect a transmission failure in either one or both of the transmission lines L0 and L1 in which the 0 system and the 1 system are duplexed, and detect by the detecting means. Information scheduled to pass through the location where the transmission failure occurred The frame, and means for controlling reroute via the bypass network 6.

  Also, the data transmission control method of the present invention has a plurality of transmission apparatuses 1-1 to 1-5 each having transmission / reception control processing units 2-1 to 2-5 for performing transmission / reception control of data. A data transmission control method for transmitting data by an information frame between transmission apparatuses sequentially connected in series via the transmission lines L0 and L1, and a plurality of transmission apparatuses connected in series via the transmission lines L0 and L1 From detour control processing units 4a and 4b connected to the transmission / reception control processing units 2-1 and 2-5 of the transmission apparatuses 1-1 and 1-5 located at both ends of 1-1 to 1-5, respectively. In a predetermined cycle, the source address is the own address, the destination address is the address that sequentially designates the plurality of transmission apparatuses 1-1 to 1-5, and the life value is between the detour control processing units 4a and 4b between one and the other. Send / receive control processing connected to The process of sending a short distance information frame having a value obtained by adding 1 to the number of 2-1 to 2-5 at a predetermined period, and the detour control processing units 4a and 4b between one and the other It is determined whether or not the transmission path is abnormal depending on whether transmission / reception is normally executed. When it is determined that the transmission path is abnormal, a detour request is sent to the detour control processing units 4a and 4b that are connected to each other via the detour network 6. And a process of sending an information frame that passes through the location where the transmission line abnormality occurred to the bypass control processing unit via the bypass network 6.

  FIG. 1 is an explanatory diagram of a first embodiment of the present invention, in which 1-1 to 1-5 are transmission apparatuses, 2-1 to 2-5 are transmission / reception control processing units, 3 is a terminal control processing unit, and 4a and 4b. Is a detour control processing unit, 5 is a terminal, 6 is a detour network, and L0 and L1 are transmission lines of the 0 system and the 1 system. The transmission devices 1-1 to 1-5 are sequentially connected in series by the transmission lines L0 and L1 of the 0 system and the 1 system. Each of the transmission devices 1-1 to 1-5 has a configuration including transmission / reception control processing units 2-1 to 2-5 and a terminal control processing unit 3, and transmits transmissions of 0 system and 1 system in series. The bypass control processing unit 4a is connected to the transmission / reception control processing units 4a and 4b of the transmission devices 1-1 and 1-5 located at both ends of the transmission devices 1-1 to 1-5 connected by the paths L0 and L1, respectively. , 4b are connected, and the detour control processing units 4a and 4b are connected by the detour network 6, and the detour control processing is performed only when one or both of the transmission paths L0 and L1 of the 0-system and 1-system occur. Only the information frames scheduled to pass through the location where the failure has occurred are routed through the bypass network 6 by the units 4a and 4b.

  The detour control processing units 4a and 4b connected to the transmission / reception control processing units 2-1 and 2-5 of the transmission devices 1-1 and 1-5 with one end and the other end sequentially connected in series by the transmission lines L0 and L1 are as follows. As transmission / reception apparatuses 1-1 and 1-5, transmission / reception control processing units 2-1 and 2-5 of transmission apparatuses 1-1 and 1-5 are respectively performed by transmission lines L0 and L1 of system 0 and system 1 respectively. The control processing functions of the transmission / reception control processing units 2-1 and 2-5 can be expanded to realize the functions of the detour control processing units 4a and 4b. It is. The bypass network 6 can also apply an existing LAN such as Ethernet (registered trademark). The transmission lines L0 and L1 between the 0 system and the 1 system are optical transmission lines, and the transmission / reception control processing units 2-1 to 2-5 convert the optical signal into an electrical signal and the electrical signal into the optical signal. It is also possible to adopt a configuration in which an electro-optic conversion unit is provided.

  Also, when the transmission lines L0 and L1 between the 0 system and the 1 system are normal, for example, as shown by the arrows, the transmission system 1-1 side at one end is connected to the transmission apparatus 1-5 side at the other end. An information frame can be transmitted via the transmission line L0, and the information frame can be transmitted from the transmission apparatus 1-5 at the other end to the transmission apparatus 1-1 at the other end via the one-system transmission line L1. . Such data transmission by the information frame between the transmission apparatuses 1-1 to 1-5 is performed by the respective transmission / reception control processing units 2-1 to 2-5, and whether or not the data is addressed to the own apparatus by the transmission destination address. If it is addressed to another device, it is transmitted to the next transmission device. If it is addressed to its own device, the information frame is received and transferred to the terminal control processing unit 3, and the terminal control processing unit 3 The data is transferred from the terminal 5 to the terminal 5. The data from the terminal 5 is transferred to the transmission / reception control processing units 2-1 to 2-5 via the terminal control processing unit 3, and sent to the 0-system or 1-system transmission path according to the transmission destination address. Also, different addresses are assigned to the transmission / reception control processing units 2-1 to 2-5 and the detour control processing units 4a and 4b, respectively. If they are packaged, they can be managed as package addresses. It is. It should be noted that the number of transmission devices connected can be further increased, and conversely, the number can be reduced. Further, although only one terminal 5 is shown corresponding to the transmission device, the number of terminals 5 can be increased, and other data processing systems can be connected.

  Each of the transmission / reception control processing units 2-1 to 2-5 and the detour control processing units 4a and 4b transmits a short-distance information frame at a predetermined cycle in order to check the normality of each unit. In this case, the information frame can be distinguished from the information frame for normal data transmission by an identifier or the like, and the short-range information frame from each of the transmission / reception control processing units 2-1 to 2-5 has the transmission source address as its own address and transmission. If the destination address is a broadcast address and the initial value of the life value is an 8-bit configuration, the maximum value is “FF”. In the case of a 4-bit configuration, the maximum value is “F” (= “1111”). The short-distance information frames from the detour control processing units 4a and 4b have the transmission source address as their own address, the transmission destination address as the address of each of the transmission / reception control processing units 2-1 to 2-5, and the life value. In addition, 1 is added to the number N of the transmission / reception control processing units 2-1 to 2-5 (N + 1). The life value is decremented by 1 every time the short-distance information frame is transferred, and when it is received by the 0-system transmission line L0, the life value is transferred to the 0-system transmission line L0 and received by the 1-system transmission line L1. In this case, the data is transferred to the system 1 transmission line L1. Accordingly, the life value of the short-distance information frame from the detour control processing unit 4a indicates the case where the number N of the transmission / reception control processing units 2-1 to 2-5 is 5, and therefore the initial value of the life value is N + 1 = 6. It becomes. Since 1 is subtracted every time transfer processing is performed by the transmission / reception control processing units 2-1 to 2-5, the life when the short-distance information frame from the detour control processing unit 4a is normally received by the detour control processing unit 4b. The value is 1. Also, since the initial value of the life value of the short-range information frame transmitted from the transmission / reception control processing units 2-1 to 2-5 is "FF", 1 is subtracted for each transfer process, and "FE", "FD" "," FC ", and so on. Accordingly, by associating with the transmission source address, the connection order of the 0-system transmission line L0 and the 1-system transmission line L1 to the own apparatus is recognized, and the address table is formed by the transmission source address of the short-distance information frame. Can do.

  Further, when a transmission failure occurs, the bypass control processing units 4a and 4b can receive the short-range information frame from the transmission / reception control processing unit of the transmission device on the own device side, but cannot receive any other information. Thereby, a detour request is sent to the opposite detour control processing unit via the detour network 6. In this case, for example, referring to the address table, a transfer request including the transmission source address and the transmission destination address of the information frame to be detoured can be transferred to the opposite detour control processing unit via the detour network 6. When the failure is recovered, normal reception of the short-distance information frame becomes possible, so that the opposite detour control processing unit is notified that there is no detour request, and detour transfer is stopped. Further, after a normal state without a detour request is obtained, the detour control processing units 4a and 4b stop detour transfer via the detour network 6 and discard the received information frame.

  FIG. 2 is an explanatory diagram of the main part of the transmission / reception control processing unit, and shows the main part of the transmission / reception control processing units 2-1 to 2-5 in FIG. In the figure, 2 is a transmission / reception control processing unit, 11a and 11b are frame collection units, 12a and 12b are frame generation units, 13 is a transmission frame insertion unit, 14 is a reception frame determination unit, 15 is an information recording unit, 16 Is a life value insertion unit, 17 is a MAC-SA insertion unit, 18 is a time passage determination unit, 19 is a reception path determination unit, L0 and L1 are transmission lines of the 0 system and 1 system, and these transmission paths L0 and L1 The above-described information frame and short-range information frame (hereinafter referred to as “frame” when including an information frame and a short-range information frame) are transmitted to and from the opposite device. A frame transmitted from the one opposing device via the 0-system transmission line L0 is received by the frame collecting unit 11a, and a frame transmitted from the other opposing device via the 1-system transmission line L1 is received by the frame collecting unit 11b. The received frame is transferred to the received frame determination unit 14.

  The reception frame determination unit 14 is either a time lapse determination unit 18 including a determination unit for determining whether or not the short-distance information frame has been received at a predetermined interval, and one of the 0-system and 1-system transmission paths based on the comparison of the reception life value. Including the function of the reception path determination unit 19 that determines the path of the received frame, and further includes a function for determining whether or not the transmission destination address of the received frame, which is not shown, indicates the own apparatus address, For example, a function for transferring to the terminal control processing unit 3 (see FIG. 1), and a function for transferring a frame addressed to another device to the transmission frame inserting unit 13, and a function for receiving control processing for the short distance information frame described above. Is also included. This near field information frame reception control processing function forms an address table in the information recording unit 15 using the source address and life value added to the received near field information frame in the initial state. It also includes functions. In addition, when a short distance information frame is received, a processing function of transferring to the transmission frame inserting unit 13 is also included.

  The transmission frame insertion unit 13 includes functions of the life value insertion unit 16 and the MAC-SA insertion unit 17, and transmits a frame to the first transmission line L1 via the frame generation unit 12a. It also includes a selection control function for transmitting a frame to the 0-system transmission line L0 via 12b. If the frame received via the 0-system transmission line L0 is not addressed to the own apparatus, the frame generator 12b sends the frame to the 0-system transmission line L0, and the frame received via the 1-system transmission line L1 is not addressed to the own apparatus. In this case, the data is sent to the first transmission line L1 via the frame generation unit 12a. The transmission destination address can be set using the address table formed in the information recording unit 15 described above. The life value insertion unit 16 performs a process of subtracting 1 from the life value of the received short-range information frame and a process of setting the life value of the short-range information frame having the own device address as the transmission source address SA to “FF”. Includes functionality. The MAC-SA insertion unit 17 has a function of referring to the address table formed in the information recording unit 15 and adding it as the source address SA of the above-mentioned short distance information frame and data transmission frame.

  FIG. 3 is an explanatory diagram of a main part of the detour control processing unit, and shows the detour control processing unit 4b, the detour network 6, the detour control processing unit 4a, and the counter device in FIG. This corresponds to the transmission device 1-4 or the transmission / reception control processing unit 2-5. The detour control processing unit 4b shows a case where it has a configuration including frame collection units 21a and 21b, frame generation units 22a and 22b, transmission frame insertion units 23a and 23b, and an information recording unit 24. The unit 4a has the same configuration, and the information recording unit 24 can collect and store the reception record information of the short distance information frame in the address table and the transmission / reception control processing unit of each transmission device. .

  The transmission frame insertion unit 23a includes a MAC-SA insertion unit 25 and a life value insertion unit 26, and is transferred from the opposite detour control processing unit 4a via the detour network 6 and transmitted by the frame collection unit 21a during detour control. This has a function of performing detour control for transmitting the received information frame via the frame generation unit 22 and also has a function of transmitting a short-range information frame at a predetermined cycle. Also, the transmission frame insertion unit 23b identifies whether or not the short distance information frame from the opposite bypass control processing unit 4a can be received at a predetermined cycle. 6 has a control function of transferring an information frame to the opposing detour control processing unit 4a. Further, at the time of detour control, it is determined whether the information frame received by the frame collection unit 21b is an information frame to be detoured, and if it is determined to be an information frame to be detoured, it is determined from the frame generator 22a via the detour network 6. When it is determined that there is no need to send it to the opposite detour control processing unit 4a and perform detour transfer, it has a function of discarding the information frame.

  FIG. 4 is an explanatory diagram of the life value of the short-range information frame, and the transmission of the life value of the short-range information frame from the detour control processing unit and the life value of the short-range information frame from each transmission / reception control processing unit. 1 shows an example of a time value. The codes of the detour control processing units 4a and 4b and the transmission / reception control processing units 2-1 to 2-5 in FIG. 1 are used as the respective addresses, and 5 between the detour control processing units 4a and 4b. A case will be described in which the transmission / reception control processing units 2-1 to 2-5 are connected by transmission lines of the 0 system and the 1 system. Five transmission / reception control processing units 2-1 to 2-5 are connected to the life value of the short-range information frame transmitted from the detour control processing units 4a and 4b shown as the life value (detour control processing unit) of the short-range information frame. Therefore, the short distance information frame is transmitted at a predetermined cycle with the initial value set to N + 1 = 6 and the transmission destination address as the addresses of the transmission / reception control processing units 2-1 to 2-5 sequentially.

  Each of the transmission / reception control processing units 2-1 to 2-5 records the reception status information as reception when the transmission destination address of the short-distance information frame indicates the own transmission / reception control processing unit. The life value is decremented by 1 and transferred. Therefore, the life values of the short-distance information frames transmitted from the detour control processing units 4a and 4b are sequentially 6, 5,. Thereby, each of the transmission / reception control processing units 2-1 to 2-5 can recognize the connection order from the detour control processing units 4a and 4b. For example, since the transmission / reception control processing unit 2-4 receives the short-range information frame from one bypass control processing unit 4a via the transmission / reception control processing unit 2-3, the life value at the time of reception is 3. When transferring it from the transmission / reception control processing unit 2-3, 1 is subtracted to set the life value to 2. Therefore, the connection order from one detour control processing unit 4a is 4−4 = 4. Can be recognized. Similarly, since the reception life value is 5 and the transmission life value is 4 by 1 subtraction, the connection order from the other detour control processing unit 4b can be recognized as 2nd by 6-4 = 2. .

  In addition, the transmission / reception control processing units 2-1 to 2-5 in the case of showing the life value (transmission / reception control processing unit) of the short-distance information frame uses the transmission source address as its own address, the transmission destination address as the broadcast address, and the life value as the life value. The short distance information frame set to “FF” is transmitted at a predetermined cycle. This life value is also decremented by 1 every time it is transferred by the transmission / reception processing unit. Accordingly, the life value “FF” of the initial value of the short-distance information frame transmitted from the transmission / reception control processing unit 2-1 in the direction of the transmission / reception control processing unit 2-5 is sequentially subtracted by 1 every time it is transferred. “FD” and “FC”. For example, the life value when the transmission / reception control processing unit 2-4 receives the short-range information frame transmitted from the transmission / reception control processing unit 2-2 is “FE”, and the life value when the short-range information frame is forwarded and transmitted Is “FD”. Similarly, the life value of the short distance information frame transmitted from the transmission / reception control processing unit 2-5 in the direction of the transmission / reception control processing unit 2-1 is also “FF”, “FE”, “FD”, and “FC”.

  Each of the transmission / reception control processing units 2-1 to 2-5 can recognize the connection order from the detour control processing units 4a and 4b as described above, and from the transmission / reception control processing units 2-1 to 2-5. Based on the life value of the short-range information frame, it can be determined whether to receive from the 0-system transmission line L0 or from the 1-system transmission line L1. For example, in the transmission / reception control processing unit 2-2, when the transmission destination address is 2-1, the life value of the short-distance information frame with the transmission destination address 2-2 is “FE”. In the connection configuration, the data is received on the 0-system transmission line L0.

  FIG. 5 is an explanatory diagram of the reception state information according to the first embodiment of the present invention, showing the device address, the reception state, and the detour request state. The device address is the transmission / reception control processing unit 2-1 to 2 shown in FIG. Shown as the same as −5. When the apparatus is started up, a correspondence table between the apparatus address and the reception state and a recording area of a bypass request state indicating whether or not a bypass request is made are formed in the information recording unit 24 (see FIG. 3). At the time of this initialization, all reception states are not received, and the bypass request state is no bypass request. Then, with reference to the transmission source address of the short-distance information frame of a predetermined period when the operation is started, when there is a normal transmission path, the presence of reception is recorded corresponding to the address. When this transmission line is normal, the bypass request state remains without a bypass request. When a transmission line is abnormal, it is possible to receive from a transmission device closer to the location where the abnormality has occurred, but it is impossible to receive from a transmission device farther than the location where the abnormality has occurred, and there is no reception corresponding to the device address of the transmission device. . In the illustrated case, the device addresses 2-1 to 2-3 are in a receiving state with reception, but the device addresses 2-4 and 2-5 are in a case of no reception. If there is even one reception state without such reception, the detour control processing units 4a and 4b perform a detour request to the opposite detour control processing unit when the detour request state is no detour request, and change the detour request state. Update during detour requests. That is, the transmission line is in an abnormal state (continuation). When all reception statuses are received due to transmission line error recovery, a detour stop request is sent to the opposite detour control processing unit, the detour request status in the detour request state is updated without detour request, and the transmission path is normal Return to.

  FIG. 6 is a flowchart of the short distance information frame transmission / reception process of the transmission / reception control processing unit. A short distance information frame having a transmission source address as its own address, a transmission destination address as a broadcast address, and a life value as FF is set to 0 at a predetermined cycle. It transmits to the system transmission line and the system 1 transmission line (A1). Also, a short-distance information frame is received from the opposite device (A2), and the reception state is confirmed and determined (A3). In the case of normal reception, the life value is recorded in the information recording unit 15 (see FIG. 2) (A4), the life value is decremented by 1, and transmitted to the opposite apparatus via the transmission line of the same system as the reception system. (A5). If normal reception is not possible, the life value is recorded as 0 in the information recording unit 15 (A6). The life values corresponding to the transmission lines of system 0 and system 1 recorded in the information recording unit 15 are compared, and the transmission line with the larger life value is selected (A7). When an information packet addressed to the own address is received, an information frame from the selected transmission path is received (A8). These steps (A1) to (A8) are repeated every predetermined period.

  FIG. 7 shows a flowchart of short distance information frame transmission / reception processing of the detour control processing unit, where the transmission source address is its own address, the life value is N + 1 (N = the number of transmission devices or the number of transmission / reception control processing units), and the transmission destination address Is transmitted at a predetermined cycle (B1). In one bypass control processing unit 4a, the reception status of the short distance information frame from the other bypass control processing unit 4b is confirmed, and in the other bypass control processing unit 4b, one bypass control processing unit The reception state of the short distance information frame from 4a is confirmed (B2). When there is no reception, the process proceeds to step (B4), and when there is reception, the reception state is set as “reception” (B3), and the process proceeds to step (B4). In step (B4), the information on the reception state is notified to the opposite bypass control processing unit, and the bypass control processing units 4a and 4b of one and the other determine whether or not a bypass execution request is possible.

  This step (B4) includes steps (C1) to (C5) shown in FIG. 8, and a short-distance information frame from all devices (all transmission / reception control processing units) for determining whether or not a bypass execution request is possible. Are collected and checked (C1). Then, it is determined whether or not all are in a receiving state (C2). If no reception is included, the transmission path is abnormal. If the detour start request is not transmitted, a detour start request by the detour network is transmitted (C3). If all reception is received, the transmission path is normal. If the detour stop request has not been transmitted, a detour stop request by the detour network is transmitted (C4). Then, the reception state of the short-range information frame from all devices (all transmission / reception control processing units) is reset (C5), and collection of the reception state information is started again.

  Then, upon completion of step (B4) and steps (C1) to (C5), the reception state of the information frame is determined (B5). If there is reception, the state of presence / absence of a detour request is determined (B6), When there is a detour request, the received information frame is transmitted to the detour network (B7), and when there is no detour request, the received information frame is discarded (B8). Then, including the case where no information frame is received, it is determined whether or not the information frame is received via the bypass network (B9), and when the information frame transferred from the opposite bypass control processing unit via the bypass network is received Then, the data is transmitted to the opposite device (transmission / reception control processing unit) (B10), and the process is terminated including the case of no reception. The detour control processing unit repeats the steps (B1) to (10) described above at a predetermined cycle.

  FIG. 9 is an explanatory diagram when a failure occurs in the 0-system transmission path, and the same reference numerals as those in FIG. 1 denote the same names. As a failure occurrence, for example, when a failure occurs in the 0-system transmission line L0 indicated by a mark X between the transmission devices 1-2 and 1-3, the transmission devices 1-3 to 1-5 are connected from the transmission device 1-2 side. And short-distance information frames with a predetermined period cannot be received via the 0-system transmission line L0. In such a failure occurrence situation, the detour control processing unit 4b can receive the short-range information frame from the transmission apparatuses 1-3, 1-4, and 1-5 via the 0-system transmission path L0. Short-distance information frames from the detour control processing unit 4a and the transmission / reception control processing units 2-1 and 2-2 cannot be received. At this time, the device address and reception state information shown in FIG. 5 are not received by the detour control processing unit 4b, but the device addresses 2-1 and 2-2 are not received, and the device addresses 2-3, 2-4, and 4-4. 2-5 is reception.

  Therefore, the detour control processing unit 4b sends a detour request corresponding to the reception state information to the detour control processing unit 4a via the detour network 6. In this case, an information frame detour request is made with the device addresses 2-1 and 2-2 as the transmission source addresses and the transmission destination addresses as the device addresses 2-3, 2-4, and 2-5. In response to the detour request, the detour control processing unit 4a transmits information to the transmission devices 1-3 to 1-5 to the transmission / reception control processing units 2-1 and 2-2 of the transmission devices 1-1 and 1-2. An instruction is given to send the frame to the 1-system transmission line L1. Thereby, for example, in the transmission / reception control processing unit shown in FIG. 2, the transmission apparatuses 1-3 to 1-5 sent from the transmission frame insertion unit 13 to the 0-system transmission line L0 via the frame generation unit 12b. The transmission / reception control processing units 2-3 to 2-4 are controlled to be sent from the frame generation unit 12a to the first transmission line L1. Therefore, the information frame addressed to the transmission / reception control processing unit 2-3 from the transmission / reception control processing unit 2-2 is transmitted via the detour network 6 indicated by a dotted line. In this case, there is a possibility that the 1-system transmission line L1 between the transmission apparatuses 1-1 and 1-2 may be in a congested state, but it is possible to avoid congestion by applying a known control means such as transmission restriction. Can also be done. Further, when the information frame addressed to the transmission / reception control processing unit 2-2 of the transmission apparatus 1-2 is transferred, the detour control processing unit 4a performs detouring on the information frame as shown in step (B8) of FIG. Discard as no request.

  Further, when the above-described failure of the 0-system transmission line L0 is recovered, the short-range information frame transmitted at a predetermined cycle can be received. For example, as shown in FIG. It will be. Thereby, the detour control processing unit 4 b transmits a detour stop request to the detour control processing unit 4 a via the detour network 6. Receiving the detour stop request, the detour control processing unit 4a instructs the transmission / reception control processing units 2-1 and 2-2 to return to the initial transmission state. Then, the information frame transmission via the detour network 6 between the detour control processing units 4a and 4b is stopped.

  FIG. 10 is an explanatory diagram when a failure occurs in both the 0-system and the 1-system transmission paths. The same reference numerals as those in FIGS. 1 and 9 indicate the same names, and the transmission apparatuses 1-3 and 1-4 are connected. When the failure indicated by the mark X occurs in the 0-system transmission line L0 and the 1-system transmission line L1, the detour control processing unit 4a has the transmission source addresses from the transmission devices 1-4 and 1-5 and the detour control processing unit 4b. The detour control processing unit 4b cannot receive the information frame or the short-distance information frame of the transmission devices 1-1 to 1-3 and the detour control processing unit 4a. Cannot receive. As the reception status information in this case, the detour control processing unit 4a receives the device addresses 2-1, 2-2, and 2-3 as the reception status information shown in FIG. 5 indicates no reception, and in the detour control processing unit 4b, the device addresses 1-1, 2-2, and 2-3 are not received, and the device addresses 2-4 and 2-5 are received.

  Thereby, the detour control processing unit 4a determines that a failure has occurred in the 1-system transmission line L1 between the transmission devices 1-3 and 1-4, and the detour control processing unit 4b determines that the transmission devices 1-3, 1 -4, it can be determined that a failure has occurred in the 0-system transmission line L0. Then, the detour control processing units 4 a and 4 b send detour requests to each other via the detour network 6. As a result, the detour control processing unit 4a sends, to the transmission / reception control processing units 2-1 to 2-3, data whose transmission destination addresses indicate the transmission apparatuses 1-4 and 1-5 to the 1-system transmission line L1. To instruct. Further, the detour control processing unit 4b sends, to the transmission / reception processing units 2-4 and 2-5, data whose transmission destination addresses indicate the transmission devices 1-1 to 1-3 to the 0-system transmission line L0. Instruct. As a result, data from the transmission device 1-3 to the transmission device 1-4 is transmitted to the first-system transmission line L1, and the transmission device 1-1 is routed from the detour control processing unit 4a of the transmission device 1-1 via the detour network 6. 1-5 is transmitted to the detour control processing unit 4b, and is transmitted to the transmission device 1-4 via the 1-system transmission line L1. Further, data from the transmission device 1-4 to the transmission device 1-3 is transmitted to the 0-system transmission line L0, and the transmission device 1-5 transmits from the detour control processing unit 4b of the transmission device 1-5 via the detour network 6. 1 is transmitted to the detour control processing unit 4a, and is transmitted to the transmission apparatus 1-3 via the 0-system transmission line L0. Therefore, data transmission can be continued using the detour network 6 even when the 0-system and 1-system transmission lines L0 and L1 have a double failure. Also, as described above, the bypass control processing units 4a and 4b receive the information on the reception status of reception / non-receipt due to failure recovery, so that a bypass stop request is sent and each of the transmission / reception control processing units 2-1 to 2-1 2-5 is instructed to return to the normal state, and the connection with the bypass network 6 is released.

  The present invention is not limited to the above-described embodiments, and various additions and modifications can be made. For example, the short-distance information frame period is selected so as not to hinder the actual data transmission rate. . As the information frame format, various known formats can be applied, and a short-range information frame corresponding to the format can be used. In addition, when a failure occurs in the transmission / reception control processing unit, a short-distance information frame cannot be transmitted. Therefore, in the same way as when a transmission path failure occurs, the location where the failure has occurred is recognized, and detour transmission of information frames via the detour network 6 is performed. It can be carried out.

It is explanatory drawing of Example 1 of this invention. It is principal part explanatory drawing of the transmission / reception control processing part of Example 1 of this invention. It is principal part explanatory drawing of the detour control processing part of Example 1 of this invention. It is explanatory drawing of the life value of the short distance information frame of Example 1 of this invention. It is explanatory drawing of the reception status information of Example 1 of this invention. It is a flowchart of the short distance information frame transmission / reception process of the transmission / reception control processing part of Example 1 of this invention. It is a flowchart of the short distance information frame transmission / reception process of the detour control processing part of Example 1 of this invention. It is a one part detailed flowchart in the short distance information frame transmission / reception process of the detour control processing part of Example 1 of this invention. It is explanatory drawing at the time of the 0 system transmission-line failure of Example 1 of this invention. It is explanatory drawing at the time of the transmission line failure of the 0 system of 1 Example of this invention, and 1 system.

Explanation of symbols

1-1 to 1-5 transmission apparatus 2-1 to 2-5 transmission / reception control processing unit 3 terminal control processing unit 4a, 4b detour control processing unit 5 terminal 6 detour network L0, L1 0 system and 1 system transmission path

Claims (6)

In a data transmission system in which a plurality of transmission apparatuses each having a transmission / reception control processing unit for performing transmission / reception control of data by an information frame are sequentially connected in series by duplex transmission lines of 0 system and 1 system,
A detour control processing unit connected to each of the transmission / reception control processing units of one and the other transmission devices located at both ends of the plurality of transmission devices sequentially connected in series by the transmission path,
The detour control processing unit is configured to detect a transmission failure in one or both of the duplex transmission lines of the 0 system and the 1 system, and an information frame scheduled to pass through a transmission failure occurrence location detected by the detection device A data transmission system comprising: means for performing detour transfer control via a detour network.   The bypass control processing unit includes a source address as its own address, a destination address as an address for sequentially specifying the transmission control processing unit corresponding to the plurality of transmission devices, and a life value between the one and the other bypass control processing unit. Means for transmitting a short distance information frame having a value obtained by adding 1 to the number of the transmission / reception control processing units connected to the terminal at a predetermined cycle, and receiving the short distance information frame and having a life value of 1 Means for determining whether the transmission path is normal, no reception even after the lapse of the predetermined period, or the received transmission line abnormality that becomes the life value abnormality, and the transmission / reception control processing unit includes the one detour control process 2. The data transmission system according to claim 1, further comprising means for subtracting 1 from the life value of the short distance information frame transmitted from the unit and transferring it to the other detour control processing unit.   The transmission / reception control processing unit is configured to generate a short-range information frame in which a source address is a self-address, a destination address is a broadcast address, and a life value is a maximum value based on a predetermined number of bits at a predetermined cycle. And a means for receiving a short-range information frame from a transmission / reception control processing unit oppositely connected by the transmission line and transferring a life value of the short-range information frame by decrementing by 1. A configuration for receiving and processing an information frame addressed to its own address on a transmission path showing a larger value by comparing the life values of the short distance information frames received via the transmission lines of the 0 system and the 1 system The data transmission system according to claim 1, further comprising:   The bypass control processing unit between the one and the other connected via the bypass network is opposed to each other via the bypass network when it is determined that the transmission path is abnormal by means for determining whether the transmission path is normal or the transmission path is abnormal. A means for sending a detour request to a connected detour control processing unit and sending an information frame passing through the location determined to be abnormal in the transmission path to a detour control processing unit connected oppositely via the detour network The data transmission system according to claim 1 or 2, wherein Data in which a plurality of transmission devices each having a transmission / reception control processing unit for performing data transmission / reception control are sequentially connected in series via a duplex transmission path of 0-system and 1-system, and data is transmitted between the transmission devices by an information frame In the transmission control method,
From the detour control processing unit respectively connected to the transmission / reception control processing unit of one and the other transmission devices located at both ends of the plurality of transmission devices sequentially connected in series by the transmission path, the source address is obtained at a predetermined cycle. A value obtained by adding 1 to the number of the transmission / reception control processing units connected between the self-address, the destination address for sequentially specifying the plurality of transmission devices, and the life value between the one and the other detour control processing units A process of sending a short-distance information frame in a predetermined cycle;
The detour control processing unit between the one and the other determines whether or not the transmission path is abnormal depending on whether transmission / reception of a short-range information frame is normally performed. Sending a detour request to a detour control processing unit that is oppositely connected via the network, and sending an information frame passing through the transmission line abnormality occurrence location to the detour control processing unit via the detour network. A data transmission control method comprising:   When it is determined that the transmission line abnormality has occurred, the bypass control processing unit bypasses the information frame between the transmission / reception control processing units via the bypass network, and the transmission path is normally received by the short-range information frame. A process of notifying that there is no detour request via the detour network and discarding the information frame of the transmission destination address detoured via the detour network when it is detected that the location where the abnormality has occurred is returned to the normal state 6. The data transmission control method according to claim 5, further comprising:

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