JPH0713791A - Equalization method for redundant control system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a dual structure for an operating side and a standby side. When a malfunction occurs on the operating side, the programmable side (a PC and a programmable controller) enter the operating state in place of the previously operating side. In a duplicated control system having control devices such as (abbreviated) etc., the present invention relates to an equalization method for keeping all data including programs held by the operating side control device and the standby side control device equal.

[0002]

2. Description of the Related Art FIG. 1 is a system configuration diagram as an embodiment of the present invention. The conventional technique will be described below with reference to this diagram. Incidentally, the means 2A in the figure does not exist conventionally. In FIG. 1, 1 is a PC on the operating side (operating PC), 2 is a PC on the standby side (standby PC), 8 is a control target, and 7 is an input / output interface for the redundant PCs 1 and 2 to the control target 8. An output device, 4 is a management personal computer of the system of FIG. 1, 3 is a redundant PC 1, 2, an input / output device 7,
And a common transmission line for connecting the management personal computer 4 and the like. Further, 6 is provided between the working PC 1 and the standby PC 2, and an equalization transmission line (also referred to as a synchronous bus) as a data transmission line for keeping the data held by both the same at all times (that is, equalization), 5 A loader for storing programs and the like in the PCs 1 and 2.

In FIG. 1, a duplicated PC
The conventional equalization of 1 and 2 is realized by the following procedure. Before operation, the exact same program or definition data is transferred to the active PC 1 and the standby PC 2 from the management personal computer 4 via the transmission path 3 or directly using the loader 5.

When the operation is started, the operating PC 1 exchanges data with the input / output device 7 and controls the controlled object 8. Immediately after the standby operation of the standby PC 2 is started, fixed data is transferred from the active PC 1 to the standby PC 2 using the equalization transmission line 6. After the end, the dynamically changing variable data is transferred from the active PC 1 to the standby PC 2 at regular intervals using the equalization transmission line 6.

The operating PC 1 and the standby PC 2 perform mutual monitoring using the transmission line 3. If the operating PC 1 becomes abnormal and the operating right is abandoned and the standby PC 2 is normal, the standby PC 2 newly switches to the operating side and executes control.

[0006]

However, the above-mentioned duplex control system has the following drawbacks. When changing a program or definition data, the changed program or definition data must be transferred from the management personal computer 4 or the loader 5 to the two PCs 1 and 2 as in the case of the program loading before the operation described above. I won't.

After the abnormality occurs and the switching occurs and the PC on the standby side is replaced, the program or definition data must be transferred to the standby PC again from the management personal computer or the loader. Therefore, the present invention solves the above problems,
It is an object of the present invention to provide an equalization method for a duplicated control system, which can easily change a program or definition data or replace an abnormal PC as well as a control system for one PC in a duplicated control system without being aware of duplication. It is an issue.

[0008]

In order to solve the above-mentioned problems, in the equalization method according to claim 1, a standby side control device (standby PC 2 or the like) and an operating side in which a program and fixed data are stored in advance. Equipped with a control device (operating PC1 etc.),
The operating side control device always controls the controlled object (8 etc.),
The standby-side control device monitors the active-side control device for abnormalities at a predetermined cycle, and at the same time transfers the variable data from itself to the operating-side control device (via the equalization transmission line 6 or the like). Is a redundant control system in which the standby side control device controls the controlled object instead of the operating side control device when the power supply is turned on or reset (the operating side all data copying means 2A, etc.). All data including the program is transferred to itself from the operating side control device.

According to the equalization method of claim 2, claim 1
In the equalization method described in (1), the standby control device does not change the program or fixed data of the working control device (via the working data all-copying means 2A) during the monitoring of the working control device. Is also checked, and if there is this change, the operating side control device is made to transfer all the data including the program to itself.

[0010]

When the standby PC is turned on and reset, and when the program and definition data of the active PC are changed, the standby PC transfers all the data including the program of the active PC to itself before the system starts or When changing the program, it is only necessary to load the program and definition data into the operating PC.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. In the present invention, in FIG. 1, a standby PC
An operating-side all data copying means 2A is provided in 2. The copying means 2A is a partial function part when it is considered that the function part relating to the present invention is shared among the functions of the standby PC 2.

FIG. 2 is a flow chart showing the operation of the standby PC 2 according to the present invention when the power is turned on or reset.
1-110 show the steps. Further, FIG. 3A shows a protocol (communication procedure) for mutual monitoring between the PCs 1 and 2, and FIG. 3B is a flowchart of an operation for confirming whether or not the standby PC 2 has moved the operating right based on this mutual monitoring. Three
01 to 305 indicate the steps.

Next, FIG. 2 will be described. When the power of the standby PC 2 is turned on during the normal operation of the working PC 1, the standby PC 2
Determines in steps 101 to 103 that it is the standby side control device of the duplex system. That is, the standby PC 2 first performs initialization (101), and then checks whether or not the equalization transmission line 6 as a synchronous bus exists (102). If it does not exist (branch N), it operates as an independent control device. It operates (109). However, if the equalization transmission line 6 exists in step 102 (branch Y), it is checked whether or not there is an active PC 1 (103). If the active PC 1 does not exist (branch N), the device itself operates as the operating side control device (108), but if the active PC 1 exists (103, branch Y), the device itself becomes the standby side control device. Confirm that there is. Then, by using the message communication function of the equalization transmission line 6, data transfer is requested to the operating PC 1 (10
4), receive all data including the program and definition data (105, 106). Then, when reception of all data is completed (106, branch Y), the operation state as the standby side control device of the duplex system is entered (107).

As shown in FIG. 3 (A), the mutual monitoring between the active PC 1 and the standby PC 2 is such that the active PC 1 performs the operation right confirmation transmission 9 via the transmission line 3, while the standby PC 2 similarly transmits the transmission line 3 to the standby PC 2. This is realized by performing the operation right confirmation response transmission 10 via. This allows the active PC 1 and the standby PC 2 to know each other's existence and state.

When a change in the program or definition data on the operating PC 1 side is also added to this transmission, the standby PC
2 can know. That is, as shown in FIG. 3B, the standby PC 2 at this time analyzes the transmission data of the operation right confirmation 9 from the operation PC 1. When it is determined by this analysis that the operating PC 1 has abandoned the operating right (301, branch Y), a response indicating that the operating right is acquired is activated for the confirmation response 10 in FIG. 3A (302). , Starts operation as an operating side control device instead of the operating PC 1 (304).

On the other hand, when it is determined in step 301 that the operating right is not abandoned (branch N), a response indicating that the operating right is not abandoned is activated for confirmation response 10 (303),
Further, it is checked whether or not there is a change in the program or definition data on the active PC 1 side (that is, a status change of the active PC 1) (305), and if a status change of the active PC 1 is detected here (branch Y), the step of FIG. Moved to 104 and operating PC
1 is requested to transfer all data. As a result, the program / definition data becomes the same as the working PC 1.

The operating side all data copying means 2A of FIG.
2 corresponds to steps 104 to 106 in FIG. 2 and step 305 in FIG.

[0018]

According to the present invention, at the time of power-on or reset, if the control unit (PC) determines that it is the standby side control unit of the duplex system, all the data including the program is copied from the operating side. Therefore, at the time of duplex startup, after storing the program and definition data only on the operating side, all the data stored on the operating side is copied to the standby side by simply turning on the power on the standby side, and waiting as in the past. There is no need to manually store the same program and definition data on the operating side, and there is an effect that the duplication startup and PC replacement work are simplified.

In the mutual monitoring operation of the redundant system,
Since the operating side notifies the standby side of whether the program or definition data has been changed, and when there is a change, the standby side copies the entire data area of the operating side from itself, so it is necessary to change the program or definition data. When performing this, it is only necessary to perform this change work on the operating side, and the change work can be performed without being aware of duplication.

[Brief description of drawings]

FIG. 1 is a system configuration diagram as an embodiment of the present invention.

FIG. 2 is a flowchart showing a main part of a process when the power of the control device is turned on or reset.

FIG. 3 is a flow chart showing a transmission procedure of mutual monitoring between the redundant control devices and a procedure of an operation right transfer confirmation operation of the standby control device.

[Explanation of symbols]

 1 Operating side program controller (operating PC) 2 Standby side program controller (standby PC) 2A Operating side all data copying means 3 Transmission line 4 Management personal computer 5 Loader 6 Equalization transmission line 7 Input / output device 8 Control target

Claims (2)

[Claims] 1. A standby-side control device, and an operating-side control device in which a program and fixed data are stored in advance. The operating-side control device controls a controlled object at all times, and the standby-side control device operates at a predetermined cycle. The controller on the operating side monitors whether or not there is an error, and the variable data is transferred from itself to the controller on the operating side. When the controller on the operating side has an error, the standby controller controls the controlled object on behalf of the operating controller. In the redundant control system, the standby-side control device transfers all the data including the program from itself to the self-control device at the time of power-on and reset of the standby-side control device. Valuation method. 2. The equalization method according to claim 1, wherein the standby-side control device also checks whether or not a program or fixed data of the operating-side control device is changed during the monitoring of the operating-side control device. When there is this change, the equalization method for the dual control system is characterized in that all data including the program is transferred from the operating side control device to itself.