JP4641188B2 - Redundant LAN system - Google Patents

Description

The present invention relates to an information processing system configured by connecting a large number of devices including a duplexed device to each other via a duplexed LAN, and in particular, operation by rationally switching the operational status of the duplexed LAN. The present invention relates to a redundant LAN system that continues the above.
In a monitoring control system such as a water management system or a dam management system, a large number of devices equipped with sensors are connected via a redundant LAN in order to reliably observe various events at all times.

  Such a monitoring control system is required to be able to perform maintenance work including work such as device testing while continuing operation as a system.

FIG. 14 shows a configuration example of a general monitoring control system.
In the monitoring control system illustrated in FIG. 14, m types of monitoring apparatuses 401 _{10 to} 401 _m1 that are duplicated are connected to each other via a LAN 402. In FIG. 14, the subscript attached to the reference numeral indicating the monitoring device indicates the type of the monitoring target and the system to which it belongs (“0” system or “1” system).

In such a monitoring and control system, for example, to set the operation mode or the non-operational mode to the monitor ₄₀₁ 10 to 401 _m1, the operation in the header of the packet that each of these monitoring devices ₄₀₁ 10 to 401 _m1 is sent to LAN402 Embed identification information indicating the mode.
As a result, it is possible to distinguish whether the data flowing through the single LAN 402 is data related to the operation of the monitoring control system or the data in the non-operating state, so that the operation of the monitoring control system can be continued. Maintenance work including testing of each monitoring device can be realized.

As described above, the configuration for connecting the duplex devices via the LAN is widely used in the field of communication processing systems and the like (see Patent Document 1).
In addition, in order to simultaneously flow different types of data, a system in which each device is connected using two LANs has been proposed.
For example, each device shown in FIG. 15 is connected to two LANs 403 and 404 using two ports provided for each, and performs main data communication via the LAN 403 according to UDP (User Datagram Protocol). Control information and the like are exchanged via the LAN 404 in accordance with TCP (Transmission Control Protocol).

Of course, in the supervisory control system shown in FIG. 14, the reliability of the system can be improved by further duplicating the LAN.
For example, as shown in FIG. 16, to connect the monitoring device ₄₀₁ 10 to 401 _m0 "0" based on the LAN402 _0, whereas, connect "1" system of the monitoring device ₄₀₁ 11 to 401 _m1 to LAN402 _1, The operation / non-operation system switching related to the monitoring device and the operation system / non-operation system switching related to the LAN are linked.

Thus, for example, when a failure such as LAN402 ₀ to cable disconnection of the active occurs, instead switch to "1" based LAN402 ₁ and "1" based monitoring device ₄₀₁ 11 to 401 _m1 operating system of Thus, the operation of the supervisory control system can be maintained.
Japanese Patent Laid-Open No. 4-037346

In the operation state switching method applied to the monitoring control system described above, an abnormality of a device belonging to an operating system or an abnormality of a LAN is regarded as an equivalent trigger for switching the operation state individually.
For this reason, for example, if a failure such as a cable disconnection occurs in the active LAN, regardless of whether there is an abnormality in the monitoring device connected to the LAN corresponding to the other system, Switching is executed. Therefore, if there is an abnormality in the monitoring device belonging to the non-operating system, the entire monitoring control system may be stopped due to the abnormality of the monitoring device after switching.

In other words, in the operation status switching method applied in the conventional supervisory control system, it is reasonable to determine which system should be the active system when multiple failures occur in both the active system and the non-active system. Could not be judged.
SUMMARY OF THE INVENTION An object of the present invention is to provide a duplex LAN system capable of discriminating a system advantageous for continuation of operation individually and reliably for an apparatus system and a LAN and reflecting it in switching of an operation state.

The first duplex LAN system according to the present invention comprises transmission path forming means, status information collecting means, risk evaluating means, and path switching means.
The principle of the first redundant LAN system according to the present invention is as follows.
In a duplexed LAN system configured by physically connecting a plurality of devices including at least one set of duplexed devices to each of two LANs, the transmission path forming means includes each of the plurality of devices, two LANs, and By using the physical connection, two systems of logical transmission paths are formed from logical paths logically set between a plurality of devices via two LANs. The status information collection unit collects communication status information indicating the communication status for all logical paths set in the two LANs. The path switching means is configured to select one of the two logical transmission paths based on the number of devices involved in each of the two logical transmission paths based on the communication status information collected by the status information collecting means. Is switched to the transmission path by notifying a plurality of apparatuses that the transmission path is used for transmission of operational data in the duplex LAN system.

The operation of the first redundant LAN system configured as described above is as follows.
With the transmission path forming means, two systems of logical transmission paths, that is, two systems of virtual LANs, are formed from logical paths logically set between a plurality of devices via two LANs. Through these virtual LANs, for example, communication state information indicating communication states represented by whether or not communication is possible is collected for all logical paths by the state information collection unit. The communication state information collected in this way includes an index indicating the degree to which all logical paths are suitable for transmission of operational data . Based on the number of devices involved in each of the abnormalities of the two logical transmission paths reflected in the result of aggregation of this communication status information by a statistical method, either virtual LAN is operated as data. The route switching means broadcasts to all devices that it will be used for transmission. Thereby, for example, a virtual LAN with a small number of devices involved in an abnormality can be used for transmission of operational data.

The second duplex LAN system according to the present invention includes transmission path forming means, status information collecting means, risk evaluation means, and path switching means, and the risk evaluation means includes calculation means.
The principle of the second redundant LAN system according to the present invention is as follows.
In a duplexed LAN system configured by physically connecting a plurality of devices including at least one set of duplexed devices to each of two LANs, the transmission path forming means includes each of the plurality of devices and the two LANs. Two logical transmission paths are formed from logical paths logically set between the plurality of devices via the two LANs. The status information collection unit collects communication status information indicating the communication status for all logical paths set in the two LANs. The risk evaluation means evaluates the operation risk for each of the two logical transmission paths based on the communication state information. The path switching means is based on the result of the evaluation by the risk evaluation means, so that one of the two logical transmission paths is a transmission path used for transmission of operational data in the redundant LAN system. The transmission path is switched by reporting the information. Then, the calculation means provided in the risk evaluation means performs a logical sum operation on the state determination value related to each device included in the communication status information, and whether each of the devices is involved in a communication state abnormality. It is output as an abnormal addition value indicating whether or not.

The operation of the second redundant LAN system configured as described above is as follows.
With the transmission path forming means, two systems of logical transmission paths, that is, two systems of virtual LANs, are formed from logical paths logically set between a plurality of devices via two LANs. Through these virtual LANs, for example, communication state information indicating communication states represented by whether or not communication is possible is collected for all logical paths by the state information collection unit. The communication state information collected in this way includes an index indicating the degree to which all logical paths are suitable for transmission of operational data. The calculation means of the risk evaluation means performs a logical sum operation on the state determination value related to each device included in the communication state information, and obtains an abnormal addition value indicating whether or not each device is involved in a communication state abnormality. The risk evaluation means can rationally evaluate the risk when each of the virtual LANs of each system is used as a transmission path for operation data, based on the abnormal addition value. Then, the path switching means notifies all devices of the switching to the virtual LAN of the system whose risk is low based on the evaluation result, so that the virtual LAN with a lower risk can be changed to the active system. It can be used as a LAN.

The third redundant LAN system according to the present invention is configured by further including a totalizing means in addition to the risk evaluation means provided in the second redundant LAN system described above .
The principle of the third redundant LAN system according to the present invention is as follows.
In the risk evaluation means provided in the first redundant LAN system described above , the summation means sums up the abnormal addition values obtained corresponding to each device by the arithmetic means for each of the two logical transmission paths. The sum of the added values is output as the operational risk for each of the two logical transmission paths.

The operation of the third redundant LAN system configured as described above is as follows.
For the devices that are said to be involved in the communication state abnormality by the computing means, each given abnormal addition value, and by summing the abnormality addition value for each of the two logical transmission paths, An evaluation value indicating an operation risk corresponding to the number of devices involved in an abnormal communication state can be obtained for each logical transmission path by extremely simple arithmetic processing.

The operational risk obtained in this way objectively indicates how much the communication state in the logical transmission path of each system has deteriorated. Therefore, by passing such operational risk to the path switching means as an index for determining the necessity of switching, a transmission path with a better communication state in a system in which a large number of devices are connected via a duplicated LAN. Can be selected as the operational system.

A fourth redundant LAN system according to the present invention includes a status information collecting means provided in any one of the first to third redundant LAN systems described above, a diagnostic message sending means, a determining means, an information accumulating means, And a response means and an extraction means.
The principle of the fourth redundant LAN system according to the present invention is as follows.
In the status information collecting means provided in any one of the first to third redundant LAN systems described above, the diagnostic message sending means is provided in the plurality of devices and is physically connected via at least one LAN. A diagnostic message is sent to all devices. The determination unit is provided in the plurality of devices, and determines whether normal data transmission is possible via a logical path to the destination device based on the presence / absence of a response message for the diagnostic message. The information accumulating means is provided in the plurality of devices, and accumulates state determination values indicating the determination results obtained by the determination means corresponding to the respective logical paths. The response means is provided for the logical paths belonging to each of the two logical transmission paths in response to the reception of the diagnostic message from the devices that are provided in the plurality of devices and are physically connected via both LANs. A response message including communication state information including collected state determination values is returned to the information accumulation unit. The extraction unit is provided in the plurality of devices, extracts communication state information included in the received response message, and provides the information to the accumulation process.
The operation of the fourth redundant LAN system configured as described above is as follows.
A diagnostic message is sent to all devices other than the own device by the diagnostic message sending means provided in the plurality of devices, and in response to reception of these diagnostic messages, the response message provided in each device A response message including the communication state information accumulated by the information accumulation means is returned. In response to the reception of the response message, the determination means provided in each device determines the communication state of the logical path with the device that is the source of the response message, and is included in the response message. The communication status information is extracted and collected together in the information accumulation means. Therefore, when the transmission / reception of the diagnostic message and the response message as described above is completed, the communication state information including the state determination values related to all the logical paths constituting the above-described two virtual LANs is collected in all devices. Has been. Therefore, even if an abnormality occurs in an arbitrary logical path that constitutes one virtual LAN, both devices connected by this logical path can receive diagnostic messages sent and received via the other virtual LAN. Collecting communication status information including status judgment values related to devices facing each other via a logical path in which an error has occurred, using a response message or a response message including communication status information collected by another device Can do.
A fifth duplex LAN system according to the present invention is configured by including, in the information accumulation means provided in the above-described fourth duplex LAN system, weight holding means, correction means, and state determination value storage means. .
The principle of the fifth redundant LAN system according to the present invention is as follows.
In the information accumulation means provided in the fourth redundant LAN system described above, the weight holding means is a weight indicating the importance of the role of the logical path in the redundant LAN system for all logical paths set in the redundant LAN system. Hold. The correcting unit corrects the state determination value indicating the determination result corresponding to each logical path obtained by the determining unit based on the corresponding weight held in the weight holding unit. The state determination value storage means holds the corrected state determination value corresponding to each logical path .

The operation of the fifth redundant LAN system configured as described above is as follows.
For example, it is clear that a logical path set between redundant devices and a logical path where operational data is actually flowing in a redundant LAN system or a logical path that can be a transmission path for operational data by switching virtual LANs. There is a difference in the degree of importance, and such a difference can be assumed at the stage of constructing the dual LAN system. Therefore, the importance of each logical path is determined by judging the importance of each logical path from such a viewpoint, holding an appropriate weight in the weight holding means, and subjecting it to correction processing of the state determination value by the correcting means. This is reflected in the corrected state judgment value .

According to the duplex LAN system of the present invention, utilizing the system characteristic that each device is connected to both of two LANs, and two logical transmission paths are configured by connecting logical paths. Collecting communication state information consisting of information elements indicating communication states in all logical paths, and operating in a redundant LAN system based on the number of devices involved in each of the two logical transmission paths based on this information A transmission path used for data transmission can be determined . Therefore, in the case where the both the logical system utilizing transmission path and the other non-active lines to be currently active system more anomalies occur even both lineage transmission path respectively The system operation can be reliably maintained by rationally determining the logical transmission path to be the active system based on the number of devices involved in the abnormality and executing the switching.

In particular, according to the fourth duplicated LAN system, even if the abnormality in the logical path connecting to one of the logical transmission path occurs, the communication state information over the logical paths connected to the other of the logical transmission paths And the collected communication status information can be returned in accordance with a diagnostic message from another device, so that it is possible to collect communication status information related to all devices without omission. Thereby, the legitimacy of the operation risk calculated | required based on communication status information can be guaranteed.

Further, according to the third redundant LAN system, the operation risk can be calculated by an extremely simple calculation, so that the cost required for constructing the redundant LAN system can be reduced.
Furthermore, according to the fifth redundant LAN system , an operational risk can be obtained in consideration of the importance of each logical path, so that an abnormality relating to at least one device occurs in the system corresponding to the transmission path of each system. Even in complicated cases like this, it is possible to obtain a reasonable operation risk in each system and to switch to a logical transmission path that can maintain an advantageous operation state based on this. .

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 shows a first embodiment of a redundant LAN system according to the present invention.
The duplex LAN system shown in FIG. 1 is a monitoring control system for the purpose of remote monitoring of, for example, a dam. In this supervisory control system, the duplicated data collection devices 201 ₀ , 201 ₁ , the measuring devices 202, 203, 204 installed independently, and the duplicated switching determination devices 210 ₀ , 210 ₁ each have two ports P. _1, are physically connected via the _{P 2} two cables connected to the physical LAN 205 ₀ and the physical LAN 205 _1.

Also, the data collection device 201 ₀ shown in FIG. 1, a logical path is set to each measurement device 202, 203, 204 and the switch judgment unit 210 ₀ between ports _{P 1} mutually connected to physical LAN 205 _0, these logical transmission path by the logical path (hereinafter, referred to as 0-based virtual LAN) is formed. Similarly, logical paths are set between the ports P ₂ connecting the data collection device 201 ₁ , the measurement devices 202, 203, 204, and the switching determination device 210 ₁ shown in FIG. 1 to the physical LAN 205 _1. Another logical transmission path (hereinafter referred to as a 1-system virtual LAN) is formed by these logical paths.

In the data collection devices 201 ₀ , 201 ₁ , the measurement devices 202, 203, 204 and the switching determination devices 210 ₀ , 210 ₁ shown in FIG. 1, the communication status collection unit 211 performs logical operations via the two virtual LANs described above. By exchanging a diagnostic message and a response message, which will be described later, with other devices connected to each other, communication state information relating to the communication state in each logical path constituting the above-described two systems of virtual LANs is collected.

Further, in the switching determination devices 210 ₀ and 210 ₁ shown in FIG. 1, the operation risk evaluation unit 212 determines each of the two systems of virtual LANs based on the communication state information collected by the communication state collection unit 211 described above. The operational risk is evaluated, and the evaluation result is provided to the processing of the switching control unit 213. The switching control unit 213 determines a virtual LAN to be an active system based on the operational risk obtained for each of the two virtual LANs. As a result, when switching of the active LAN is necessary The virtual LAN that becomes the active system is newly broadcasted to all the devices constituting the two-system virtual LAN.

Further, in the data collection devices 201 ₀ , 201 ₁ and the measurement devices 202, 203, 204 shown in FIG. 1, the monitoring data transmission unit 214 uses a port corresponding to the virtual LAN that is notified of the active system. The monitoring data, which is operation data in the monitoring control system, is sent out through the logical path set in this way, and used for data management processing by a monitoring data management device (not shown).

In FIG. 1, data collection device 201 _0, shows the detailed configuration measurement device 202 and the switch determining unit 210 _0, the data collection device 201 ₁ having these equivalent configurations, the measuring device 203, 204 and the switch judgment unit It is omitted the detailed structure for 210 _1.
In addition, the monitoring data management device described above operates the data collection devices 201 ₀ , 201 ₁ and the switching determination devices 210 ₀ , 210 _{1 that} are duplicated and the measurement devices 202, 203, and 204 that are not duplicated. The mode is set, and the non-operation mode is set for the other devices.

Next, a detailed configuration of the communication status collection unit provided in each of the above-described apparatuses will be described.
FIG. 2 shows a detailed configuration of the communication state collection unit. FIG. 3 is an explanatory diagram related to a process for collecting communication state information.
In the communication state collecting unit 211 shown in FIG. 2, the diagnostic message transmitting unit 222 via the LAN interface unit 221, via the physical LAN 205 ₀ and the physical LAN 205 ₁ shown in FIG. 1 physically connected to all of the A diagnostic message requesting the return of the diagnostic result stored in the destination device is sent to the device as the destination. Further, the communication state determination unit 223 shown in FIG. 2 automatically determines whether or not there is a response from the destination device until a predetermined time has elapsed after the diagnosis message is transmitted by the diagnosis message transmission unit 222 described above. The communication state in the logical path set between the device and the destination device is determined, and as shown in FIG. 3, the determination result is stored in the information storage unit 224 as a state determination value corresponding to the determination target logical path.

In FIG. 3, the diagnostic message sent from the device shown in each row is divided into a communication status table corresponding to the 0-system virtual LAN and a communication status table corresponding to the 1-system virtual LAN. Whether or not there is a response from the device (shown in each column of the table in FIG. 3) that is the destination of this diagnostic message, that is, whether or not the communication state in the logical path is normal is a logical “0” or An example of storing a state determination value indicated by logic “1” is shown. In FIG. 3, the data collection devices 201 ₀ and 201 ₁ shown in FIG. 1 are shown as “collection 0” and “collection 1”, respectively, and the measurement devices 202, 203, and 204 are shown as “measurement device a” and “collection device”, respectively. The measurement devices b ”and“ measurement device c ”are shown, and the switching determination devices 210 ₀ and 210 ₁ are shown as“ switch 0 ”and“ switch 1 ”, respectively. In FIG. 3, a column with a symbol “−” indicates that there is no state determination value because it corresponds to a combination of identical devices to which no logical path is set.

On the other hand, when a response message from another device arrives at the LAN interface unit 221, the information extraction unit 225 illustrated in FIG. 2 extracts communication state information included in the response message, and extracts the extracted communication state. The state determination value included in the information is stored in the information storage unit 224 corresponding to each logical path.
Also, the response message creation unit 226 shown in FIG. 2 automatically communicates with the communication status information accumulated in the information storage unit 224 as described above when a diagnostic message from another device arrives at the LAN interface unit 221. A response message including mode information indicating the operation mode set in the apparatus is created, and this response message is returned to the above-described diagnosis message transmission apparatus via the LAN interface unit 221. For example, as shown in FIG. 4, the response message creation unit 226 combines a header unit including mode information and identification information corresponding to the own device and an information unit including communication state information read from the information storage unit 224. Create a response message.

Next, an operation for collecting communication state information will be described.
FIG. 5 is a flowchart showing an operation for collecting communication state information.
For example, the diagnostic message sending unit 222 of the communication state collecting unit 211 provided in the switch determining unit 210 ₀ shown in FIG. 1, the 0-system switching determination unit 210 ₁ in the virtual LAN, data collection device ₂₀₁ 0, 201 ₁ and measurement In the logical path and the 1-system virtual LAN respectively set between the devices 202, 203, and 204, set in the switching determination device 210 ₁ , the data collection devices 201 ₀ and 201 _1, and the measurement devices 202, 203, and 204, respectively. Through the logical paths thus formed, diagnostic messages destined for the devices facing each other are sequentially sent (step 301 shown in FIG. 5).

When the response to the diagnostic message reaches the LAN interface unit 221 shown in FIG. 2 (affirmative determination in step 302 shown in FIG. 5), the communication status determination unit 223 determines the communication status related to the logical path to which the diagnostic message is sent. Is determined to be normal, and a state determination value indicating that is stored in the information storage unit 224 (step 303).
At this time, the information extraction unit 225 extracts the communication state information included in the information part of the response message, and stores the state determination value regarding each logical path included in the communication state information in the information storage unit 224. By storing, the contents of the information storage unit 224 are updated (step 304).

  On the other hand, when a response message to the above-described diagnostic message is not detected, steps 302 and 305 shown in FIG. 5 are repeated until a predetermined time T elapses, and when the time T has elapsed since the diagnosis message is transmitted. (Affirmative determination in step 305), the communication state determination unit 223 determines that the communication state related to the logical path to which the diagnostic message is transmitted is abnormal, and stores a state determination value indicating that in the information storage unit 224. (Step 306).

In this way, communication state information consisting of state determination values is collected in the process of exchanging diagnostic messages and response messages regarding each logical path, and when processing for all logical paths is completed, the determination of step 307 is affirmed. As a determination, the communication state information collection process is terminated.
All devices constituting the redundant LAN system shown in FIG. 1, by performing the acquisition process of the communication state information described above, respectively, represented by the cutting of the cable connecting the the part of the apparatus physical LAN 205 ₀ or physical LAN 205 ₁ As shown in FIG. 3, the information storage unit 224 of the communication status collection unit 211 provided in all the devices constituting the redundant LAN system is connected to all logical paths regardless of whether there is a failure related to the LAN. Communication state information including a state determination value is accumulated.

  This is because, as described above, in response to the reception of the diagnostic message, the response message creation unit 226 shown in FIG. 2 sets the communication status information regarding both virtual LANs stored in the information storage unit 224 at that time. This is because a response message including the response message is created and returned to the transmission source of the diagnostic message, so that information that cannot be directly collected in the transmission source device can be supplemented.

For example, the diagnostic message if you've missing cable connecting the measuring device 204 and the physical LAN 205 ₀ shown in FIG. 1, which transmits the measurement device 204 each of the other devices via the 0-system virtual LAN as the destination As shown in FIG. 3, the state determination value “1” indicating that the communication state is abnormal in the column corresponding to the measuring device 204 (the measuring device c in FIG. 3). Is stored in the communication state table corresponding to the 0-system virtual LAN. On the other hand, no response is returned to the information storage unit 224 of the communication status collection unit 211 provided in the measurement device 204 even for a diagnostic message transmitted to other devices via the 0-system virtual LAN. Since the communication status information including the status determination value indicating that is collected, when the diagnostic message arrives at this measuring device 204 via the logical path constituting the 1-system virtual LAN, the diagnostic message is displayed. On the other hand, a response message including the above-described communication state information is returned, and finally communication state information including state determination values for all logical paths is completed.

  The timing at which each device constituting the duplex LAN system collects the communication status information described above is specified by specifying an appropriate timing to the diagnostic message sending unit 222 of the communication status collection unit 211 provided in each device. It can be set arbitrarily. For example, if it is set that a diagnostic telegram is sent every certain period, information indicating the communication state in each virtual LAN can be collected for each period, and each state can be determined.

In addition, as a method for collecting state determination values related to each logical path, a method for determining a communication state related to a logical path with the diagnosis information transmission source using diagnostic information sent at regular intervals is adopted. It is also possible.
Next, a method for obtaining operational risk will be described.
FIG. 6 shows a detailed configuration of the operation risk evaluation unit. FIG. 7 shows an explanatory diagram related to the operation risk evaluation process.

In the operation risk evaluation unit 212 illustrated in FIG. 6, the logical sum calculation unit 227 includes each of the communication status tables stored in the information storage unit 224 corresponding to the two systems of virtual LANs and corresponding to the destination device of the diagnostic message. An OR operation is performed on the column state determination values, and an abnormal addition value indicating whether each device is abnormally related to each of the two systems of virtual LANs is obtained.
For example, the communication state table corresponding to the virtual LAN of each system shown in FIG. 3 is processed by the above-described OR operation unit 227, so that an abnormality corresponding to the 0-system virtual LAN is obtained as shown in FIG. As an added value, logic “1” is obtained for each device. On the other hand, as the abnormal addition value corresponding to the 1-system virtual LAN, the data collection device 201 ₀ (shown as “collection 0” in FIG. 7) and the measurement device 202 (shown as “measurement device a” in FIG. 7). A logic “1” is obtained as the abnormal addition value corresponding to the other, and a logic “0” is obtained as the abnormal addition value corresponding to the other devices.

Based on the abnormality addition value obtained in this way, the evaluation value calculation unit 228 illustrated in FIG. 6, for example, sums the above-described abnormality addition value for each corresponding virtual LAN, and the total value is associated with the corresponding virtual value. This is output as an operation risk related to the LAN, and used for processing of the switching control unit 213.
In the example shown in FIG. 7, the evaluation value calculation unit 228 obtains the operation risk “7” as the sum of the abnormal addition values obtained corresponding to the 0-system virtual LAN, while corresponding to the 1-system virtual LAN. Operation risk “2” is obtained as the sum of the abnormal addition values obtained in the above.

The operation risk value obtained in this way indicates the number of devices involved in the failure in each system virtual LAN. Therefore, the operation risk for each of the two system virtual LANs is extremely reasonably evaluated. It can be said that.
Therefore, based on the operational risk obtained in this way, the switching control unit 213 determines the lower operational risk (in the example of FIG. 7, the 1-system virtual LAN) as a new operational virtual LAN. By notifying each device of the switching destination virtual LAN via all logical paths, it is possible to reliably maintain the operation of the monitoring control system configured by the redundant LAN system.

In addition, taking into account the importance of each logical path, an operation that reflects the importance of each logical path by giving a value according to the importance for the status judgment value that indicates that an abnormality related to each logical path has been detected. You can also ask for risk.
The supervisory control system, the data collection device ₂₀₁ 0, 201 ₁ that it is necessary to exchange data with the three measuring devices 202, 203 and 204, the data collection device 201 ₀ and the measuring device 202, 203, 204 logical path set between the logical path and the data acquisition device 201 ₁ and the measuring device 202, 203, 204 are set between the Ya logical path connecting the data collection device 201 ₀ and data acquisition device 201 ₁ The importance is clearly higher than the logical path connecting the measuring devices 202, 203, and 204. The importance of the logical path connecting the data collection devices 201 ₀ , 201 ₁ and the three measuring devices 202, 203, 204 and the switching determination devices 210 ₀ , 210 ₁ is also the logical path connecting the same type of devices together. This is considered to be higher than the importance of.

FIG. 8 shows another configuration example of the communication state collection unit. FIG. 9 is a flowchart showing an operation for collecting communication state information.
In the communication status collection unit 211 shown in FIG. 8 shown in FIG. 8, the importance level information holding unit 231 indicates importance level information indicating the importance level of each logical path by a 3-bit value corresponding to each logical path. Hold. This importance level information holding unit 231 holds, for example, importance level information “100” represented by a binary number of 3 bits corresponding to a logical path through which data is exchanged in the operating state of the system. The importance level information “010” and the importance level information “001” are held in correspondence with the logical path relating to 210 ₀ and 210 ₁ and the logical path connecting the same type of devices, respectively.

  Further, the state determination value adjustment unit 232 illustrated in FIG. 8 has received information for specifying the diagnosis target logical path from the diagnosis message transmission unit 222, and the communication state determination unit 223 sets the communication state to the diagnosis target logical path. When it is determined that there is an abnormality, the importance information corresponding to the corresponding logical path is read with reference to the importance information holding unit 231 described above, and this importance information is sent to the information storage unit 224. Adjust the state judgment value.

  That is, in the communication state collection unit 211 shown in FIG. 8, when an abnormality in the communication state is detected by the communication state determination unit 223 (affirmative determination in step 305 shown in FIG. 9), the determination result is step 311. Instead of storing the obtained state determination value as it is in the information storage unit 224, the state determination value is adjusted by the state determination value adjustment unit 232 described above, and the state determination in which the importance related to the logical path in which the abnormality is detected is reflected. The value is stored in the information storage unit 224 (step 312).

FIG. 10 shows an example in which the state determination value reflecting the importance of the logical path is obtained in this way.
Note that the communication state table corresponding to the 0-system virtual LAN shown in FIG. 10 includes the data collection device 201 ₀ (shown as “collection 0” in FIG. 10) and the measurement device 203 (“measurement device b” in FIG. 10). This indicates that an abnormal communication state has been detected in the logical path between On the other hand, the communication state table corresponding to the 1-system virtual LAN includes the logical paths between the data collection devices 201 ₀ and 201 ₁ (shown as “collection 0” and “collection 1” in FIG. 10), the measurement devices 202 and 204. Logical paths between the logical paths between each other (shown as “measuring device a” and “measuring device c” in FIG. 10) and measuring devices 203 and 204 (“measuring device b” and “measuring device c” in FIG. 10). This indicates that a communication state abnormality has been detected in the logical path between the logical paths between each other.

  Based on each communication state table obtained in this way, the state determination value stored in each column corresponding to the destination device of the diagnostic message by the OR operation unit 227 of the operation risk evaluation unit 212 shown in FIG. As shown in FIG. 10, by performing a logical OR operation for each bit, an abnormal addition value in which importance is reflected in a logical path in which an abnormality is detected is obtained for each device, and an evaluation value calculation is performed. Part 228 is used for processing.

Therefore, by adding up the abnormal addition values in the evaluation value calculation unit 228, the operational risk value can reflect the importance of the logical path in which the communication abnormality is detected, as well as the number of devices involved in the communication abnormality. it can.
For example, when the operation risk evaluation unit 212 performs the above-described processing based on the communication state table shown in FIG. 10, the operation risk value “8” and the operation risk corresponding to the 0-system virtual LAN and the 1-system virtual LAN, respectively. The value “5” is obtained. The result is an evaluation result indicating that towards the 1-system virtual LAN is a data collection possible to the data collection device 201 ₀ from the measuring apparatus 203 is advantageous transmission path, the operation and maintenance of the monitoring and control system This is a desirable result.

  In this way, regardless of the number of devices involved in the abnormal communication state, the operational risk is evaluated in consideration of the effect on the data exchange in the operational state. Even in a complicated case where communication status abnormalities occur in a plurality of logical paths, the operational risk in each virtual LAN can be legitimately evaluated, and a virtual LAN advantageous for maintaining the operation of the system can be reliably selected.

For example, in the state represented by the communication state table as shown in FIG. 10, the switching determination unit 210 _0, for all devices constituting the redundant LAN system, the fact that the operating LAN 1 system virtual LAN same and multicast notification, by executing the switching operation LAN to one system virtual LAN, data collection device 201 ₀ via the 1-system virtual LAN, continue to collect data from all of the measuring device 202, 203, 204 Therefore, the function as the monitoring control system can be reliably maintained.

Further, it is possible to set a weight to the state determination value based on whether or not the source device and the destination device of the diagnostic message are in operation.
FIG. 11 shows another configuration example of the communication state collection unit.
In the communication status collection unit 211 shown in FIG. 11 shown in FIG. 11, the operation information holding unit 233 corresponds to each device constituting the redundant LAN system and whether each is in an operation state or a non-operational state. Operation information indicating is stored. As described above, when the data collection device 201 ₁ and the switching determination device 210 ₁ are set to the non-operation mode and the operation mode is set to another device, the data collection is performed as illustrated in FIG. logic "0" is held in the operation information holding section 233 as the operation information corresponding to the apparatus 201 ₁ and the switch determining unit 210 _1, corresponding to the data collection device 201 _0, measuring device 202, 203, 204 and the switch judgment unit 210 ₀ The operation information holding unit 233 holds logic “1” as the operation information to be performed.

  Further, the state determination value adjustment unit 234 shown in FIG. 11 receives information related to the destination device of the diagnostic message from the diagnostic message transmission unit 222, and the communication state determination unit 223 indicates that the communication state abnormality is present in the diagnosis target logical path. When it is determined that there is, the operation information held in the operation information holding unit 233 corresponding to the destination device described above is read, and the communication state is determined according to the combination of the operation information of the own device and the operation information of the destination device. The state determination value obtained by the determination unit 223 is adjusted, and the adjusted result is stored in the information storage unit 224 as a final state determination value.

  The state determination value adjustment unit 234, for example, when it is found by referring to the operation information holding unit 233 that the operation mode is set in both the diagnosis message transmission source device and the diagnosis message destination device. Then, the state determination value “1” indicating that the communication state obtained by the communication state determination unit 223 is abnormal is adjusted according to the adjustment value shown in the table shown in FIG. A new state determination value “10” represented by a decimal number is stored in the information storage unit 224. On the other hand, when the operation information is another combination, the adjustment value shown in FIG. 12B is a numerical value “01” represented by a 2-bit binary number, and thus the state obtained by the communication state determination unit 223 The determination value is stored in the information storage unit 224 as it is.

  That is, in the communication state collection unit 211 shown in FIG. 11, as shown in FIG. 9, when an abnormality in the communication state is detected by the communication state determination unit 223 (affirmative determination in step 305 shown in FIG. 9). The state determination value adjustment unit 234 described above adjusts the state determination value obtained by the communication state determination unit 223 based on the weight determined according to the operation state of the transmission source and destination of the diagnostic message (step 312). ).

In this way, the state reflecting the importance of each logical path related to the operation of the entire redundant LAN system by obtaining the state determination value reflecting the weight determined according to the operation state of the transmission source and destination of the diagnostic message A judgment value can be obtained.
FIG. 13 shows an example of collected communication state information.
In 0-system virtual LAN, the data collection device 201 ₀ where the operation mode is set measuring device 203 (shown as a "collection 0" and "measuring device b" in FIG. 13) and also the switching operational mode is set determination 210 ₀ and the measuring apparatus 204 when ( "switch 0" and "measuring device c" shown as in FIG. 13) of the communication state in the logical path between the abnormality occurs, the communication state table corresponding to the 0-system virtual LAN A state determination value “10” is set in each corresponding column.

The communication state table corresponding to the 0-system virtual LAN, by subjecting the arithmetic processing by the logical sum computation section 227 shown in FIG. 6, the data collection device 201 _0, the measuring device 203, 204 and the switch judgment unit 210 _0, Since the 2-bit abnormal addition value “10” is obtained for each, the evaluation value calculation unit 228 tabulates these values, so that the number of devices involved in the failure is “4”. An evaluation result indicating a high operational risk of “8” is output.

On the other hand, if the abnormality occurring in the 1-system virtual LAN is, for example, if the LAN cable connected to the port P ₁ of the data collection device 201 ₁ is disconnected, as shown in FIG. 13, it corresponds to the 1-system virtual LAN. state determination value "01" is set in each column corresponding to the data acquisition device 201 ₁ of the communication state table.
By using the communication state table corresponding to this 1-system virtual LAN for the arithmetic processing by the logical sum operation unit 227 shown in FIG. 6, a 2-bit abnormal addition value “ 01 ”is obtained, and the evaluation value calculation unit 228 counts these, so that the number of devices involved in the failure is“ 7 ”, which is greater than the number of devices involved in the failure in the 0-system virtual LAN. In spite of the large number, an evaluation result indicating a value “7” smaller than the operation risk in the 0-system virtual LAN is output.

This result is an advantageous one system virtual LAN data transfer is possible between the operational data collection and the switch judgment unit 210 ₀ and the data collection device 201 ₀ to the data collection device 201 ₀ from the measurement device 203 This is an evaluation result indicating that it is a transmission path, and is a desirable result for maintaining the operation of the supervisory control system.
In this way, by simply evaluating the operational risk in consideration of the number of devices involved in the abnormal communication state and the impact on data exchange in the operational state, a plurality of logical LANs are respectively used in the two virtual LANs. Even in a complicated case where an abnormal communication state occurs in the path, it is possible to legitimately evaluate the operation risk in each virtual LAN and reliably select a virtual LAN advantageous for maintaining the operation of the system.

For example, in the state represented by the communication state table as shown in FIG. 13, the switching determination unit 210 _0, for all devices constituting the redundant LAN system, the fact that the operating LAN 1 system virtual LAN same and multicast notification, by executing the switching operation LAN to one system virtual LAN, data collection device 201 ₀ via the 1-system virtual LAN, continue to collect data from all of the measuring device 202, 203, 204 Therefore, the function as the monitoring control system can be reliably maintained.

  Of course, it is also possible to adjust the state determination value using a larger weight than the above-described example according to the operating state of the transmission source and destination of the diagnostic message.

According to the present invention, a virtual LAN, which is a virtual transmission path used for transfer of operation data related to system operation, is evaluated according to the result of evaluating operation risk based on communication state information collected for each of these virtual LANs. In addition, it is possible to perform switching independently of the operation system switching in each duplexed device.
As a result, for example, when a failure occurs in a logical path included in the active virtual LAN that is the transmission path of the active data, the active system is maintained while maintaining the operation state of each device constituting the redundant LAN system. By switching only the virtual LAN, the operation of the entire system can be maintained. In other words, it is possible to maintain the operation state of the entire system by utilizing a configuration in which the LAN for data transfer is duplicated, so it is necessary to maintain the system operation as in the case of a supervisory control system. It is extremely useful in the system.

1 is a diagram showing a first embodiment of a duplex LAN system according to the present invention. It is a figure which shows the detailed structure of a communication status collection part. It is a figure explaining communication status information. It is a figure which shows the structural example of a response message. It is a flowchart showing the operation | movement which collects communication status information. It is a figure which shows the detailed structure of an operation risk evaluation part. It is explanatory drawing regarding an operational risk evaluation process. It is a figure which shows another structural example of a communication status collection part. It is a flowchart showing the operation | movement which collects communication status information. It is explanatory drawing regarding an operational risk evaluation process. It is a figure which shows another structural example of an operation state collection part. It is a figure explaining adjustment of a state judgment value. It is a figure which shows the example of the collected communication status information. It is a figure which shows the structural example of a general monitoring control system. It is a figure which shows the structural example of the system using two LAN. It is a figure which shows the structural example of the monitoring control system with which LAN was duplicated.

Explanation of symbols

201 Data collection device 202, 203, 204 Measuring device 205 Physical LAN
210 switching determination device 211 communication state collection unit 212 operation risk evaluation unit 213 switching control unit 221 LAN interface unit 222 diagnostic message transmission unit 223 communication state determination unit 224 information storage unit 225 information extraction unit 226 response message generation unit 227 OR operation unit 228 Evaluation value calculation unit 231 Importance information holding unit 232 State determination value adjustment unit 233 Operation information holding unit 234 State determination value adjustment unit 401 Monitoring devices 402, 403, 404 LAN

Claims (5)

In a duplexed LAN system configured by physically connecting a plurality of devices including at least one pair of duplexed devices to each of two LANs,
Using a physical connection between each of the plurality of devices and the two LANs, two systems of logic from logical paths that are logically set via the two LANs between the plurality of devices. Transmission path forming means for forming a typical transmission path;
State information collection means for collecting communication state information indicating a communication state for all logical paths set in the two LANs;
Based on the communication status information collected by the status information collecting means, based on the number of devices involved in each of the two logical transmission paths, one of the two logical transmission paths is Route switching means for switching the transmission route by notifying the plurality of devices that the transmission route is used for transmission of operational data in the duplex LAN system ;
A redundant LAN system comprising: In a duplexed LAN system configured by physically connecting a plurality of devices including at least one pair of duplexed devices to each of two LANs,
Using a physical connection between each of the plurality of devices and the two LANs, two systems of logic from logical paths that are logically set via the two LANs between the plurality of devices. Transmission path forming means for forming a typical transmission path;
State information collection means for collecting communication state information indicating a communication state for all logical paths set in the two LANs;
Based on the communication status information, for each of the two logical transmission paths, a risk evaluation means for evaluating operational risk,
Based on the evaluation result of the risk evaluation means, broadcast notification to the plurality of devices that one of the two logical transmission paths is a transmission path used for transmission of operational data in the dual LAN system. A path switching means for switching the transmission path at
With
The risk assessment means includes
An arithmetic operation that performs a logical sum operation on the state determination values related to each device included in the communication status information and outputs the logical sum operation result as an abnormal addition value indicating whether or not each device is involved in a communication state abnormality A duplex LAN system comprising: means . The duplex LAN system according to claim 2 ,
The risk assessment means includes
The abnormal addition values obtained for the respective devices by the arithmetic means are totaled for each of the two logical transmission paths, and the sum of the abnormal addition values is calculated for each of the two logical transmission paths. A redundant LAN system characterized by further comprising an aggregation means for outputting as an operation risk. The duplex LAN system according to any one of claims 1 to 3,
The state information collecting means includes
A diagnostic message sending means for sending a diagnostic message to all the devices that are provided in the plurality of devices and are physically connected via at least one LAN;
A determination unit that is provided in the plurality of devices and determines whether normal data transmission is possible via a logical path to a destination device based on the presence or absence of a response message to the diagnostic message;
An information accumulating unit that is provided in the plurality of devices and accumulates a state determination value indicating a determination result obtained by the determination unit corresponding to each logical path;
The information on the logical paths belonging to the two logical transmission paths in response to the reception of a diagnostic message from the apparatuses that are provided in the plurality of apparatuses and are physically connected via the both LANs. Response means for returning a response message including communication state information consisting of collected state determination values in the accumulation means;
A duplex LAN system , comprising: an extraction unit provided in the plurality of devices, which extracts communication state information included in the received response message, and uses the extraction unit for integration processing by the information integration unit .   The duplex LAN system according to claim 4, wherein
  The information accumulation means includes
  Weight holding means for holding weights indicating the importance of the role of the logical path in the redundant LAN system for all logical paths set in the redundant LAN system;
  Correction means for correcting a state determination value indicating a determination result corresponding to each logical path obtained by the determination means based on the corresponding weight held in the weight holding means;
A state determination value storage means for holding the corrected state determination value corresponding to each logical path.
  A redundant LAN system characterized by that.

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