JPS59157759A - Dual system - Google Patents

Abstract

PURPOSE:To improve the reliability of a system by providing a bus line through which data is transmitted in serial in parallel with a aystem bus. CONSTITUTION:A microprocessor 41 gives control information to a control circuit 48 through a local bus 42 and system bus interfaces 441 and 442. Control information from the control circuit 48 is outputted to a prescribed process device through a process interface 50. If a trouble occurs on a bus 46, a switching selecting circuit 49 switches the circuit from the control circuit 48 to a control circuit 47. A serial interface 43 and serial bus 45 are connected through the control circuit 47. Thus, the control function is held and continued.

Description

[Detailed Description of the Invention] [Technical Field to Which the Invention Pertains] This invention aims to improve reliability by duplicating a common bus to which a control device (controller) having a built-in processor such as a microprocessor is connected. Regarding the redundant system.

[Prior art and its problems]

In general, a control device with a built-in processor has the advantage that its processing method can be changed by a program, that is, the functions and performance of the control device can be developed and improved without changing the hardware. It is widely used in devices with simple functions to devices with relatively complex and important functions. However, in such a case, if a failure occurs in a central processing unit such as a processor, the functionality of the entire system will be lost. It is desirable that the

FIG. 1 is a block diagram showing the basic configuration of a control system, FIG. 2 is a block diagram showing a control system equipped with a bank-up device, and FIG. 3 is a block diagram showing a system in which main parts are duplicated.

That is, a generally well-known control system includes a processor 1, a memory 2, a system bus 3, and a controller 4 (41) as shown in FIG.
~4n) etc.

In such a system, the following method can be used to protect against the above-mentioned software failures.

is possible. One method is to provide backup devices 151...15n, as shown in FIG.

In this case, the bank up devices 151...15n include
At least, it has a function to monitor the state of the process and change the amount of operation so that the process can be changed to a complete and appropriate state, manually or automatically, if necessary. In addition, 11,
12.13 and 14 (141-14n) are the same processor, memory, system bus and I10 controller as in FIG. 151 for such backup equipment.
By providing 15n to 15n, even if a failure occurs in any of the devices 11 to 14 and the function of the device is lost, the minimum necessary control function can be guaranteed.

On the other hand, there is also a method as shown in FIG.

In the figure, 21M and 21S are processors, 22M,
22S is memory, 23 is system bus, 24 (241~
24n) is an I10 controller, and 25 is a bus switch. That is, two sets of common parts such as processors and memories are provided and one is masked (21M).

22M), the other one is slave (21S, 22S),
When multiple functions on the mask side stop due to a failure, etc., the bus switch 25 automatically or manually switches to the slave side, thereby preventing the entire system from stopping. be. Note that 241 to 24n are individual interface sections corresponding to process equipment, and even if a failure were to occur in these sections, the impact would be limited to a certain area, so such individual interface sections should not be used. As with common parts such as processors and memories, whether or not to duplicate them is determined as appropriate depending on the application.

In this example as well, the controllers 241 to 24n of the pull-up device 1I10 shown in FIG. 2 can be provided.

Finally, in any of the above systems, the common section and the individual sections are connected to each other by a common system bus, and information is exchanged via the system bus. And this system node is usually an address bus,
This information is sent in parallel from the data bus, control information bus, etc.9.

A so-called word-serious bus is used for receiving.

-i: In addition, the components connected to this bus are often mounted on multiple printed boards, but in such a case, if a failure occurs in a component mounted on one of the printed boards, If the common cross line is latched up to the 0'' or l# state, there is a drawback that normal information exchange is impossible.For this reason, it is difficult to duplicate various devices or functional elements as described above. This is possible, but since the system bus is composed of a large number of signal wires, it has the disadvantage that it is difficult to realize due to constraints such as the number of terminals on the printed circuit board, or the significant cost increase associated with duplication. .

[Purpose of the invention]

The present invention was made under the above circumstances, and an object of the present invention is to provide a means for simply and easily realizing duplication of a control system.

[Summary of the Invention] A system in which a common control unit such as a processor, memory, etc. and individual units such as input/output devices controlled by the common control device are arranged in parallel via a word-serial bus, is capable of transmitting information in one piece.
A bit-serial bus that serially transmits bits is provided.
The common control section 9 and individual sections are arranged in parallel on the bus via respective predetermined interface sections.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 is a block diagram showing an embodiment of the present invention. In the figure, 41 is a processor and memory displayed together, 42 is a local bus, and 441 is a local bus.
, 44zi) system bus interface, 46 is a system (WordShi!J 7.h) hash, 48 is a control circuit, 50 is a process ink face section L 43
11432 is a serial bus interface, 45 is a serial (bit serial) bus, and 47 is a control circuit.

The processor and memory 41 are connected via an interface 441 to a word serial bus 46 capable of parallel transmission of information in word units, and an ink face 442
The control circuit 48. For a general control system configured by connecting process interfaces 50, a bit serial bus 45 capable of serially transmitting bit-by-bit information is provided, and the processor, memory 41, and control circuit 47 are connected to each other via a serial bus. It is connected to the bus 45 through interfaces 431 and 432 to make the system redundant. therefore,
The serial interfaces 431 and 432 have at least a function of converting data on the bus 45, which is exchanged bit-serial, into word units. Note that the switching selection circuit 49, like the bus switching device 25 in FIG.
Either control circuit 47 or 48 is selected.

The operation shown in FIG. 4 will be explained.

The microprocessor 41 performs predetermined control based on the program stored in the memory, and connects the local bus 42 and system bus interface 441 as necessary.
+442 to provide control information to the control circuit 48. At this time, if the switching selection circuit 49 is configured to make use of the signal on the control circuit 48 side during normal operation and disconnect the signal on the control circuit 47 side, the control information from the control circuit 48 can be transferred to the process interface. The signal is output to a predetermined process device via the face 50. Note that the status information etc. taken in from the process equipment is routed through the opposite route to the above, that is, the process ink face 50, the switching selection circuit 49,
The signal is applied to the processor and memory 41 via the control circuit 48, system bus interface 442, system bus 46, system bus interface 441, and local node 42, and the system operates normally using such operations as basic operations. Here, bus 46. If a failure occurs in either the interface 441 or 442 or the control circuit 48, one of the signal lines making up the bus 46 becomes latch-up, causing the common control section (4A) and the individual section (4B) to If it becomes impossible to exchange information between them, the control function for the individual section (4B) will not only stop, but also the functions of all other devices or devices may stop. Therefore, when such a situation occurs, the processor 41 switches the control logic (software or program), stops information communication via the system bus 46 that was used during normal times, and restarts the serial ink face 431, Serial bus 45, serial interface 432, control circuit 47, switching selection circuit 4
9 and the process interface 50 to continue and maintain the control function. The switching selection circuit 49 is configured such that the switching is performed from the control circuits 4 and 7 to the control circuit 48, for example, after the processor 41 tests the function of the individual section (4B) at the time of system startup and confirms that the individual section (4B) is normal. Let's set it. Also, the individual part (4B) is 1 here.
Although only one unit is shown, usually multiple units are installed,
Control by the common unit (4A) is also normally executed in a time-division manner. Therefore, since the common part (4A) must exchange information with a large number of individual parts (4B), the bus configuration is a word-serial bus that can transmit multiple bits of information at once, and this is the main bus. (main or ′
It is of course possible to use a system consisting of a serial bus and its interface section as main or regular use, and to provide a system consisting of a word serious bus as a backup.

The embodiment shown in FIG. 4 is an example in which a word serial bus and a bit serial bus are duplicated at the time of system startup in a basic control system, but it is also possible to do the following.

FIG. 5 is a block diagram showing another embodiment of the invention. As is clear from the figure, in this example, the bus is added not only to the system bus but also to the common section 4A' for duplication. Here, common part 4A is used regularly, common part 4A
' is used as a backup, and the system status or the memory contents of the common unit 4A on the regular side are transmitted via the serial bus 45 on the spare common unit 4A' side to the regular side without going through the bus 46. Since the control function of the common section 4A can be traced without any damage, even if the regular side fails, it can be instantly switched to the standby side, creating a non-stop system. It is possible to realize this. It goes without saying that the individual section 4B may also be duplicated in the same manner as described above. Note that since other points are the same as those in FIG. 4, detailed explanation will be omitted.

FIG. 6 is a block diagram showing still another embodiment of the present invention. By further promoting duplication of the above-mentioned individual parts 4B, each of the individual parts 4B and 4B' is divided into three parts (4B1 to 4B3.4B1' to 4B3'). When the card is switched to the 4B2 side, the failed card 4Bl is transferred to the spare side 4B1'
This allows the card to be restored to a normal state based on the card. In each of the embodiments shown in FIGS. 4 to 6, a comparison circuit is provided in the switching selection circuit 49, and
If the control results from the common section are always outputted via both buses 45 and 46, the circuit 49 assumes that the data is correct and outputs a predetermined value only when the outputs of both the control circuits 47 and 48 match. Since it can be applied to process equipment, it has the advantage of reducing the risk of erroneous output and improving reliability.

Note that this point can be similarly applied to each input from the process equipment.

〔Effect of the invention〕

According to this invention, control is always performed using a word serial bus with high-speed response, and even if the response is slightly lower than that of a word serial bus in the event of a failure, the bit serial bus has good noise resistance and is easy to isolate. By using a bus, it is possible to realize a fault-tolerant system that is economically superior. In general, bit serial buses are superior to word serial buses in terms of noise resistance, are easy to insulate, and are inexpensive. It has a unique advantage over simply duplicating the word serial bus.It also has the advantage of being relatively simple, such as duplicating the bus and then duplicating only the common parts. This makes it possible to easily upgrade the system to a fully duplex system that duplicates the components without changing the architecture.

Furthermore, when the common parts are duplicated, the contents of the memory can be constantly traced using the standby bus, making it possible to realize an uninterrupted system and improving reliability. be.

Note that the present invention can be applied not only to the above-mentioned process equipment but also to general input/output equipment.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the basic configuration of the control system, Fig. 2 is a block diagram showing a control system equipped with a puncture amplifier device, Fig. 3 is a block diagram showing an example of a system in which main parts are duplicated, and Fig. 4 5 is a block diagram showing an embodiment of the invention, FIG. 5 is a block diagram showing another embodiment of the invention, and FIG. 6 is a block diagram showing still another embodiment of the invention. Code explanation 11.21M, 218...processor, 12, 22
M. 22S...Memory, 3, 13, 23.46...System bus, 41-4n, 141-14n, 241-2
4n... Engineering 10 controller, 151~15n...
Bank up device, 25...Bus switch, 41...
Processor and memory, 42...Local bus, 4
311432...Serial bus interface, 44
1+ 442...System bus interface, 45
... Serial bus, 47°48 ... Control circuit, 49
...Switching selection circuit, 50...Process interface circuit Figure 1
Arodesu Figure 3

Claims (1)

[Scope of Claims] l) A controller comprising a memory that stores at least a program on a common bus that transmits information in parallel, and a processor that executes a predetermined control operation based on the program stored in the memory; Each one controlled by that controller! In a control system in which input and output units are installed in parallel via predetermined interfaces, another common bus for serially transmitting information is provided in parallel with the common bus, and the information transmitted in series is transmitted in parallel with the common bus. A redundant system characterized in that the controller and various input/output crab units are installed on the other common bus via an interface unit for transmitting data in a format that can be received by the controller and various input/output crab units. . 2. In the duplex system according to claim 1, at least one of the controller or the various kinds of crab knits is duplexed, and one is used to produce paddy. A redundant system characterized by operating one for one day and one for use as a standby.