JPH08149145A - Lan system - Google Patents

Abstract

PURPOSE: To keep an inter-node communication function without stopping the system even in the case of fault occurrence state of a bus or a node equipment or of maintenance with respect to the LAN system of bus configuration. CONSTITUTION: This system has 1st and 2nd buses A, B, one of which is used for an active system and the other of which is used for a standby system, and 1st and 2nd node equipments of each of plural nodes one of which is used for an active system and the other of which is used for a standby system, and each node equipment has a selection connection means to be connected selectively to either of the 1st and 2nd buses A, B and the selection connection means connects the node equipment used for the active system to the bus to be used for the active system and connects the node equipment used for the standby system to the bus to be used for the standby system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a LAN system having a bus structure. In LAN communication with a bus configuration, there is a demand for improved reliability so that the communication function can be maintained in any case.

[0002]

2. Description of the Related Art At present, LANs have become widespread and are becoming indispensable for building LANs using personal computers in offices and managing facilities using LANs in buildings. However, the LA currently in use
The N system has one for each of a plurality of nodes on one bus.
A configuration in which two node devices are connected is common.

[0003]

In a conventional LAN system having a bus structure, communication between nodes becomes impossible even if there is an abnormality in either the bus or a node device connected to the bus. In addition, it is necessary to suspend the system for maintenance. An object of the present invention is to provide a LAN system capable of maintaining an internode communication function without stopping the system even when an abnormality occurs in a bus or a node device and at the time of maintenance.

[0004]

FIG. 1 shows the basic configuration of a LAN system in which a plurality of nodes are connected by a bus according to the present invention. In FIG. 1, A is a first bus, B is a second bus, 1 is a first node device at a first node, 2 is a second node device at the first node, and 3 is a second node device. The first node device 4 in the node is a second node device in the second node. The SEL in each node device is a selective connection means.

The above-mentioned first and second buses A and B
Is for using one as an active system and the other as a standby system. The first and second node devices in each of the above-mentioned plurality of nodes are for using one as an active system and the other as a standby system. The first of the above
Each of the second node device and the second node device has a selective connecting means SEL for selectively connecting to either one of the first and second buses A and B, and the selective connecting means SEL.
For using the node device used as the above-mentioned active system among the above-mentioned first and second node devices among the above-mentioned first and second buses A and B as the above-mentioned active system. The node device connected to the bus and used as the above-mentioned backup system is used as the above-mentioned backup system.

(1) In the above basic configuration of the present invention, each of the first and second node devices in each of the plurality of nodes includes the first and second nodes in the plurality of nodes. It is possible to have a working / standby system node information holding unit that holds working / standby system node information indicating whether the device is used as a working system or as a standby system.

(2) In the configuration of the above (1), in each of the plurality of nodes, each of the first and second node devices has the active system / node in its own node device.
When the working system / spare system node information held by the spare system node information holding unit is updated, the working system / spare system node information holding unit in the other node device of the first and second node devices is updated. Working / spare node information transfer means for transferring the updated working / spare node information, and the working / spare node information transfer in the other node device of the first and second node devices Means for updating the active / spare node information held by the active / spare node information holding means in its own node device by the updated active / spare node information transferred by the means. It is possible to have a system / spare system node information updating means.

(3) In the above configuration (1), each of the first and second node devices in each of the plurality of nodes has its own node device when the respective nodes are started up. Is the active node device,
Startup node information indicating that the own node device is the active node device and the other node device of the node is the standby node device on at least one of the first and second buses. The startup node information sending means for sending to the node and the startup node information sent from another node are sent to the bus of the first and second buses to which the own node device is connected. Means for detecting that the active node has been detected, and means for inputting the startup node information when the startup node information is detected, and the active system in its own node device using the input startup node information. And / and means for updating the active / spare node information held by the spare node information holding means.

(4) In the above configuration (3), instead of each of the first and second node devices having means for detecting that the start-up node information is transmitted, The bus has a master node in addition to the plurality of nodes, and the master node receives the start-up node information transmitted to at least one of the first and second buses. And means for transmitting the received startup node information to each of the first and second node devices of the plurality of nodes via the first and second buses.

(5) In the above configuration (1), each of the first and second node devices in each of the plurality of nodes has a failure in its own node device, and Means for detecting at least one of disconnection of its own node device from the bus; failure of its own node device when the own node device is the active node device; and When at least one of the disconnection of its own node device from the bus is detected, at least one of the occurrence of the fault and the disconnection from the bus is detected as the first and the first. Means for notifying the other node device of the second node device and the other node device of the first and second node devices when the other node device is the active node device When receiving the notification of at least one of the occurrence of a failure in the other node device and the disconnection from the bus, the active / spare node information holding means in its own node device is A means for updating the retained active / standby node information so that the own node device is the active node device; and, when receiving the notification, the own node device is the active node device. Means for sending information indicating that there is at least one of said first and second buses;
Among the first and second buses, the information indicating that the own node device is the active node device is transmitted, and the selective connection means (SEL) in the own node device is switched, And a means for controlling to connect to the bus of the active system.

(6) In the above configuration (5), the bus has a master node in addition to the plurality of nodes, and the master node is at least one of the first and second buses. Means for receiving information indicating that the node device of its own is an active node device, and information indicating that the received node device of the own node device is an active node device. Means for transmitting to each of the first and second node devices of the plurality of nodes via the first and second buses.

(7) In the above configuration (1), each of the first and second node devices in each of the plurality of nodes uses the first and second buses as an active system. 3. The LAN according to claim 2, further comprising an active system / spare system bus information holding unit that holds active system / spare system bus information indicating whether it is used or used as a standby system.
system.

(8) In the configuration of the above (7), in each of the plurality of nodes, each of the first and second node devices has the active system / node in its own node device.
When the working / spare bus information held by the spare bus information holding means is updated, the working / spare bus information holding means in the other node device of the first and second node devices is updated. Active / spare bus information transfer means for transferring the updated active / spare bus information, and the active / spare bus information transfer in the other node device of the first and second node devices According to the updated working / standby bus information transferred by the means,
It may have an active / spare bus information update means for updating the active / spare bus information held by the active / spare bus information holding means in its own node device.

(9) In the above configuration (6), when the node device of each of the first and second node devices in each of the plurality of nodes is used as an active system. Of the first and second buses, means for detecting that communication via the working bus is disabled, and the means for detecting that communication is disabled. Means for transmitting an instruction to the other node device of the first and second node devices so that the other node device switches to the active system; and the other node device of the first and second node devices , A means for receiving the instruction, and the active / standby node information held by the active / standby node information holding means in the own node device when the instruction is received Is the active node device And a means for updating the working / standby system bus information held by the working / standby system bus information holding means in its own node device when the instruction is received. A means for updating so as to be exchanged with the system, information indicating that its own node device is a node device of the active system, and an active system / spare system bus exchanged between the active system and the standby system Means for sending information to at least one of the first and second buses, and the own node device sent to at least one of the first and second buses is a working node device Information indicating that the active system / standby system bus information has been exchanged between the active system and the standby system, and the active system / spare system node information holding means in its own node device. And the current system / pre And a means for updating the contents of the storage system bus information holding means.

(10) In the above configuration (9), the bus has a master node in addition to the plurality of nodes, and the master node is at least one of the first and second buses. Means for receiving the information indicating that the node device of its own is a node device of the active system, and the active system / spare system bus information exchanged between the active system and the standby system. , The received information indicating that the node device of its own is a node device of the active system, and the active system / the standby system exchanged between the active system and the standby system.
Means for transmitting the backup bus information to each of the first and second node devices of the plurality of nodes via the first and second buses.

(11) In the above basic configuration of the present invention, at least one of the plurality of nodes is a master node, and the first and second nodes of the plurality of nodes are the same.
When the respective node devices are standby node devices connected to the backup bus, the standby node device of the master node and the backup node of each node It is possible to have means for communicating with the device via the backup system bus for confirming the normality of the backup system bus and the standby system node device in each of the nodes.

[0017]

The LA according to the invention, as shown in FIG.
According to the N system, normally, in each node, by connecting the active node device to the active bus (by the connection control of the selection control means), the active bus is connected between the active node devices. Communication can be performed via.

If there is an abnormality in the node device of the active system at a certain node, another node device of that node is connected to the bus of the active system (by the connection control of the selection control means). In this case, the other node device serves as the active node device, and communication between the other node device and the other active node device can be taken over via the active bus.

If an abnormality is found in the bus of the current system, one method is to use the other (standby system).
Use the bus as the active bus, and connect the node device of all the nodes that have been used as the active node device until then to the other (standby) bus. (Selection control means connection) may be switched to, but the connection of the selection control means is not switched, and the spare bus is used as the active bus until that time. The connected standby node device may be used as the active node device.

In any case, according to the LAN system of the present invention, even if an abnormality occurs in the active node device, or an abnormality occurs in the active bus, or during maintenance. Also, the inter-node communication function can be maintained without stopping the system. (a) In the above basic configuration of the present invention, each of the first and second node devices in each of the plurality of nodes has a working system in which the first and second node devices in the plurality of nodes are in an active system. Each node device has an active node / standby node information holding unit that holds active node / spare node information indicating whether the node is used as a backup node or a standby node. It is possible to correctly identify the system node device and the standby node device for communication.

(B) In the configuration of (a) above, in each of the plurality of nodes, each of the first and second node devices has the working / spare node information in its own node device. When the active / spare node information held by the holding means is updated, the first and second nodes are updated.
The active / spare node information transfer means for transferring the updated active / spare node information to the active / spare node information holding means in the other node device of the node device, Based on the updated active / spare node information transferred by the active / spare node information transfer means in the other node device of the second node device, the active / spare node in its own node device / If the backup system node information holding means holds the working system / standby system node information updating means for updating the working system / standby system node information, only one of the first and second node devices in each node is provided. , When receiving the active / spare node information of the first and second node devices in the other node directly or indirectly from each node, Definitive first and second node devices each active / standby node information holding means can be kept always matching the active / standby node information retained.

(C) In the configuration of (a) above, each of the first and second node devices in each of the plurality of nodes has its own node device in operation when the node is started up. When the node device is a system node device, startup node information indicating that the node device of its own is the active node device and the other node device of the node is the standby node device is provided in the first and the first node information. The start-up node information transmitting means for transmitting onto at least one of the two buses, and the one of the first and second buses, which is transmitted from another node, on the bus to which its node device is connected. Using the means for detecting that the startup node information is transmitted, the means for inputting the startup node information when the startup node information is detected, and the input startup node information The current system in which the active / standby node information holding means in its own node device holding /
And a means for updating the spare node information, as soon as the new node becomes a source / recipient of the LAN system and can perform a predetermined function, the active node / standby node information at the node is changed to The node device of each node can be distributed to all other nodes of the LAN system, and the node device of each node inputs its active / spare node information and stores the active / spare node information holding means in its own node device. Update the content. This will cause the new node to
Immediately after the system becomes a source / recipient of the system and a predetermined function is possible, the contents of the active / spare node information holding means of the node devices of all other nodes of the LAN system are updated to the latest information. .

(D) In the configuration of (c) above, instead of each of the first and second node devices having means for detecting that the start-up node information is transmitted, The bus has a master node in addition to the plurality of nodes, and the master node receives the start-up node information transmitted on at least one of the first and second buses. And a means for transmitting the received startup node information to each of the first and second node devices of the plurality of nodes via the first and second buses, The active / spare node information in the above new node is once notified from the node device in this new node to the above master node, and then from this master node to all other nodes. It will be notified to the node device over de.

(E) In the above configuration (a), each of the first and second node devices in each of the plurality of nodes has a failure in its own node device, and Means for detecting at least one of the disconnection of the node device from the bus and the fact that the own node device has failed when its own node device is the active node device, and When at least one of the disconnection of the node device from the bus is detected, at least one of the fault occurrence and the disconnection from the bus is detected as the first and second Means for notifying the other node device of the other node device, and when the other node device of the first and second node devices is the active node device, the other node device When the at least one of the occurrence of a failure in the other node device and the disconnection from the bus is received, the active / spare node information holding means in its own node device holds Means for updating the active / spare node information so that its own node device is the active node device; and, when receiving the notification, the own node device is the active node device. Means for sending information indicating that to at least one of the first and second buses,
Among the first and second buses, the information indicating that the own node device is the active node device is transmitted, and the selective connection means (SEL) in the own node device is switched, When a failure occurs in one of the active node devices or when one of the active node devices is disconnected from the bus, a means for controlling to connect to the active bus is provided. , In that node, the connection with the bus of the active system was immediately switched so that the node of the standby system became the node device of the active system, and the node of the standby system newly became the node device of the active system. The active / spare node information indicating the is sent to the bus and notified to all other nodes.

(F) In the above configuration (e), the bus has a master node in addition to the plurality of nodes,
The master node receives the information indicating that the node device of its own, which is transmitted to at least one of the first and second buses, is a node device of an active system, and the master node which has received the information. And means for transmitting information indicating that the node device is a working node device to each of the first and second node devices of the plurality of nodes via the first and second buses. Then, the active / spare node information indicating that the standby node has newly become the active node device is notified to all other nodes via the master node.

In this way, when communication is disabled due to a single failure of a node device, the spare node device of the failed node device senses the failure, and further, another node is used by using the bus of the active or standby system. The above failure will be reported to. Then, each node receiving the failure message rewrites the active / spare node information held by the active / spare node information holding means in its own node device, and the spare node device of the failed node device By switching the bus that accesses the active bus from the standby bus, a communication system that does not use the faulty node device is configured.

Also, when a certain node device is disconnected from the bus of the active system, similarly, the node device of the standby system of the node senses the disconnection by the hard wire, and the node device separated by the same method is used. A communication system using a spare node device can be configured. (g) In the configuration of (a) above, whether each of the first and second node devices in each of the plurality of nodes uses the first and second buses as an active system, If each node device has a working / standby bus information holding unit that holds working / standby bus information indicating whether it is being used as a stand-by system, each node device correctly recognizes the working system and the stand-by bus and communicates. It can be performed.

(H) In the configuration of (g) above, each of the first and second node devices in each of the plurality of nodes holds the working / standby system bus information in its own node device. When the working / standby system bus information held by the means is updated, the updated working / standby system bus information holding means in the other node device of the first and second node devices is updated. Active / standby system bus information transfer means for transferring system / standby system bus information;
And the updated active / standby bus information transferred by the active / standby bus information transfer means in the other node device of the second node device, the active system in its own node device. / Only one of the first and second node devices in each node, if there is an active / standby bus information updating means for updating the active / standby bus information held by the standby bus information holding means. But,
Even when the active / standby bus information of the first and second node devices in the other node is directly or indirectly received from the other node, the first and second nodes in each node are received. The active / spare bus information held by the active / spare bus information holding means of each device can always be matched.

(I) In the above configuration (g), when each of the first and second node devices in each of the plurality of nodes uses its own node device as an active system, Of the first and second buses, means for detecting that communication via the working bus is disabled, and the first and second means when the communication is detected to be disabled. Means for transmitting an instruction to the other node device of the second node device to switch to the active system, and the other node device of the first and second node devices, A means for receiving an instruction and, when the instruction is received, the active / standby node information held by the active / standby node information holding means in its own node device is used by the own node device. System node device And a means for updating the active / standby system bus information held by the active / standby system bus information holding means in its own node device when the instruction is received. And information indicating that the node device of its own is an active node device, and active / spare bus information exchanged between the active and standby systems. Means for sending on at least one of the first and second buses, and the own node device sent on at least one of the first and second buses is a working node device. It receives information indicating that there is information, and active / spare system bus information exchanged between the active and standby systems, and stores the active / spare node information holding means in its own node device. The working / standby system By providing a means for updating the contents of the bus information holding means, even if it is difficult to identify a failure location such as a bus or a node apparatus when communication is disabled due to some failure, the failure detection node apparatus can Information indicating that the node device instructed to switch to the node device of the other system is the node device of the above-mentioned own node device and the node device receiving the instruction, and switching between the active system and the standby system The active / standby bus information can be notified to all other nodes. Therefore, the communication system can be constructed immediately by using the bus and the node device which have been the standby system until then as the active system without evaluating the failure at the time of switching.

(J) In the above configuration (i), the bus has a master node in addition to the plurality of nodes,
This master node sends information on at least one of the first and second buses, the information indicating that the own node device is the active node device, and
Means for receiving the active / standby bus information exchanged between the active system and the standby system, and the above-mentioned received information indicating that the own node device is the active node device,
And, the active / spare system bus information exchanged between the active system and the standby system is sent to each of the first and second node devices of the plurality of nodes via the first and second buses. When it has a means for transmitting, this information will be notified to all the other nodes via the master node.

(K) In the above basic configuration of the present invention,
At least one of the plurality of nodes is a master node, and each of the first and second node devices of the plurality of nodes is connected to the standby system bus. When the node device is a standby system, between the node device of the standby system of the master node and the node device of the standby system of each node, via the bus of the standby system, the bus of the standby system, and In the case of having a means for performing communication for confirming the normality of the node device of the standby system in each node, a standby bus is used between the master node and each node connected to the standby system in the steady state. For example, by exchanging data in a polling manner, even during normal communication between the active node devices via the active bus, the standby node device You can always monitor the health of the spare system with backup system bus.

(1) Even when the master node is duplicated, the active / spare node information holding means holds the active / spare node information about the duplicated master node in all nodes. Therefore, the node device of each node can identify which master node is the active node or the standby node.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described in detail below with reference to the accompanying drawings. First Embodiment FIG. 2 shows, as a first embodiment of the present invention, a configuration example of a LAN system in which both nodes and buses are duplicated.

In FIG. 2, reference numeral 100 is a master node device, 101 and 102 are two node devices belonging to the node block 1 for duplication, 103 and 104 are two node devices belonging to the node block 2 for duplication, and 105. And 106 are two node devices for duplication belonging to the node block 3, and A and B
Are two buses for duplication. In each node device, SEL is a selector that connects the node device to one of the buses A and B. In each node block, one of the two node devices is connected to the active bus and the other is connected to the standby bus. Figure 2
In, the active node device is indicated by a block with a thick frame. Further, the node device connected to the bus by the selection of the selector SEL is shown by connecting the bus with a solid line, and the node device not selected by the selector SEL and not connected to the bus is It is shown by connecting a line between and.

In the embodiment of FIG. 2, only the node device of the master node is not duplicated. In this embodiment, the bus to which the master node device 100 is connected becomes the active bus. Thus, by duplicating the buses, even if the bus A is disconnected, the bus B can be selected to continue operating the system.

In the LAN system of FIG. 2, each node device 100, ... 106 has an address management table 200 ,. As shown in Table 1, the address management table indicates which of the duplicated bus and the duplicated node device of each node block is used as the active system and which is the standby system ( 3 is a table showing the address of the node device). In Table 1, "001", "002",
... "006" indicates the node devices 101 and 1 respectively.
02, ... 106 addresses. In this embodiment, since the master node device is not duplicated, there is no master node column.

When wishing to communicate with a certain node, each node device can recognize the address of the active node device of that node by this address management table.

[0038]

[Table 1]

Start- up of Node Device FIG. 3 is a diagram for explaining the operation when starting a node device in the configuration of FIG. In the configuration of FIG. 2, a case where the two node devices 101 and 102 of the node block 1 are started up from the state where the node block 1 is stopped will be described. First, the started-up node device notifies the master node of its own start-up via the active bus (see FIG. 3). This notification includes information indicating the addresses of the node device used as the active system and the node device of the standby system in the newly started node block 1. Here, in FIG. 3, the two node devices 101 and 102 of the node block 1 are both shown to transmit the notification to the master node device 100, but the node device used as the active system in the node block 1 Only one may make the above notification.

The master node device 10 that received the above notification
0 updates the address management table 200 in the master node device 100 based on the above information included in this notification. Table 2 shows the address management table 20 before this update.
The contents of 0 and Table 3 show the contents of the updated address management table 200.

[0041]

[Table 2]

[0042]

[Table 3]

Next, the master node device 100, as shown in FIG. 4, includes the updated address management table 20 including the information on the start-up of the node block 1 described above.
The contents of 0 are broadcast to each node (including the node that has started up). Receiving this, each node device updates the address management table as shown in Table 3 according to this data. Here, instead of broadcasting the entire contents of the updated address management table 200, the notified information is
The node device of the newly started node block 1 is provided with the information on the node block other than this node block and the part related to the bus, and the node device of the node block other than this node block is newly started. You may transmit only the information of the part regarding block 1.

The notification of the above information from the master node device 100 to the spare node device is performed by the master node device 100 switching the selector of its own device to the spare bus, and transmitting this information through the spare bus. It may be transmitted to each spare node device connected to the spare bus. Alternatively, the active node device in each node block may notify the standby node device of the update information of the address management table.

In this way, the address management table of each node device is all updated, and each newly started node device can recognize which node device, the bus or another node block, is the active system. .

Hard Wire Connection In the configuration of FIG. 2, in each node block, each of the two node devices has a device fault occurrence signal EQP for notifying the other node device of the fault occurrence of its own device and its own device. Is configured to be capable of outputting a power-off signal PWD for notifying the other node device of the power-off of the other node device. Instead, it is also possible to output a switching instruction signal for outputting an instruction to switch so as to function as the active node device. The two node devices are connected by a plurality of hard wires so that the above signals output from both node devices are input to the other node device.

Occurrence of Fault in Node Device FIG. 5 shows that in the system operating state as shown in FIG. 2, a fault occurs in the node device used as the active node device in one node block, and communication is performed. FIG. 7 is an explanatory diagram of a failure relief method when a problem occurs in the user. As shown in FIG. 5, a case where a failure occurs in the node device 101 used as the active system in the node block 1 having the configuration of FIG. 2 will be described. Is shown below.

When the node device 101 fails in FIG. 5, the node device 102 detects the device failure occurrence signal EQP of the node device 101 (in FIG. 5) via the above hard wire, and the node device 102 in its own node device. The address management table is updated so that the local node device 102 is the active system and the other node device 101 that was the active system up to that time is the standby system (as shown in Table 4 to Table 5), and the bus A or The contents are broadcast to each of the other node blocks using the bus B (in FIG. 5). Each node device of the node block which received it updates the address management table (as in Table 4 to Table 5). Then, the node device 102
The bus to be accessed (selectively connected by the selector SEL) is switched from the standby bus B, which has been connected until then, to the active bus A, and the switching is completed. The node devices of the other node blocks can also recognize from the updated address management table that the active node of the node block 1 has switched from the node 101 to the node 102.

[0049]

[Table 4]

[0050]

[Table 5]

Disconnection of Node Device from Bus In FIG. 6, in the system operating state as shown in FIG. 2, the node device used as the active node device in one node block is connected until then. FIG. 7 is an explanatory diagram of a switching operation when the bus is disconnected from the existing bus.

As shown in FIG. 6, when the node device 101 used as the active system in the node block 1 having the configuration of FIG. 2 is disconnected from the bus of the active system which has been connected until then. Will be described. Similarly to the case where the active node device has failed, when the node device 101 is disconnected from the active bus A, the other node device 102 is connected to the other node device 101 via the hard wire. Sense this disconnection in.
Subsequent switching operations are exactly the same as when the above-mentioned active node device fails. For sensing via the hard wire, the device fault occurrence signal EQ
Although P may be used, a dedicated signal may be output in response to the detection of disconnection in the same manner as the device fault occurrence signal EQP and output to the other node device via the hard wire. The detection of the disconnection of the node device from the bus is well known in, for example, Ethernet, and the description thereof will be omitted.

Communication failure state in which failure location (cause) is unknown In FIG. 7, in the system operation state as shown in FIG. 2, the node device used as the active node device in one node block fails. It is explanatory drawing of the switching operation when it becomes in a communication impossible state of a place (cause) unknown. As shown in FIG. 7, a case will be described in which the node device 101 used as the active system in the node block 1 having the configuration of FIG. 2 is in the incommunicable state where the failure point (cause) is unknown.

For example, when the node device 101 communicates with another node device 103, the failure location is unknown (see FIG. 7).
Of the node device 101
Outputs the above-mentioned switching instruction signal to the other node device 102 of the node block 1 via the above hard wire (FIG. 7). Node device 102 receiving this
Is the address management table of the own node device Table 6 to Table 7
In addition to updating, the contents of this updated address management table are broadcast from the spare bus (bus B) to other node blocks (in FIG. 7). Receiving this, each node device updates the address management table as shown in Table 7. In this way, all of the node devices and buses having the configuration of FIG. 7 are switched from the active system to the standby system and from the standby system to the active system. In other words, when the communication failure state of the failure location (cause) is unknown, it may be the cause of the communication failure state. Do not use all the node devices and buses that were used as the active system until then. Since the spare node device and bus are switched to be used as the active node device and bus, a LAN system using the spare system is immediately constructed even if the cause of unexplained communication is lost.

[0055]

[Table 6]

[0056]

[Table 7]

Normality Monitoring of Standby System FIG. 8 is an explanatory diagram of the normality monitoring operation of the standby system by the master node device in the steady state. In the configuration of FIG. 2, in a steady state, while the active node devices are communicating via the active bus, as shown in FIG. Using (B), polling data is periodically or non-periodically transmitted (in FIG. 8) to each node device in the standby system, and each standby node device receiving the polling data is normal. By the procedure of responding the data indicating that to the master node device 100 from the standby bus, while the master node device 100 is communicating via the active bus between the active node devices, the master node device 100 And the normality of each spare node device can be monitored.

Second Embodiment (Duplicate Master Node Device)
Reduction) Figure 9 shows a configuration of a second embodiment of LAN system according to the present invention. In FIG. 9, 100-1 and 100-2 are two master node devices for duplication. Each master node device 100-1 and 100-
The configuration of 2 is the same as the master node device 1 of the first embodiment described above.
Same as 00. Although not shown in FIG. 9, two master node devices are connected to each other by hard wires in the same manner as the two node devices of each of the node blocks 1 to 3, and the two master node devices are connected to each other. It can also be configured to be able to detect a device failure occurrence signal, a power-off signal, a switching instruction signal, etc. that are output.

In this case, the address management table provided in each node device including the master node device also has an entry indicating the active and standby addresses of the master node, as shown in Table 8. . This allows
It is possible to identify which master node is the working node or the backup node.

[0060]

[Table 8]

In addition, in the above-described first embodiment, the address management table update information and the like notified to each node device via the master node device 100 is transmitted from the node device as the source on the bus A or B. , And each node device connected to the bus is notified by detecting and receiving the transmission. The communication of the information of the address management table update and the like which does not go through the master node as described above can be performed also in the first embodiment.

Hardware Configuration In the configurations of the first and second embodiments of FIGS. 2 and 9, each node device may be, for example, one personal computer or workstation. The above-described function according to the present invention may be realized by software installed in these personal computers or workstations, or it may be dedicated to a communication unit mounted in these personal computers or workstations. It may be realized by a hardware logic circuit or a processor provided. In particular, the address management table described above can be written and read by the processor even if the register can be set by the hardware logic circuit.
It may be M or EEPROM or the like.

[0063]

As described above, according to the present invention,
There is an effect that the inter-node communication function can be maintained without stopping the system even when an abnormality occurs in the bus or the node device or at the time of maintenance.

[Brief description of drawings]

FIG. 1 is a diagram showing a basic configuration of a LAN system in which a plurality of nodes are connected by a bus according to the present invention.

FIG. 2 is a diagram showing a configuration example of a LAN system in which both nodes and buses are duplicated as a first embodiment of the present invention.

3 is an operation explanatory diagram when a certain node device is started up in the configuration of FIG. 2. FIG.

FIG. 4 is an explanatory diagram of broadcast communication of address management table update information from a master node device to each node device.

FIG. 5 is a failure relief when a failure occurs in a node device used as an active node device in one node block in the system operation state as shown in FIG. 2 and communication is hindered. It is explanatory drawing of a method.

FIG. 6 is a diagram illustrating the operation state of the system as shown in FIG. 2, in which the node device used as the active node device in one node block is disconnected from the currently used bus of the active system. It is explanatory drawing of the switching operation at the time.

7 is a diagram showing a case where a node device used as an active node device in one node block is in an incommunicable state where a failure point (cause) is unknown in the system operation state as shown in FIG. FIG. 6 is an explanatory diagram of a switching operation of FIG.

FIG. 8 is an explanatory diagram of a normality monitoring operation of the standby system by the master node device in a steady state.

FIG. 9 is a diagram showing a configuration of a second embodiment of a LAN system according to the present invention.

[Explanation of symbols]

100, 100-1, 100-2 ... Master node device 101, ... 106 ... Node device 200, 200-1, 200-2, 201, ... 20
6 ... Address management table A, B ... Bus SEL ... Selector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ikuo Taniguchi 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor Junichi Tamura 1015, Kamiodanaka, Nakahara-ku, Kanagawa Prefecture, Fujitsu Limited ( 72) Inventor Akira Yamamori 2-2-6 Jomi, Chuo-ku, Osaka-shi, Osaka In-house, Fujitsu Kansai Digital Technology Co., Ltd. (72) Inventor, Koichi Nara 1015, Kamedotachu, Nakahara-ku, Kawasaki-shi, Kanagawa Within Fujitsu Limited

Claims (13)

[Claims] 1. A LAN system in which a plurality of nodes are connected by a bus, the first and second buses (A, B) for using one of the buses as an active system and the other as a standby system. ), Each of the plurality of nodes has a first and a second node device for using one as an active system and the other as a standby system, and each of the first and second node devices. Has a selective connection means (SEL) for selectively connecting with either one of the first and second buses (A, B), and the selective connection means (SEL) has the first and second Of the second node devices, the node device used as the active system is connected to the bus used as the active system of the first and second buses (A, B), and the standby system is connected. The node device used as LAN system, characterized in that connected to the bus for use as a system. 2. Each of the first and second node devices in each of the plurality of nodes, whether the first and second node devices in the plurality of nodes are used as an active system or a backup The LA according to claim 1, further comprising an active / spare node information holding unit that holds active / spare node information indicating whether or not it is being used as a system.
N system. 3. In each of the plurality of nodes, each of the first and second node devices includes: the active / spare node held by the active / spare node information holding unit in its own node device. When the system node information is updated, the updated working system / spare system node information is transferred to the working system / spare system node information holding means in the other node device of the first and second node devices. Active / spare node information transfer means and the updated active / spare node information transferred by the active / spare node information transfer means in the other node device of the first and second node devices An active / spare node information updater that updates the active / spare node information held by the active / spare node information holding means in its own node device based on the system node information LAN system according to claim 2 having and. 4. Each of the first and second node devices in each of the plurality of nodes, when the node device of itself is an active node device at the time of startup of the respective node, On startup of at least one of the first and second buses, the start-up node information indicating that the node device of is a working node device and the other node device of the node is a standby node device. The start-up node information sending means for sending out and the start-up node information sent from another node is sent on the bus of the first and second buses to which the own node device is connected. Means for detecting that the start-up node information is detected, and a means for inputting the start-up node information when the start-up node information is detected. 3. The LAN system according to claim 2, further comprising means for updating the active / spare node information held by the active / spare node information holding means. 5. Instead of each of the first and second node devices having means for detecting that the start-up node information is transmitted, the bus is provided in addition to the plurality of nodes. A master node, the master node receiving the start-up node information transmitted on at least one of the first and second buses, and the received start-up node information. Is transmitted to each of the first and second node devices of the plurality of nodes via the first and second buses. 6. Each of the first and second node devices in each of the plurality of nodes has a failure in its own node device, and has its node device disconnected from the bus. Of these, means for detecting at least one of them, and when its own node device is the active node device,
If at least one of the occurrence of a failure in its own node device and the disconnection of its own node device is detected, the occurrence of the failure and the disconnection from the bus Means for notifying at least one of the detections to the other node device of the first and second node devices, and the other node device of the first and second node devices is the active node device Sometimes, when the other node device receives at least one of the occurrence of a failure in the other node device and the disconnection from the bus, the active system in its own node device. / The active system held by the standby node information holding means /
Means for updating the spare node information so that its own node device is the active node device, and information indicating that the own node device is the active node device when receiving the notification. Means for sending on at least one of the first and second buses, sending information indicating that the own node device is an active node device, and selecting the device within the own node device. 3. The LAN system according to claim 2, further comprising means for switching connection means (SEL) so as to connect to the working bus among the first and second buses. 7. The bus, in addition to the plurality of nodes,
A master node, the master node receiving information indicating that the node device of its own, which is transmitted onto at least one of the first and second buses, is a node device of an active system; , The received information indicating that the own node device is an active node device is sent to each of the first and second node devices of the plurality of nodes via the first and second buses. The LAN system according to claim 6, comprising means for transmitting. 8. Whether each of the first and second node devices in each of the plurality of nodes uses the first and second buses as an active system or a standby system 3. The LAN system according to claim 2, further comprising a working / standby system bus information holding unit that holds the working / standby system bus information. 9. In each of the plurality of nodes, each of the first and second node devices has: the active / spare system held by the active / spare bus information holding means in its own node device. When the system bus information is updated, the updated working system / spare system bus information is transferred to the working system / spare system bus information holding means in the other node device of the first and second node devices. Active / spare bus information transfer means, and the updated active / spare information transferred by the active / spare bus information transfer means in the other node device of the first and second node devices. 9. An active system / spare system bus information updating unit for updating the active system / spare system bus information held by the active system / spare system bus information holding unit in its own node device according to the system bus information. LAN system described. 10. Each of the first and second node devices in each of the plurality of nodes is configured such that when the node device of its own is used as an active system, Of these, means for detecting that communication via the working bus is disabled, and the other node of the first and second node devices when the communication is detected to be disabled Means for transmitting to the device an instruction for the other node device to switch to the active system; means for receiving the instruction from the other node device of the first and second node devices; When it receives a message, the active / spare node information held by the active / spare node information holding means in its own node device is updated so that its node device is the active node device. Means to do And when the instruction is received, the active / spare bus information held by the active / spare bus information holding means in its own node device is exchanged between the active and standby systems. The information indicating that the node device of its own is the active node device, and the active / spare bus information exchanged between the active system and the standby system, Means for transmitting onto at least one of the second buses, and information indicating that the own node device transmitted onto at least one of the first and second buses is a node device of the active system, Also, the active / spare system bus information exchanged between the active / spare system is received, and the active / spare node information holding means and the active / spare system in its own node device. Of bus information holding means LAN system according to claim 7 having means for updating the contents. 11. The bus has a master node in addition to the plurality of nodes, and the master node is the first node.
And information indicating that the node device of its own is sent to at least one of the second bus and the node device of the active system, and the active system / spare system switched between the active system and the standby system. Means for receiving system bus information, information indicating that the received node device is a node device of an active system, and an active / spare system bus exchanged between the active system and the standby system Information the first
And the first of the plurality of nodes via a second bus
11. The LAN system according to claim 10, further comprising means for transmitting to each of the second node devices. 12. At least one of the plurality of nodes
One is a master node, and each of the first and second node devices of the plurality of nodes is a node device of a standby system connected to the bus of the standby system. A spare system bus between the master node spare system node device and a spare system node device in each node, and a spare system node in each node. The LAN system according to claim 1, further comprising means for performing communication for confirming the normality of the device. 13. The node device according to claim 1.