JP2636610B2 - Backup method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a controller backup system in a control system used for general industry, for example.

[0002]

2. Description of the Related Art FIG.
FIG. 1 is a configuration diagram illustrating a conventional control system disclosed in Japanese Unexamined Patent Publication (Kokai) No. H10-15095. In the figure, 1 is a LAN (Local Area)
Network, transmission line 2, upper computer having auxiliary storage medium 3, 41 to 45 are stations on LAN 1 having station addresses # 1 to # 5, respectively, 6
Reference numerals 2, 64, and 65 denote controllers that perform independent control, 61 denotes a backup controller installed on the LAN 1, 51, 52, 54, and 55 denote controllers 61, 62, 64, and 65, and the stations 41, 42, and, respectively. 44, 45 interface devices, 8
2, 84, 85 are process input / output devices provided corresponding to the controllers 62, 64, 65;
Reference numeral 75 denotes a switching device, and reference numerals 92, 94, and 95 denote bypass routes for bypassing when the controllers 62, 64, and 65 cannot operate normally due to a failure or the like.

Next, the operation will be described. The auxiliary storage device 3 of the host computer 2 stores control programs for all controllers connected to the LAN transmission line 1. It is also assumed that the host computer 2 periodically performs failure diagnosis of all controllers connected on the LAN transmission line 1. Now, a failure occurs in the controller 62, and the backup operation of the controller 62 is
A case where the backup-dedicated controller 61 attempts to perform the operation will be described. The failure of the controller 62 is detected by the host computer 2 by performing a periodic failure diagnosis on all controllers of the host computer 2. Controller 62 determined to be faulty by host computer 2
Is disconnected from the LAN transmission line 1 (the interface device 52 and the switching device 72 operate according to commands from the host computer), and the process input / output device 82 controlled by the controller 62 is directly connected to the LAN. Next, the control program of the controller 62 stored in the auxiliary storage device 3 of the host computer 2 is transferred to the backup controller 61 by the host computer 2 via the LAN transmission line 1, and the controller 61 Start backup operation.

[0004] Next, a case will be described in which the failure controller 62 is detected to have recovered from the periodic failure diagnosis of the host computer 2 and the backup controller 61 stops the backup operation of the controller 62. When the host computer 2 detects that the controller 62 has returned, the host computer 2
2, the transfer of the control program of the controller 62 stored in the auxiliary storage device 3 of the host computer 2 is started, and the controller 62 is started up. When the controller 62 starts up, the backup operation stop command of the backup controller 61 is sent to the controller 61.
To stop the backup operation. Further, the interface device 52 and the switching device 72 are switched to a state at the time of normal controller operation in accordance with a command from the host computer 2. Finally, a command to start operation of the restored controller 62 is sent from the host computer 2 to the controller 62 to return to the original operation state.

[0005]

Since the backup method in the conventional control system is performed as described above, if the host computer 2 that diagnoses each controller fails, it is possible to detect an abnormality of the controller. And the backup system does not work. Further, since the backup controller is fixed, it is necessary to connect a plurality of backup controllers to realize N: N backup, which increases the cost. There were issues such as.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and eliminates the need for a diagnostic function of each controller by a host computer. By having each station on the LAN, the time required for the backup operation can be reduced, and a dedicated backup controller is not particularly required, so that an N: N backup system can be constructed. It is an object of the present invention to obtain a backup method having such advantages.

[0007]

A backup system according to the present invention comprises a plurality of stations connected to a LAN, a plurality of controllers respectively connected to these stations for controlling a process input / output device, and a controller for these controllers. Storage means for storing the control program of each controller, means for cyclically transmitting the control program of each controller stored in the storage apparatus via the LAN, and failure diagnosis of the controller provided in each station and connected to its own station Means for registering which controller is provided in each of the above controllers and which backup is performed by its own controller in the event of failure of any other controller. Release from LAN and other Means for notifying the failed controller, the controller registered to back up the notified failed controller takes in the control program of the failed controller among the control programs transmitted cyclically, and controls the failed controller. The backup control of the input / output device control is performed.

[0008]

According to the present invention, the backup method is LAN
Each station has a function to diagnose the failure of the controller connected to itself and report the status of the controller connected to the own station to other stations connected to the LAN. In addition to detecting the failure state of other controllers, other controllers to be backed up in each controller are defined, and the control programs of all the controllers stored in the storage device are transmitted using the cyclic transmission function of the LAN. By transmitting to the transmission path, the controller defined as the backup controller
The control program of the failed controller can be obtained, and the backup operation can be performed on any controller immediately when the controller to be backed up fails.

[0009]

【Example】

Embodiment 1 FIG. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a LAN (Local Area).
a network), 2 is an upper computer having an auxiliary storage device 3, 41 to 45 are stations on the LAN 1 having station addresses # 1 to # 5, and 61, 62, 64, and 65 are independent control units. , 51, 52, 54, 55
Are interface devices for the controllers 61, 62, 64, 65 and the stations 41, 42, 44, 45, respectively. 81, 82, 84, 85 are processes provided corresponding to the controllers 61, 62, 64, 65, respectively. I / O devices, 71, 72, 74, 75 are switching devices,
91, 92, 94, and 95 are controllers 61, 62,
64 and 65 are bypass routes for bypassing when normal operation cannot be performed due to a failure or the like.

Next, the operation will be described. The auxiliary storage device 3 of the host computer 2 stores a control program that operates on all controllers such as the controllers 61, 62, 64, and 65 connected to the LAN transmission line 1.
Further, as a transmission function of the LAN 1, a cyclic transmission function is supported, and each station 41, 42, 4
3, 44, and 45. Using this cyclic transmission function, the control program of all the controllers is periodically transmitted from the station 43 to all the stations on the LAN. On the other hand, the stations 41, 42, 43, 44, 4 connected on the LAN transmission line 1
5 and the like periodically perform fault diagnosis of the controllers 61, 62, 64 and 65 connected to their own stations, hold the results in their own stations, and transmit the results to all the stations connected to the LAN 1. Report regularly. As a result, any station connected to the LAN 1 can sequentially know the failure status of all the controllers connected to the LAN 1. Here, FIG. 5 shows the LAN held by an arbitrary station.
An example of a table format for setting the failure status of all the controllers connected above is shown. In FIG.
An existence flag indicating whether or not a station exists on the LAN 1, a maximum sequence number when a control program of a controller connected to an arbitrary station is cyclically transmitted, and a backup controller of the controller connected to the arbitrary station. The station address is stored.

Hereinafter, the controller 61 causes an abnormality,
FIG. 4 shows a case where the controller 64 performs backup.
A description will be given based on the flowchart of FIG. In FIG.
It is assumed that the controller 61 has caused an abnormality, and the abnormality has been detected in the failure diagnosis of the controller 61 of the station 41 (step S1).
The other station that has detected the abnormality of No. 1 checks the failed station address and the station address of the backup controller (step S2). The controller 64 defined as the backup controller of the controller 61 in the table of FIG. 5 checks whether or not the controller 64 is the backup controller of the failed controller 61 (step S3).
Recognizing that this is the backup controller of the first, so that it can operate as a backup controller,
The control program of the fault controller 61 is received and stored from among the control programs constantly transmitted cyclically from the host computer connected to the station 43 (step S4). The reception is completed when there is no longer a comparison error between the data received last time and the data received this time. On the other hand, if it is determined that the controller 61 has failed, the interface device 51 and the switching device 71 operate, and the failed controller 61 is disconnected from the station 41,
Through the bypass route 91, the process input / output device 81
Are directly connected to the LAN transmission line 1 via the station 41. In this way, control of the process input / output device 81 connected to the station 41 is undertaken by the backup controller 64. As a matter of course, the controller 64 also performs control of the process input / output device 84 continuously.

Next, the case where the failure controller 61 returns will be described. The backup controller 64
Even during the backup operation, confirmation of the return of the controller 61 is always performed (step S5). When the restoration of the failed controller 61 is confirmed (step S6), the controller 61, which has returned, checks whether its own control program has been completely received by cyclic transmission from the host computer (step S7). When the reception completion is confirmed (step S8), the interface device 5
1 and the switching device 71 operate, and the controller 61
Is connected to the station 41. Thereafter, the backup controller 64 stops the backup operation of the controller 61 (Step S9), and deletes the control program of the controller 61 from the controller 64.

Embodiment 2 FIG. It should be noted that in the first embodiment. Here, the controller 61 and the process input / output device 81 and 84 respectively correspond to the process input / output device 81 in a 1: 1 ratio.
In the example shown above, the initial control was performed.
The same effect can be obtained in a case as shown in FIG. 2 in which one controller controls the same process input / output device or a plurality of process input / output devices. When a system as shown in FIG. 2 is set, even if an arbitrary controller fails, the controller defined as the backup controller in the table of FIG. A backup operation is started in the same manner as described above. When the failed controller returns further, the first embodiment is also performed. The backup controller stops the backup operation according to the same sequence as described above.

Embodiment 3 FIG. Also, in the first embodiment. In the above, in the state where the control programs of the controllers 61, 62, 64, and 65 are all stored in the auxiliary storage device 3 of the host computer 2 and the cyclic transmission is constantly operating, a failure occurs in any controller. When the controller to be backed up receives the control program of the failed controller by the cyclic transmission of the LAN 1 when the failure occurs, the failure of the arbitrary controller is detected by L.
When each of the stations 41 to 45 on the AN 1 detects the station 43, the station 43 to which the host computer 2 is connected
Starts the cyclic transmission and stops the cyclic transmission after a lapse of sufficient time for the backup controller to complete the cyclic reception. Further, the auxiliary storage device 3 is connected to the LAN 1
Needless to say, a storage device directly connected to the storage device may be used.

[0015]

As described above, according to the present invention, the diagnosis function of the host computer in the conventional backup system is configured to be provided to each station on the LAN, and the backup controller is not fixed but connected to the LAN. Since all the connected controllers are configured to be operable as backup controllers, the controller diagnosis function of the host computer is not required, and the backup operation is not affected even when the host computer is abnormal.
Since each station has the above, the time required for the backup operation can be shortened, and a dedicated backup controller is not particularly required, so that an N: N backup system can be constructed.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of the present invention. FIG. 2 is a block diagram showing a control system for realizing a backup method according to the first embodiment.

FIG. 2 shows a second embodiment of the present invention. FIG. 2 is a block diagram showing a control system for realizing a backup method according to the first embodiment.

FIG. 3 is a block diagram showing a conventional backup type control system.

FIG. 4 shows a first embodiment of the present invention. 5 is a flowchart showing an operation flow of an arbitrary backup controller according to the first embodiment.

FIG. 5 is a first embodiment of the present invention. FIG. 7 is an explanatory diagram showing an example of a diagnostic table format of a controller held at an arbitrary station on a LAN according to the first embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 LAN transmission line 2 host computer 3 auxiliary storage device 41 station 42 station 43 station 44 station 45 station 51 interface device 52 interface device 54 interface device 55 interface device 61 control controller 62 control controller 64 control controller 65 control controller 71 Switching device 72 Switching device 74 Switching device 75 Switching device 81 Process input / output device 82 Process input / output device 84 Process input / output device 85 Process input / output device

Claims (1)

(57) [Claims] 1. A plurality of stations connected to a LAN, a plurality of controllers respectively connected to the stations for controlling a process input / output device, a storage device storing a control program for these controllers, and a storage device for storing the control program. Means for cyclically transmitting the control program of each controller stored in the device via the LAN, means for diagnosing a failure of the controller connected to the own station provided at each station, and means provided for each controller. Means for registering which controller is to be backed up by its own controller in the event of a failure, and means for disconnecting the failed controller from the LAN and notifying other controllers when a failure of the controller is detected in any of the stations. Has been notified The controller registered to back up the failed controller fetches the control program of the failed controller from among the cyclically transmitted control programs, and performs backup control of the control of the input / output device controlled by the failed controller. Backup method.