JP4725271B2 - Ring network monitoring method, network device, and ring network system - Google Patents

Description

  The present invention relates to a ring-type network monitoring method, a network device, and a ring-type network system, and more particularly to a technique effective when applied to monitoring a network device redundantly provided in a loop transmission path.

  More specifically, it is configured as a duplex loop consisting of two lines whose data transmission directions are opposite to each other, and consists of a ring topology that transmits simultaneously to two lines and selects and receives from either line when receiving. The present invention relates to a system in which stations are duplicated in a ring network such as a LAN (Local Area Network) and a control network, and the duplicated pair is configured with the same station number.

  As a ring network having a loop transmission line, various networks are known in addition to a token ring and FDDI (Fiber Distributed Data Interface). As described above, in a system in which the transmission right is periodically and periodically circulated by a method such as token circulation, the stations can regularly recognize each other. For example, a station that does not transmit for a certain period of time is considered to have dropped from the ring for some reason. Thereby, the actual configuration information on the ring can be recognized and updated.

  In addition, when adopting a duplex configuration (duplex) consisting of an active station and a standby station in such a network, in general, the station number of the duplex pair station is set to the same station number, and the frame transmitted by the active station is transmitted to another network. Used as a valid frame by the receiving station. There is a known method in which the standby station does not have the transmission right because it is in the standby mode or transmits, but the receiving station identifies the frame transmitted by the standby station and discards it. ing.

  When the network has a duplex configuration, switching between the active system and the standby system in the duplex configuration may occur depending on the demands of network users (applications), system status, and maintenance work. A user or maintenance staff may issue a switching instruction or monitor the configuration from any part of the network by using a command message, etc. At this time, there is a redundant station standby system that can be switched. It is very important to grasp information about whether or not a state is present.

  Here, a method is considered in which the standby station does not have a transmission right, thereby realizing duplication of the same station number. For example, when the transmission bandwidth of each station is scheduled in a time-sharing manner, or when a station having transmission rights is determined by circulating transmission rights (tokens), only the active station among the duplexing stations has the transmission right. The other stations on the receiving side can always handle the received data as operating station data without being aware of whether a certain station is duplexed. Especially in the case of a memory-sharing network where the transmitting station always broadcasts to all stations (broadcast), all the stations secure a receiving memory area for each station, so only the active station transmits. This method is useful for simplifying memory management.

  However, as described above, in the case of the duplexing method of the station where only the active system station transmits, since the standby system does not have the transmission right, a means for confirming the survival of the standby system station is required separately. If the standby station is transmitting, you can check whether the standby station is alive on the system by monitoring the reception of the transmission frame, but if it is not transmitting, use a method other than via the network or the network Another communication path other than the above causes a technical problem that it is necessary to confirm survival.

  In order to avoid this, a specific frame for checking the existence of life is defined, and in addition to the normal data transmission band, a band for checking the existence of the standby system station is provided, and the standby system station communicates there to check the existence. It is also possible to perform this. However, considering the system with a large number of stations as a whole, and the case where most of the stations are duplexed, the bandwidth time for confirmation of survival of the standby system is relatively large compared to the normal transmission bandwidth time. This causes another technical problem that the transmission efficiency of the entire system is reduced.

  In Patent Document 1, a node comprising a CPU and redundant first and second communication units under the control of the CPU is shown as first and second via the first and second communication units, respectively. Each of the first and second communication units connected to each of the transmission paths creates a network subscription list of other nodes recognized in each of the first and second transmission paths and exchanges them with each other. A duplex network system that performs an operation of notifying the network is disclosed.

However, in the technique of Patent Document 1, the above-described technical problem is not recognized, and a specific method for determining whether each of the first and second communication units is healthy with respect to each other. Is not disclosed.
JP 2005-94505 A

  An object of the present invention is to provide a special communication means other than a loop transmission line in a ring network in which an active station and a standby station are redundantly provided on a loop transmission line so that only the active station has a transmission right. It is an object of the present invention to provide a technique capable of confirming the existence and existence of a standby station without requiring a network.

  Another object of the present invention is to provide data transmission efficiency between active stations in a ring network in which an active station and a standby station are redundantly provided on a loop transmission line so that only the active station has a transmission right. It is an object of the present invention to provide a technique capable of confirming the existence and survival of a standby station without lowering.

A first aspect of the present invention is a loop transmission path around which a frame including transmission data and control data accompanying the transmission data circulates;
An active station provided in the loop transmission line;
Corresponding to at least one of the active stations, a standby station provided to make the active station redundant to a redundant station;
A ring network monitoring method including:
A first step in which the active station sends the frame in which the first identification information is set in a part of the control data to the loop transmission line;
The standby system station determines whether or not it has been transmitted from the active system station corresponding to the standby system station with reference to the transmission source station number of the frame passing through the standby system station, and the corresponding operation A second step of rewriting the first identification information of the control data of the frame passing through the standby system station with another second identification information when it is determined that the transmission has been transmitted from the system station ;
The active station determines whether the control data of the frame has been rewritten from the first identification information to the second identification information, and when the control data is rewritten, the duplexing station And / or the third step of recognizing the survival of the standby station constituting the duplexing station,
A ring network monitoring method including

According to a second aspect of the present invention, in the ring network monitoring method according to the first aspect,
The loop transmission line is duplexed into first and second loop transmission lines in which the frame circulates in opposite directions,
In the first step, the same frame is sent from the active station to the first and second loop transmission lines,
In the third step, in the first or second loop transmission path in which the frame is transmitted in the direction from the active station of the duplex station to the standby station through the shortest path, the downstream of the standby station By determining whether or not all the active stations other than the duplexing station located on the side have rewritten the control data of the frame passing through the own station with the second identification information, And / or a ring network monitoring method for recognizing the survival of the standby station constituting the duplexing station.

According to a third aspect of the present invention, in the ring network monitoring method according to the first aspect,
The loop transmission line is duplexed into first and second loop transmission lines in which the frame circulates in opposite directions,
In the first step, the same frame is sent from the active station to the first and second loop transmission lines,
In the third step, the active station of the duplex station transmits the frame in the direction from the standby station of the duplex station to the active station in the shortest path. By determining whether or not the control data of the frame coming from the standby station via the transmission path has been rewritten to the second identification information, the existence of the standby station and / or the standby system A ring network monitoring method for recognizing the existence of a station is provided.

  According to a fourth aspect of the present invention, there is provided the ring network monitoring method according to the first aspect, wherein the control data is a start delimiter for identifying a head of the frame. .

According to a fifth aspect of the present invention, there is provided a loop-shaped transmission line composed of two lines whose frame transmission directions are opposite to each other, a duplex station including an active station and a standby station assigned the same station number, A method of controlling a ring network system in which the frame is simultaneously transmitted to the two lines, and one of the lines is selected at the time of reception to receive the frame;
Two types of frame identifiers included in the frame are properly used, and when the frame transmitted by the active station passes through the standby station, the standby station refers to the transmission source station number of the frame and the standby station And the frame identifier is rewritten when it is determined that it is transmitted from the corresponding active station, and the active station Provided is a ring network monitoring method for recognizing the existence of a standby station and / or monitoring its operation based on whether or not an identifier is rewritten.

A sixth aspect of the present invention is a network device functioning as an active station and / or a standby station provided redundantly in a loop transmission path through which a frame including transmission data and control data accompanying the transmission data flows. There,
When functioning as the standby station, it is determined whether or not the frame is transmitted from the active station corresponding to the standby station by referring to the transmission source station number of the frame passing through the standby station. When it is determined that the frame is transmitted from the corresponding active station, an operation of rewriting a part of the control data of the frame is performed, and when functioning as the active station, the frame is transferred to the loop. An operation for sending to the transmission line, and an operation for determining the presence and / or soundness of the standby station based on whether or not the control data of the frame received from the loop transmission line has been rewritten. Control logic means for performing
And a storage unit that stores the determination result of the presence and / or soundness of the standby station.

  According to a seventh aspect of the present invention, there is provided the network device according to the sixth aspect, wherein the control data is a start delimiter for identifying a head of the frame.

An eighth aspect of the present invention is a loop transmission path through which a frame including transmission data and control data accompanying the transmission data flows,
A network device that is redundantly provided in the loop transmission line and functions as an active station and / or a standby station;
A ring network system including
Each said network device is
When functioning as the standby station, it is determined whether or not the frame is transmitted from the active station corresponding to the standby station by referring to the transmission source station number of the frame passing through the standby station. When it is determined that the frame is transmitted from the corresponding active station, an operation of rewriting a part of the control data of the frame is performed, and when functioning as the active station, the frame is transferred to the loop. An operation for sending to the transmission line, and an operation for determining the presence and / or soundness of the standby station based on whether or not the control data of the frame received from the loop transmission line has been rewritten. Control logic means for performing
There is provided a ring network system including storage means for storing a determination result of the presence and / or health of the standby station.

  According to a ninth aspect of the present invention, there is provided the ring network system according to the eighth aspect, wherein the control data is a start delimiter for identifying a head of the frame.

For example, in the ring network system of the present invention, only the active station performs frame transmission either actively or passively. The standby station can receive the frame of the other station and the active station having the same station number as the own station, but does not transmit. Since it is a loop type network, each station repeats frame reception and relay transmission to transmit the frame in a ring shape, and the transmission source station removes the frame (circulation return frame) transmitted by itself. The network is configured as a duplex loop composed of two lines whose transmission directions are opposite to each other, and each node has a function of simultaneously transmitting to two lines at the time of transmission and selecting one of the lines at the time of reception and performing reception.
An active station having a transmission right transmits a frame, and each station sequentially relays the frame. At this time, when a standby station that has received a frame having the same transmission source station number as its own station relays the frame, it rewrites control data such as a frame start identifier (start delimiter) to another type and relays the frame. .

  Each receiving station and transmission source active station receives and detects a frame with the start delimiter rewritten from one of the two lines, so that the transmission source station of the frame is duplicated and is a duplexed pair. It is possible to recognize that the standby station is alive.

  According to the above-described present invention, for example, a part of the control data such as the frame identifier other than the transmission data constituting the frame used in the normal communication between the active stations is transferred to the standby system that does not have the right to transmit the frame. The station rewrites with specific identification information when the frame passes through its own station, and the active station or other active station that is the transmission source of the frame determines whether the standby station exists and Since the survival state of the standby station is determined, it is not necessary to provide a communication means for confirming the survival of the standby station other than the original loop transmission line.

  Furthermore, since the portion of the control data not related to the transmission data is used in the frame used for communication of the original transmission data between the active stations, the data transmission efficiency of the original communication between the active stations is reduced. Nor.

  According to the present invention, in a ring network in which an active station and a standby station are redundantly provided on a loop transmission line, and only the active station has a transmission right, special communication means other than the loop transmission line are provided. It is possible to confirm the existence and survival of the standby station without the need for

  In addition, in a ring network in which an active station and a standby station are provided redundantly on a loop transmission line so that only the active station has a transmission right, without reducing the data transmission efficiency between the active stations, It is possible to confirm the existence and survival of the standby station.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a conceptual diagram showing an example of the configuration of a frame used in a ring network system according to an embodiment of the present invention. FIG. 2 is a diagram of the ring network system according to an embodiment of the present invention. FIG. 3 is a block diagram showing an example of the configuration of a network apparatus constituting the ring network system of the present embodiment, and FIG. 4 is an operation of the ring network system of the present embodiment. FIG. 5 is a flowchart showing an example of the operation of the ring network system according to the present embodiment.

  As illustrated in FIG. 2, the ring network system according to the present embodiment includes a loop transmission line 20 and a plurality of network devices connected to the loop transmission line 20 and each constituting a station. 10 is included.

The loop transmission line 20 is duplexed into two loops, a clockwise A system loop 21 and a counterclockwise B system loop 22.
In the case of the present embodiment, a single configuration station 0 and a single configuration station 2 that are not made redundant, a duplex configuration station 1 and a duplex configuration that are each made redundant, are provided on the loop transmission line 20. Station 3 is located.

  The redundant configuration station 1 is made redundant by being composed of an active system station 1-a and a standby system station 1-b having the same functions. Similarly, the redundant configuration station 3 is an active system having the same functions. Redundancy is achieved by comprising the station 3-a and the standby station 3-b.

Therefore, there are a total of six stations on the loop transmission line 20, and each of the six stations is constituted by the network device 10.
The same station number is assigned to the active system station 1-a and the standby system station 1-b constituting the duplex configuration station 1, and the other single configuration station 0, single configuration station 2, and duplex configuration station 3 Recognized as one duplex configuration station 1.

  Similarly, the same station number is assigned to the active system station 3-a and the standby system station 3-b constituting the duplex configuration station 3, and from the other single configuration station 0, the single configuration station 2, and the duplex configuration station 1 It is recognized as one duplex configuration station 3.

  In the case of the present embodiment, each station other than the standby station constituting the duplex configuration station receives and holds one token frame (hereinafter referred to as a token) (not shown) that circulates in the loop transmission path 20, for example. Acquire the transmission right, execute transmission of the frame 40, and release (transmit) the token to the loop transmission path 20 when the transmitted frame 40 goes around the loop transmission path 20 and returns to the local station. The transfer right is transferred to another station.

  Alternatively, as a method for transmitting and receiving transmission rights between stations other than the standby station constituting the duplex configuration station, each station actively recognizes a time slot (time slot) that the own station should transmit in the entire band time. A method of avoiding duplication of the transmission of the frame 40 between the stations by acquiring the transmission right and executing the transmission of the frame 40 may be used.

  Thus, in the case of the present embodiment, the standby station constituting the duplex configuration station does not have the right to transmit the frame 40, but as will be described later, the reference of the passing frame 40 and the update of some control information are performed. Is possible.

  As illustrated in FIG. 3, the network device 10 constituting each station includes, as an example, a frame processing unit 11, a control memory 12, an A-system reception buffer 13, an A-system transmission buffer 14, a B-system reception buffer 15, and A B-system transmission buffer 16 is included.

  In addition, the network device 10 is connected to an external information processing device 30, and in response to a request for transmission / reception of information from the information processing device 30, a loop transmission path 20 is connected to another network device 10 (station). Information communication is executed.

  The frame processing unit 11 transmits the transmission data received from the network device 10 to another station on a frame 40 as will be described later, or extracts the transmission data from the frame 40 received from another station to process the data. Processing to be transmitted to 30 is performed.

  Furthermore, in the case of the present embodiment, the frame processing unit 11 performs processing illustrated in the flowchart of FIG. 5 to be described later, so that presence / absence of redundant duplex configuration stations exists and duplex configuration stations Is provided with a control logic means 11a for executing the existence confirmation of the standby system station constituting.

The control memory 12 stores various control information required when the frame processing unit 11 processes the frame 40.
As information related to the present embodiment, the local memory station number information 12a, operation / standby identification information 12b, standby system state information 12c, default delimiter code 12d, rewrite delimiter code 12e, and other station information 12f are stored in the control memory 12. Is stored.

  The own station number information 12a stores the station number assigned to the own station. In this case, in the redundant configuration station 1, the same station number is set for the active station 1-a and the standby station 1-b. The same applies to the other redundant configuration stations 3.

  The operation / standby identification information 12b is used to identify whether or not the own station constitutes a duplex configuration station and, when configuring the duplex configuration station, whether the own station is an active station or a standby station. Information is stored.

The standby system status information 12c stores information for identifying the survival status of the corresponding standby system station when the duplexed configuration station is configured and the own station functions as an active system station.
The default delimiter code 12d stores identification information (in this case, “JK” described later) set by the active station as a start delimiter 41 that configures a frame 40 described later.

  The rewriting delimiter code 12e stores identification information (in this case, “JJ”, which will be described later) used when the standby station rewrites a start delimiter 41 constituting the frame 40 which will be described later.

  The other station information 12f is information of other stations whose existence has been recognized on the loop transmission line 20, and there are as many as the number of recognized other stations. The individual other station information 12f includes a station number 12f-1 of the other station, a duplex presence / absence 12f-2 indicating whether or not the other station is a duplex configuration station, and a standby system when the other station is a duplex configuration station. The information of the standby system state 12f-3 indicating the survival state of the station is included.

The A-system reception buffer 13 (B-system reception buffer 15) receives the frame 40 coming from the upstream side of the A-system loop 21 (B-system loop 22).
The A system transmission buffer 14 (B system transmission buffer 16) transmits the frame 40 to the downstream side of the A system loop 21 (B system loop 22).

  The frame processing unit 11 discriminates the frame 40 that has arrived at the A-system reception buffer 13 (B-system reception buffer 15) of the A-system loop 21 (B-system loop 22), and after performing necessary processing, The frame 40 is discarded if it is a single station or an operating station of a duplex configuration station and the transmission source of the frame 40, otherwise the A-system transmission buffer 14 (B-system transmission buffer 16 ) To A system loop 21 (B system loop 22).

  In the case of the present embodiment, the control logic means 11a is such that the own station is a standby station of the duplex configuration station and the transmission source of the frame 40 received from the A system loop 21 (B system loop 22) is If it is an active system station of the duplicated configuration station to which it belongs, the start delimiter 41 of the frame 40 is rewritten as described later, and a process of retransmitting to the A system loop 21 (B system loop 22) is performed.

  As illustrated in FIG. 1, the frame 40 used in the ring network system according to the present embodiment includes a start delimiter 41, a frame header 42, transmission data 43, a frame check code 44, and an end delimiter 45. .

The start delimiter 41 is information for identifying the head of the frame 40.
The frame header 42 includes information such as a transmission source station number indicating the transmission source station of the frame 40 and a destination station.

The transmission data 43 is net transmission data carried by the frame 40.
The frame check code 44 stores information such as an error check code used when detecting or correcting an error during transmission of the frame 40 on the receiving side.

The end delimiter 45 stores information for identifying the end of the frame 40.
In the case of the present embodiment, the start delimiter 41 uses a 4 bit-5 bit code conversion method as an example, and the code of the start delimiter 41 added when the operating system station transmits the frame 40 is “JK”, and the standby system station. When the start delimiter 41 is rewritten when the frame 40 having the station number of the duplex configuration station of the same group as the transmission source station number is relayed, “JJ” is used as the code of the start delimiter 41.

Hereinafter, an example of the operation of the ring network system according to the present embodiment will be described.
Each station relays the frame 40 received from the loop transmission path 20 and simultaneously captures it as received data. The transmission right circulates in the order of single constituent station 0 → active station 1-a → single constituent station 2 → active station 3-a. The standby system station 1-b and the standby system station 3-b have no transmission right, but in order to transmit the survival of the own station to other stations, the active system station 1-a or the active system corresponding to the own station The station 3-a rewrites the start delimiter 41 as described later when the transmission source frame 40 passes through its own station.

  FIG. 4 shows how the frame 40 (frame F1-a) transmitted by the active station 1-a of the duplexing configuration station 1 is processed while circulating around the loop transmission line 20. When transmitting the frame 40, the frame processing unit 11 of the active station 1-a uses the default delimiter code 12d (in this case, “JK”) set in the control memory 12 as the start delimiter 41.

  The frame F1-a (JK) with the start delimiter 41 “JJ” transmitted from the active station 1-a, the frame with the start delimiter 41 “JJ” from the standby station 1-b belonging to the same redundant configuration station 1, Rewrite to F1-a (JJ). That is, the standby station 1-b rewrites the start delimiter 41 from “JK” to “JJ” when the transmission source station number set in the frame header 42 of the received frame 40 is the same as that of the own station.

  Even if the start delimiter 41 is rewritten, the data portion (transmission data 43) of the frame 40 is not affected, and each station relays and transfers the received frame from upstream to downstream while receiving the frame 40. The frame that has returned around the loop transmission path 20 is deleted at the transmission source station, and the transmission right passes to the next station. In transmission, the same frame 40 is always transmitted to both the A-system loop 21 and the B-system loop 22 at the same time, and the receiving station receives from both systems and selects one of them to capture.

  In FIG. 4, the frame F1-a (JK) transmitted from the active station 1-a flows in the direction of the active station 1-a → the single constituent station 0 → the standby station 3-b in the A loop 21. When it finally passes through the standby system station 1-b, it is rewritten to the frame F1-a (JJ) and returns to the active system station 1-a.

  In the B loop 22, the frame 40 flows in the direction from the active station 1-a to the standby station 1-b to the single constituent station 2, and when passing through the standby station 1-b, the frame F1-a. It is rewritten as (JJ) and relayed to the single configuration station 2 → the duplex configuration station 3 and the single configuration station 0, and finally returns to the active station 1-a. For this reason, in each of the single constituent station 2, the redundant constituent station 3, and the single constituent station 0 other than the source redundant constituent station 1, the frame F1-a (having the start delimiter 41 rewritten by the standby station 1-b ( JJ) confirms that the start delimiter 41 has been rewritten to “JJ” when passing through its own station via the B-system loop 22, so that the source of the frame F1-a (JJ) It is possible to simultaneously recognize that the station number duplex configuration station 1 has the duplex configuration and that the standby station 1-b is healthy.

In this way, each station receives and relays the frame 40 transmitted from either the A-system loop 21 or the B-system loop 22 with the start delimiter 41 rewritten to “JJ”.
Therefore, each station other than the redundant configuration station 1 (active station 1-a) that is the transmission source of the frame 40 has the start delimiter 41 rewritten in the frame 40 (frame F1-a) that passes through its own station. It can be recognized that the transmission source station of the frame 40 has a duplex configuration and that both the active station and the standby station are healthy.

  In the case of the present embodiment, in each station, the “transmission source station number that transmitted the frame 40 with the rewritten start delimiter 41” is stored in the station number 12f-1 of the other station information 12f, and the corresponding duplexing presence / absence 12f− 2 is stored as a redundant configuration station.

  Further, the control logic means 11a monitors whether or not the start delimiter 41 has been rewritten in the standby station for a station in which information indicating that it is a duplex configuration station is already set in the duplex presence / absence 12f-2. Thus, it is determined whether or not the standby station is alive.

  That is, if the start delimiter 41 is rewritten by the standby system station after being stored as a redundant configuration station once in the duplex presence / absence 12f-2, the standby system station is sound and the standby system station starts. When the delimiter 41 is not rewritten, the standby station can be recognized as a failure.

  As a result, which station is duplicated as a duplicated configuration station on the ring network system, and if it is duplicated, a standby station that does not have transmission rights (does not transmit) survives. It can be monitored whether or not.

  That is, in the case of FIG. 4, if the B-system loop 22 is healthy, the single constituent station 2 through which the frame F1-a (JJ) transmitted from the active system station 1-a and rewritten by the standby system station 1-b passes. The redundant constituent station 3 and the single constituent station 0 check whether or not the frame F1-a (JJ) is rewritten, thereby determining whether the redundant constituent station 1 including the standby station 1-b exists and the standby system The presence or absence of the soundness of the station 1-b can be recognized.

  Further, in the redundant configuration station, if it is limited to the active system station that is the transmission source of the frame 40, even if either the A system loop 21 or the B system loop 22 is disconnected, the local station returns to the transmission source. By monitoring the frame, it is possible to confirm the survival of the standby station that is the duplex pair of the own station.

The operation of each station of the above-described embodiment will be described with reference to the flowchart of FIG.
First, when the frame 40 is received from the A-system loop 21 or the B-system loop 22 (step 101), it is checked against the local station number information 12a whether or not the transmission source station number of the frame header 42 of the frame 40 is that of the local station. (Step 102).

  When the transmission source is the local station, the operation / standby identification information 12b is further referred to to determine whether the local station is a duplex configuration station (step 103). The frame 40 transmitted by the own station and circulated is discarded (step 109), and the transmission right is released to the downstream station (step 110).

  On the other hand, if it is determined in step 103 that the local station is a redundant configuration station, it is further determined by the operating / standby identification information 12b whether the local station is an active system station or a standby system station (step 103). In the case of a station, the active station of its own station rewrites the start delimiter 41 of the transmission source frame 40 with the rewrite delimiter code 12e (step 105), and relays and transmits the rewritten frame 40 downstream ( Step 106).

  If it is determined in step 104 above that the local station is an active station, it is determined whether or not the start delimiter 41 of the frame 40 transmitted by the local station has been rewritten (step 107). If so, it is determined that its own standby system is healthy, and the determination result is recorded in the standby system status information 12c (step 108). On the other hand, if it is determined in step 107 that it has not been rewritten, it is assumed that there is some trouble in the standby station of the own station, and information on the failure is recorded in the standby state information 12c (step 111). .

  After recording the standby system state information 12c in step 108 or 111, the received frame 40 is discarded (step 109), and the transmission right is transferred to another station by releasing the transmission right (step 110).

  When it is determined that the transmission source of the frame 40 received in step 102 is not the local station, it is determined whether or not the destination station number of the frame header 42 is that of the local station (step 112). In this case, after checking whether the start delimiter 41 is rewritten or not, the other station duplex state or the standby station state is confirmed and recorded in the corresponding other station information 12f (step 114). Relay transmission is performed downstream (step 115).

  If it is determined in step 112 that it is addressed to the own station, the transmission data 43 is fetched from the frame 40 and sent to the information processing apparatus 30 (step 113). After the start delimiter is checked (step 114), the frame 40 is Relay transmission is performed downstream (step 115).

  As described above, according to the present embodiment, the line is duplexed by the loop transmission line 20 composed of the two lines of the A system loop 21 and the B system loop 22 whose transmission directions are opposite to each other, including duplex and non-duplex. Ring network in which only the active system stations (single configuration station 0, single configuration station 2, active system station 1-a, active system station 3-a) have the right to transmit frame 40 and exchange data with each other. Therefore, it is possible to confirm the survival of standby stations such as the standby station 1-b and the standby station 3-b that do not have the transmission right of the frame 40 without reducing the data transmission efficiency of the active station.

  Further, when the two lines of the A-system loop 21 and the B-system loop 22 are in a healthy state, it is grasped whether or not each station in the ring network system including the own station has a duplex configuration in all stations. Can do.

  Even if a failure occurs in one of the two lines of the A-system loop 21 and the B-system loop 22, the active system station of the redundant configuration station waits for a redundant pair having the same station number as the own station. The survival of the affiliated station can be confirmed.

  As a result, the system configuration in the ring network system can be grasped without lowering the transmission efficiency of the frame 40 in the loop transmission line 20, system maintenance is facilitated, system management is facilitated, and preventive maintenance is improved. Therefore, further improvement in reliability can be realized.

It is a conceptual diagram which shows an example of a structure of the flame | frame used with the ring type network system which is one embodiment of this invention. It is a conceptual diagram which shows an example of a structure of the ring type network system which is one embodiment of this invention. It is a block diagram which shows an example of a structure of the network apparatus which comprises the ring type network system which is one embodiment of this invention. It is a conceptual diagram which shows an example of an effect | action of the ring type network system which is one embodiment of this invention. It is a flowchart which shows an example of an effect | action of the ring type network system which is one embodiment of this invention.

Explanation of symbols

0 Single configuration station 1 Redundant configuration station 1-a Active system station 1-b Standby system station 2 Single configuration station 3 Redundant configuration station 3-a Active system station 3-b Standby system station 10 Network device 11 Frame processing unit 11a Control logic Means 12 Control memory 12a Local station number information 12b Operation / standby identification information 12c Standby system state information 12d Default delimiter code 12e Rewrite delimiter code 12f Other station information 12f-1 Station number 12f-2 Duplex presence / absence 12f-3 Standby system state 13A System reception buffer 14 System A transmission buffer 15 System B reception buffer 16 System B transmission buffer 20 Loop transmission path 21 System A loop 22 System B loop 30 Information processing device 40 Frame 41 Start delimiter 42 Frame header 43 Transmission data 44 Frame check code 45 End delimiter

Claims (9)

A loop transmission path around which a frame including transmission data and control data accompanying the transmission data circulates;
An active station provided in the loop transmission line;
Corresponding to at least one of the active stations, a standby station provided to make the active station redundant to a redundant station;
A ring network monitoring method including:
A first step in which the active station sends the frame in which the first identification information is set in a part of the control data to the loop transmission line;
The standby system station determines whether or not it has been transmitted from the active system station corresponding to the standby system station with reference to the transmission source station number of the frame passing through the standby system station, and the corresponding operation A second step of rewriting the first identification information of the control data of the frame passing through the standby system station with another second identification information when it is determined that the transmission has been transmitted from the system station ;
The active station determines whether the control data of the frame has been rewritten from the first identification information to the second identification information, and when the control data is rewritten, the duplexing station And / or the third step of recognizing the survival of the standby station constituting the duplexing station,
A ring network monitoring method comprising: The ring network monitoring method according to claim 1,
The loop transmission line is duplexed into first and second loop transmission lines in which the frame circulates in opposite directions,
In the first step, the same frame is sent from the active station to the first and second loop transmission lines,
In the third step, in the first or second loop transmission path in which the frame is transmitted in the direction from the active station of the duplex station to the standby station through the shortest path, the downstream of the standby station By determining whether or not all the active stations other than the duplexing station located on the side have rewritten the control data of the frame passing through the own station with the second identification information, And / or the survival of the standby station constituting the duplexing station is recognized. The ring network monitoring method according to claim 1,
The loop transmission line is duplexed into first and second loop transmission lines in which the frame circulates in opposite directions,
In the first step, the same frame is sent from the active station to the first and second loop transmission lines,
In the third step, the active station of the duplex station transmits the frame in the direction from the standby station of the duplex station to the active station in the shortest path. By determining whether or not the control data of the frame coming from the standby station via the transmission path has been rewritten to the second identification information, the existence of the standby station and / or the standby system A ring network monitoring method characterized by recognizing the existence of a station.   2. The ring network monitoring method according to claim 1, wherein the control data is a start delimiter for identifying a head of the frame. A loop transmission path composed of two lines whose frame transmission directions are opposite to each other, and a duplex station including an active station and a standby station assigned the same station number, and simultaneously transmitting the frame to the two lines And a ring network system control method for receiving the frame by selecting one of the lines at the time of reception,
Two types of frame identifiers included in the frame are properly used, and when the frame transmitted by the active station passes through the standby station, the standby station refers to the transmission source station number of the frame and the standby station And the frame identifier is rewritten when it is determined that it is transmitted from the corresponding active station, and the active station A ring network monitoring method, characterized in that the presence recognition and / or operation monitoring of the standby station is performed based on whether or not the identifier is rewritten. A network device functioning as an active station and / or a standby station provided redundantly in a loop transmission path through which a frame including transmission data and control data accompanying the transmission data flows,
When functioning as the standby station, it is determined whether or not the frame is transmitted from the active station corresponding to the standby station by referring to the transmission source station number of the frame passing through the standby station. When it is determined that the frame is transmitted from the corresponding active station, an operation of rewriting a part of the control data of the frame is performed, and when functioning as the active station, the frame is transferred to the loop. An operation for sending to the transmission line, and an operation for determining the presence and / or soundness of the standby station based on whether or not the control data of the frame received from the loop transmission line has been rewritten. Control logic means for performing
Storage means for storing a determination result of the presence and / or soundness of the standby station;
A network apparatus comprising:   7. The network device according to claim 6, wherein the control data is a start delimiter for identifying a head of the frame. A loop transmission path through which a frame including transmission data and control data accompanying the transmission data flows;
A network device that is redundantly provided in the loop transmission line and functions as an active station and / or a standby station;
A ring network system including
Each said network device is
When functioning as the standby station, it is determined whether or not the frame is transmitted from the active station corresponding to the standby station by referring to the transmission source station number of the frame passing through the standby station. When it is determined that the frame is transmitted from the corresponding active station, an operation of rewriting a part of the control data of the frame is performed, and when functioning as the active station, the frame is transferred to the loop. An operation for sending to the transmission line, and an operation for determining the presence and / or soundness of the standby station based on whether or not the control data of the frame received from the loop transmission line has been rewritten. Control logic means for performing
Storage means for storing a determination result of the presence and / or soundness of the standby station;
A ring network system characterized by including:   9. The ring network system according to claim 8, wherein the control data is a start delimiter for identifying a head of the frame.

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