JPS5814201A - Bumpless backup device for sequence controller - Google Patents

Abstract

PURPOSE:To prevent system down with a simple constitution, by performing the control with a backup sequence controller based on data at normal operation stored at the inside of a bus switching device if the sequence controller is in failure. CONSTITUTION:At normal operation, switches 30, 40 and 50 in a bus switching device 5 are all connected to the position A and the control is performed with a central operation processor 1, a storage device 3, the bus switching device 5, a storage device 10 storing data on the way of the operation provided in the device 5, and an input/output device 6. If any failure takes place in the processor 1 or the storage device 3, the switches 30, 40 and 50 in the device 5 are connected to the B position. Then, the control of the input/output device 6 can be continued without system down by the processor 2 and the storage device 4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides the following advantages:
This invention relates to a pump press backup device for a sequence controller that continues control without stopping the system.

Conventionally, sequences and controls have been performed using relays with contacts. For example, when opening a valve only when all various conditions are met, each condition is replaced with 0N10FF relay contacts, or control is performed by a range control. Therefore, if a failure occurred in such a device, it was sufficient to replace the failed relay. But today,
In this way, the above-mentioned sequence controller is used for FT11 control, and the relay sequence is replaced by software, a sequence program that runs. Once a failure occurs, the entire control device will stop, not just one relay as in the case of using a relay. For this reason, a breadpress backup system is required in which when one sequence controller fails, the system can be switched to another backup sequence controller Iζ to continue control without stopping the system.

-ff The sequence controller consists of a central processing unit that executes sequence instructions, a sequence program assembled with sequence instructions, a storage device that holds data during operations, and an input/output device that communicates with the outside. , can be broadly classified. When configuring a bumpless pack amplifier system, two sets of these three devices are provided, the same sequence program is written in both storage devices, and the two sets of central processing units perform the same processing. Then, the input from the outside is inputted to two sets of central processing units in the same way, and the output to the outside is from one of the 82 sets of central processing units (the output from both central processing units is the same).
[If one device is connected and one central processing unit or storage device fails, those devices are disconnected by the input/output processing device, and the other normal central processing unit and By continuing control only with the storage device, bumpless backup without stopping the system is possible.

However, this method had the disadvantages of the trouble of operating two sets of central processing units in synchronization, the complexity of the input/output processing unit, and the tendency to become expensive as the scale of input/output increased. .

In consideration of these points, the present invention switches to a backup sequence controller and stops the system so that even if one sequence controller fails, the failure does not cause a fatal failure of the system to which the sequence controller is applied. To provide a pump press backup device for a sequence controller that continues control without any trouble, with a simple configuration and at low cost.

Hereinafter, the present invention will be explained with reference to the drawings. FIG. 1 shows an embodiment of the present invention, in which central processing units 1 and 2 are connected to storage devices 3 and 4 through a memory bus 200, respectively. Further, through the same memory bus 200, the bus switching device 5 is connected to two storage devices 10 and 20 for holding data in the middle of calculations, and one
/ 0 × 100 s It is coupled to the input/output device 6 through the hash switching device 5 . During normal operation, all internal switches 30, 40, and 50 of the bus switching device are set to A.
The central processing unit ff, the storage device 3. Control is performed by a bus switching device 5, a storage device 10 provided therein for holding data in the middle of calculations, and an input/output device 6.

In general, a sequence controller repeatedly executes a sequence program A made up of sequence commands to several milliliters at a high speed of several lQms. In this case, the sequence program held in the storage device 3 is repeatedly executed, and after each execution, it is checked whether there is any failure (). Copy additionally. Therefore, the storage device d20 always holds normal data.

If any failure is discovered in the central processing unit or the storage device 3 in this state, the path switching device 5
The switches 30, 40, and 5Q inside are all B
connected to the side. Then, based on the normal data held in the storage device, the central processing unit 2 and storage device 4 can be used to operate the human blade device 6 without stopping the system.
Continue to control.

Fig. 2 shows another embodiment of the present invention, and 11 In Fig. 1, one sequence controller is backed up, whereas in this embodiment, two or more sequence controllers are backed up. It is. That is, a central processing unit 1, a storage device 3, a path switching device 5. A backup sequence controller consisting of a central processing unit 12 and a storage device +14 is used to control each sequence for a sequence controller consisting of an input/output device 6 and two or more sequence controllers having the same configuration. The controller is coupled via a switching device.

In the above configuration, the internal operation of the path switching device during normal operation is the same as in the case of FIG. 1, and each sequence controller is operated independently. If a failure is discovered in any one of the sequence controllers, all the corresponding switches in the path switching device are connected to the BII. Then, based on the normal data held inside the path switching device, the backup sequence controller continues operation without stopping the system.

In this case, the storage device 4 of the backup sequence controller includes sequence controllers backed up in advance,
It is necessary to hold the same sequence program as the sequence program written in the controllers for the number of controllers, except in cases where the respective programs are all the same. Further, it is not possible to connect two or more switches in the path switching device to the B connection at the same time.

As described above, according to the present invention, the central processing unit and the storage device can be easily disconnected and connected with a simple configuration, and even if the sequence controller fails, control can be continued without stopping the system. It is possible to provide a pumpless backup device for a sequence controller.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing another embodiment of the present invention. 1.2.11... Central processing unit, 3.4.13... Storage device,
5.15......Path switching device,
6.16 Input/output device, 10.
2)・・・・・・・・・Storage device, (9), 40
,50......Switch, 100...
・・・・・・・・・・・・Memory path 1200・・・・・・
...I10 pass. (7317) Representative Patent Attorney Karasuke Norichika (and 1 other person) No. 1
Figure 2

Claims (1)

[Claims] A central processing unit that executes sequence instructions; a storage unit that is connected to the central processing unit through a memory path and holds a sequence program composed of sequence instructions; and an external unit that is connected to the central processing unit through an input/output path. In the sequence controller, a path switching device is provided between the central processing unit, the storage device, and the input/output device, and this path switching device allows the central Two sets of storage devices f are provided, one of which is connected to another backup sequence controller consisting of an arithmetic processing unit and a storage device, and one of which is connected to the sequence controller, and which holds data during the calculation inside the path switching device. , and the other is a breadpress backup device for a sequence controller, which is connected to periodically copy data held in one of the storage devices.