JPH01134633A - Controlling method for duplicated controller - Google Patents

Abstract

PURPOSE:To receive input data, to execute the same processing and to prevent the shock of the switching of a duplicated control even at a standby side by connecting two control devices to share an input device, executing the supervision of a transmission line, detecting the abnormality of control devices and executing the switching from the standby side to the control side. CONSTITUTION:Control devices 2' and 3' are connected to an input output device 1 by a transmission line 4' and the connection constitution to share the device 1 is executed. The control device 2' is made into a control side, the control device 3' is made into a standby side, and by the transmitting invitation instruction to the device 1 of the transmitting control part of the control device 2', the transmitting control part of the control device 3' executes the machine only to receive simultaneously the input data transmitted to the control device 2' by the device 1. Based on the input data, the control device 3' executes the same operation as the control device 2' and an arithmetic result is not transferred to the device 1. On the other hand, the supervising part of the control device 3' supervises the receiving instruction of the transmitting instruction arithmetic result of the input data between the device 1 and the control device 2', and when the abnormality occurs at the control device 2', informs the transmitting control part.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a redundant control device using a redundant system method using two control devices that share input/output devices, and particularly to a redundant control device that automatically switches a redundant system. This invention relates to a control method for a duplex control device.

[Prior art]

In general, it would be expensive to realize control system multiplexing itself, and it would be unreasonable to apply control system multiplexing to large-scale input/output devices. The one shown in the figure is used.

FIG. 3 shows a system outline of a conventional redundant control device, in which 1 is an input/output device, 2 and 3 are control devices, 4 is a transmission path, and 5 is a switch.

That is, a switch 5 for selecting one of the control devices 2 and 3 is provided in front of the input/output device 1, and the transmission line 4 is switched by the switch 5.

When the control device 2 has the control right, by using an automatic follow-up device (not shown), the standby control device 3 can control the control device 2 with respect to the control device having the control right.
When a failure occurs in the control device 2 in such a state, a failure signal generated from the control device 2 is given to the switch 5, and the switch 5 is activated and the control device A shockless switching from the control device 2 to the control device 3 is performed, and subsequent control can be continued by the control device 3.

[Problem that the invention seeks to solve]

However, the conventional duplex control device using the control method shown in FIG. 3 has the following problems. That is, (1) it is difficult to completely detect a failure in the control device 2.3, and therefore, even if the control device fails, if a failure signal is not given to the switch, the system will go down.

(2) The switch itself has the risk of poor contact or non-operation.

(3) Furthermore, there is a possibility that the automatic follow-up device may break down, and in such a case, if a switching command is sent out, there will be a large shock to the control system, and there is a risk that the system will go down.

[Means for solving problems]

In view of the above-mentioned points, the present invention has a system in which each control device has a diagnostic means for monitoring the operation of the transmission path, and also connects each control device to the transmission path so that the input/output device is shared. It has the function of allowing both the control side and standby side control devices to receive input from the output device, performs control calculations regardless of the presence or absence of control authority, and suppresses only the output to the standby side input/output device. The present invention provides a control method that can realize an exceptional device.

[For production]

Therefore, in the present invention, since both the control side control device and the standby side control device perform control calculations based on the same setting values and parameters and input from the same input/output device, the control side control device receives input from the same input/output device. When data is input from the output device, the standby control device also inputs data at the same time.

Further, the diagnostic means included in each control device also functions to suppress output of the calculation result by the standby side control device to the input/output device.

Hereinafter, the present invention will be explained in detail based on the drawings.

〔Example〕

1 and 2 are shown to facilitate understanding of the basic concept of the present invention, and t21 and 3/ are control devices. In the figure, the same reference numerals as in FIG. 3 indicate parts having the same function. Here, control devices 2' and 3'
are each equipped with a transmission control unit OTR and a monitoring unit SPv, each of which introduces a transmission path 4'.

That is, the control devices 2' and 3' are connected to one input/output device 1 through a transmission line 4', forming a connection configuration in which the input/output device f1 is shared. Furthermore, the control device τ, 3' has a transmission line 4 inside.
', it has a transmission control unit OTR for performing data transmission with the input/output device 1, and a monitoring unit SPY for detecting whether data transmission is being performed. The function of such a configuration will now be described in detail with reference to FIG.

Here, a case will be explained in which the control device 2' is on the control side and the control device 3' is on the standby side.

Now, the transmission control section of the control device R2' controls data transmission with the input/output device 1 via the transmission line 4'.

This data transmission is performed using a predetermined data transmission control procedure, but the main functions are to instruct the input/output device to send the input data to the control device 2', process the input data, and process the input data to the input/output device 1. This is an instruction to receive the calculation results of the control device 2'.

The transmission control section of the control device 3' is configured to simultaneously receive the input data that the input/output device 1 is transmitting to the control device 2' in response to a transmission invitation instruction to the input/output device of the transmission control section of the control device 2'. Execute only. Based on this input data, the control device 3' performs the same calculation as the control device 2'. Here, the calculation results of the control device 3' are not transmitted to the input/output device 1 because the control device 3' is on the standby side.

On the other hand, the monitoring unit of the control device 3' monitors the input data transmission invitation instruction or the calculation result reception instruction performed between the control device f2' and the input/output device 1, and waits for a predetermined period of time to pass. However, if these transmission solicitation instructions and reception instructions are not detected, it is determined that an abnormality has occurred in the control unit fIt, 2' and data transmission with the input/output device 1 is no longer possible, and the control unit 3' is The abnormality of the control device 2' is notified to the transmission control section.

The transmission control section of the control device 3' is connected to the control device 2 upstream of the monitoring section.
When notified of an abnormality, the system immediately shifts from the standby side to the control side.
Via the transmission path 4', the input/output device 1 is instructed to invite the input data to be sent and to receive the calculation results of the control device 3'.

In this way, the control device 3' can detect an abnormality in the control device 2' in the control devices 2' and 3', and furthermore, the control device 3' can be automatically switched from the standby side to the control side. Furthermore, it is clear that even if the control device 3' is on the control side and the control device τ is on the standby side, switching can be performed in the same way.

Note that since the control devices 2' and 3' perform the switching function as described above and can prevent shocks during switching, it goes without saying that no special hardware is required.

〔Effect of the invention〕

As explained above, ζζAccording to the present invention, by connecting two control devices that share an input/output device and monitoring their transmission paths, it is possible to reliably detect an abnormality in the control device, and from the standby side. By executing the switch to the control side, receiving input data on the standby side, and performing the same exercises as the control side, it is possible to provide a useful control method for a redundant control device that can prevent the shock of the switch. .

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the basic concept of the present invention, FIG. 2 is an operation flow diagram shown to explain FIG. 1, and FIG. 3 is a system outline diagram showing a conventional example. 1...Input/output device, 2, 3, 2', 3
'...Control device, 4.4' Old transmission line.

Claims (1)

[Claims] Two control devices that share an input/output device, each of the two control devices is equipped with a diagnostic means for monitoring the operation of a transmission path, and one is provided as a control side control device and the other as a standby side control device. , when the control side control device inputs data from the input/output device, the standby side control device simultaneously reads the data and performs the same calculation, and each time the calculation is completed, the control side control device inputs the calculation result via the transmission path. By diagnosing whether or not data is being output to the output device,
When the control side control device is not outputting data to the input/output device, the control right of the transmission path is automatically acquired, and the calculation result of the standby side control device is sent as data to the input/output device via the transmission path. A control method for a redundant control device, characterized in that the control device outputs an output.