JP3327455B2 - Redundant controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual control device for appropriately switching between a driving side and a standby side to improve reliability, and more particularly to an improvement for minimizing a communication load between a driving side apparatus and a standby side apparatus.

[0002]

2. Description of the Related Art The present applicant has disclosed, for example, Japanese Patent Application Laid-Open No. 3-2697.
No. 45, Japanese Unexamined Patent Publication No. 4-171538, and the like propose a duplex control device suitable for use in process control and the like. In such a conventional redundant control device, communication between the first processor card 10 and the second processor card 20 is performed using two backboard buses. Each processor card is housed in a housing,
Which of the two backboard buses to use is initially set in advance according to whether the housing position inside the housing is the left slot or the right slot. Such initialization is performed to prevent communication collision occurring on the backboard bus in the communication between the processor cards and to reduce the communication load between the processor cards.

[0003]

However, if an error occurs on one side of the backboard bus and communication becomes impossible, the following problem occurs. That is, in the processor card in which the backboard bus on which the abnormality has occurred is initially set, when communicating with the partner processor card, first, the communication is performed using the backboard bus on the side on which the abnormality has occurred, and communication failure occurs. Then, the backup function performs communication using the other backboard bus to secure communication. Then, there is a problem that a communication failure dead time occurs and a communication load between the processor cards increases. When the communication load increases, there is a secondary problem that the processing capacity of the processor must be reduced in order to secure communication. The present invention has solved the above-mentioned problems, and has improved communication between processor cards.
To prevent communication collisions occurring on the backboard bus,
It is an object of the present invention to provide a redundant control device capable of suppressing an increase in a communication load between processor cards even when an error occurs on one side of a backboard bus and communication becomes impossible.

[0004]

SUMMARY OF THE INVENTION The present invention, which achieves the above objects, is interconnected by a duplicated backboard bus.
Backboard that is used preferentially according to the mounting position.
First and second processor cards on which a memory bus is set
And for these first and second processor cards ,
Set information on which backboard bus should be selected
A backboard bus register, a backboard bus diagnostic unit for diagnosing whether or not each of the duplexed backboard buses can communicate when a processor card of the own station communicates with a partner processor card; When any of the backboard buses is diagnosed as normal by the backboard bus diagnostic unit, different backboard buses are respectively selected for the first and second processor cards in the backboard bus register. Setting the information, and when it is diagnosed that only one of the backboard buses is normal, a backboard bus designation setting unit for setting information for selecting the normal backboard bus in the backboard bus register; , Is provided.

According to the configuration of the present invention, the backboard bus diagnosis unit diagnoses whether each of the duplexed backboard buses can communicate. The backboard bus designation setting unit determines the backboard bus on the side where the communication load is optimal for each processor card,
It is set in the register. Therefore, a quick response is made as compared with a case in which each processor card recognizes that communication is impossible along with the communication and then switches to the other backboard bus to take measures.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a redundant control device to which the present invention is applied. In the figure, duplicated backboard buses ENBUS-1 and ENBUS-2 connect the first processor card 10 and the second processor card 20. The backboard bus registers ENSEL1 and ENSEL2 are provided in the first and second processor cards 10 and 20, respectively, and set the backboard bus to be used preferentially. Here, “use preferentially” refers to the backboard bus /
The side specified by the register ENSEL is used first, and if there is any inconvenience such as communication failure on the specified side, the backboard bus switching unit switches to the other backboard bus.

The backboard bus diagnostic units 12 and 22 diagnose whether or not each of the duplicated backboard buses can communicate when the processor card of the local station communicates with the partner processor card. The backboard bus designation setting units 14 and 24 include the backboard bus diagnosis unit 12 and
22, when both backboard buses are diagnosed as normal, the first processor card 10 and the second processor card 2 are stored in the backboard bus registers ENSEL1 and ENSEL2.
Set a different backboard bus for each 0.

When only one of the backboard buses is diagnosed to be normal by the backboard bus diagnostic sections 12 and 22, the backboard bus registers ENSEL1 and ENSEL2 are checked.
Set the normal backboard bus to. When both backboard buses are diagnosed as faulty by the backboard bus diagnostic units 12 and 22, the backboard bus register EN
One of the backboard buses is set to SEL1 and SEL2. If both backboard buses are out of order, communication between the first processor card 10 and the second processor card 20 is not possible. The result is identical.

The backboard bus switching units 16 and 26 connect their own processor cards 10 and 20 to one of the backboard buses ENBUS-1 and ENBUS-2 according to the settings of the backboard bus registers ENSEL1 and ENSEL2.

Next, the operation of the above-configured device will be described. FIG. 2 is a diagram for explaining the data flow of the apparatus of FIG. 1, and FIG. 3 is a flowchart for explaining the operation of the backboard bus diagnostic unit. The backboard bus diagnostic unit 12 stores the backboard bus E in the backboard bus register ENSEL1.
NBUS-1 is set (S10). Next, communication is performed with the second processor card 20 that is the other party (S12). And backboard bus ENBUS-1
(S14). Subsequently, the backboard bus diagnostic unit 12 stores the backboard bus ENBU in the backboard bus register ENSEL1.
S-2 is set (S16). Next, communication is performed with respect to the second processor card 20, which is the other party (S1).
8). Then, an error state during communication on the backboard bus ENBUS-2 is stored (S20).

Similarly, the backboard bus diagnostic unit 22
Also sets the backboard buses ENBUS-1 and ENBUS-2 in the backboard bus register ENSEL2, executes communication with the first processor card 10, which is the partner, and saves an error state during communication. Using the stored result, the backboard bus designation setting unit sets the backboard bus E
Recognizing whether the NBUS-1 or NBUS-2 is normal or abnormal, information on which backboard bus should be selected is set in the backboard bus register ENSEL.

FIG. 4 shows a backboard bus designation setting unit 1.
4 is a flowchart for explaining operations of Nos. 4 and 24. First, it is determined whether the processor card of the own station is mounted on the right side of the housing slot (S30). If mounted on the right side, it is checked whether an error has occurred on the backboard bus ENBUS-2 (S32). If an error has occurred, the backboard bus ENBUS- is stored in the backboard bus register ENSEL.
1 is set (S36). If an error has not occurred, it is checked whether an error has occurred on the backboard bus ENBUS-1 (S34). If an error has occurred, the backboard bus ENBUS-2 is set in the backboard bus register ENSEL ( If no error has occurred, the backboard bus ENBUS-1 is set to the backboard bus register ENSEL (S3).
6).

If mounted on the left side, the backboard bus EN
Check whether an error has occurred in BUS-1 (S40).
If an error has occurred, backboard bus register E
The backboard bus ENBUS-2 is set to NSEL (S44). If no error has occurred, it is checked whether an error has occurred on the backboard bus ENBUS-2 (S42). If an error has occurred, the backboard bus ENBUS- is stored in the backboard bus register ENSEL.
1 is set (S46), and if no error has occurred,
The backboard bus ENBUS-2 is set in the backboard bus register ENSEL (S44). It is preferable that the diagnosis of the backboard bus by such a backboard bus diagnosis unit be performed at a constant period, for example, every one second. Thus, the backboard bus ENBUS-
If both 1 and 2 are normal, right-side mounted processor car
Back to the backboard bus register ENSEL
Set the board bus ENBUS-1 and set the process
Backboard bus register ENSEL
Is set to the backboard bus ENBUS-2. Two
Separate backboard buses for processor cards
But both backboard buses are normal
Communication between the two processor cards
You.

[0014]

According to the present invention, the processor card of the own station is used.
When communicating with the other processor card,
Whether each of the integrated backboard buses can communicate
Diagnose. Diagnosis shows that all backboard buses are normal
The first and second processor cards
Set a different backboard bus for each. what
Only one of the backboard buses is diagnosed as normal.
The normal backboard bus to the first and second
Set for the processor card. This allows professionals
Sent on backboard bus for communication between Sessa cards
Prevents communication collisions that occur on one side of the backboard bus
If an error occurs and communication cannot be performed,
Redundant control that suppresses an increase in the communication load between
The device can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of a duplex control device to which the present invention is applied.

FIG. 2 is a diagram illustrating a data flow of the device of FIG.

FIG. 3 is a flowchart illustrating the operation of a backboard bus diagnostic unit.

FIG. 4 is a flowchart illustrating an operation of a backboard bus designation setting unit.

[Explanation of symbols]

 10 Processor Card 12 Backboard Bus Diagnosis Unit 14 Backboard Bus Designation Unit 16 Backboard Bus Switching Unit ENBUS Backboard Bus ENSEL Backboard Bus Register

Claims (4)

(57) [Claims] (1) A dual backboard bus interconnects with each other.
The battery that is used preferentially according to the mounting position
First and second processor cards to which a board bus is set.
And over de, to these first and second processor cards, either
A backboard bus register for setting information as to whether or not to select a backboard bus, and a backboard bus which is duplicated when a processor card of the own station communicates with a partner processor card. A backboard bus diagnostic unit for diagnosing whether or not communication is possible; and when the backboard bus diagnostic unit diagnoses both backboard buses as normal, the backboard bus register stores the first and second backboard bus registers in the backboard bus register. Set information to select different backboard bus for each processor card
When only one of the backboard buses is diagnosed to be normal, a backboard bus designation setting unit that sets information for selecting a normal backboard bus in the backboard bus register. And a duplication control device. 2. The system according to claim 1, wherein the first processor card and the second processor card each include a backboard bus switching unit for switching which of the dual backboard buses is used for transmission of the own station. Item 2. The dual control device according to Item 1. 3. The backboard bus switching unit according to claim 2, wherein one of the backboard buses is designated in accordance with a designation of a backboard bus designation setting unit of the own station.
The redundant control device according to the above. 4. The redundant control device according to claim 1, wherein said backboard bus diagnostic unit repeats the diagnosis at a constant cycle.