JPS5832424B2 - Dual hierarchy system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dual-system hierarchical system comprising a dual-system host computer and a plurality of low-order computers.

Conventionally, in a dual hierarchy system, as shown in Figure 1, upper computers IA and IB and lower computers 31 and 3
A switching device 2 is provided between □, .

Here, 7 is a signal detection end, and 13 is an operation end.

Therefore, in order to perform bumpless switching between the host computers IA and IB, a separate transmission line 4 that constantly exchanges information between the dual-system host computers IA and IB and a computer mutual diagnosis function are required. be.

Furthermore, since the essential device 2 exists between the upper computer 1 and the lower computer 3, the reliability of the dual-system upper computer 1 depends on the switching device 2, resulting in an unreliable system.

SUMMARY OF THE INVENTION An object of the present invention is to provide a dual hierarchical system having a simple and reliable switching mechanism by effectively utilizing transmission functions.

The present invention connects a higher-level computer and a lower-level computer with a transmission line,
When configuring a control device by transmitting data between computers, both dual-system host computers always receive the same signal.
The same calculations and processing are performed, but the signal transmission to the lower-level computer is
Dual system switching is easily realized by only performing one masked system.

An embodiment in which the dual hierarchical system according to the present invention is applied to process control will be described below.

Figure 2 shows the overall configuration of this system. Detection end 7□1.
・・・・・・7.7 ・・・・・・72、・・・・・・
・.

The process signals taken in from 121 7nl, 7 nm are sent to signal processing computers 81, 8□, 8
After signal processing such as correction and scale conversion is performed by n, and the signal is converted into a digital serial signal, it is sent to the host computer 10, host computer 11, etc. through the transmission line 9. Loop control computer 12, 122. ......, transmitted to 12n.

The loop control computer 12 performs minor closed loop control and operates the operating terminal 130. ,..., 13. l!
.

13.2. ,..., 13□,...
13nl...

13nm control.

When the host computers 1o and ii receive a target value for the loop control computer 12, for example, the board 11 receives a transmission signal, it performs a transmission/reception process according to the flow shown in FIG.

Since both the host computer 10 and the host computer 11 have the same address, when the received address matches their own address, both receive the following signal.

It is determined whether it is a transmission command or a reception command, and if it is a reception command, both computers receive the same signal.

If it is a transmission command, next it determines whether the own computer is in mask mode or backup mode, performs the transmission process only if it is in mask mode, and if it is in backup mode, it just ends reception, and then Prepare for reception.

With the above transmission method, if the host computers 10 and 11 have the same calculation and processing functions, they receive the same signals, so they can always perform the same calculations and processing and obtain the same output signals. .

Since switching between dual systems can be performed by transmitting or not transmitting this output signal, switching can always be performed smoothly and without bumps.

The situation at the time of switching is briefly explained as follows.

During the period T shown in Figure 3, for example, when system A is used, if a failure in system A is self-diagnosed, it is immediately switched to the healthy side as in the example in Figure 5, which will be described later. .

At this time, the higher-level computer that has experienced the error will, for example, stop outputting, so the lower-level computer will temporarily lack a signal, but this period is at most one cycle, and from the next cycle T2, the higher-level computer will return to normal. This does not pose a problem since the communication is with the computer.

Here, the upper computer selector 15 selects the upper computer 10.11.
An example of the selection logic is shown in FIG.

In other words, the condition that there is no failure according to the self-diagnosis results of the host computers to and ii and the AND condition of the selection button.
Selection is made by A1 or ANDB, ).

Here, FF is a flip-flop, and if a signal enters the set side S, it outputs 1 to Q, and if a signal enters R, it outputs 1 to Q.

Also, OR is an OR condition.

Incidentally, if it is determined that there is an abnormality in the self after being once selected, this is determined by the AND condition ANDA2 or ANDB2, and the other systems are mutually selected.

According to the present invention, since the host computer always receives the same signal, the host computer can execute two operations at the same time, and in the event of an abnormality, it is possible to switch only by the output mode of the switching selector. , a simple and highly reliable system can be realized.

The boiler master signal and water supply mask signal for boiler control are calculated and transmitted to the loop control computer 12 through the transmission line 9 to perform cascade control.

A transmission control device 14 is provided to control the transmission of signals such as the above process signals and target values.

Here, the method of signal transmission by the transmission control device 14 will be explained with reference to FIG. 3. This figure shows the transmission numbers from the transmission control device 14, computers 8□, 8□, ......, 8n, upper computer 1
0°11 or loop control computer 12. ．． 12□.

..., 12n) is shown, and the upper side of the horizontal line is the transmission number,
The lower side represents the received number.

The transmission control device 14 periodically transmits transmission commands to each computer in a predetermined order.

T1 cycle in the figure is a transmission command to computer I,
Among the addresses given to each computer in advance, the address of computer I is set in the reception address field, and a transmission command is attached, and the data is transmitted.

Each computer receives this signal, decodes the received address, and determines whether it matches its own address.

In this case, only computer I matches its own address and receives the signal.

It then decodes this signal to be a transmission command and enters the transmission system.

Since the other computers do not match their own addresses, they stop receiving and start the next reception system.

Computer I remembers which data it should send to which computer, and in this T1 cycle, computer I
If sending from a computer to a computer ■, set the address of the computer ■ as the receiving address, set the receive command and the address of the own computer as the sending address, and send it along with the data. Each computer that receives this signal Only ■ receives a signal that is lower than the receive command due to address matching,
The received signal is determined to be a reception command and data reception is performed.

Here, various formats of signals, methods of inputting synchronization signals, etc. can be adopted.

Now, in the above signal transmission method, the host computers io, i
The switching of i is realized as follows.

The same address is assigned to both the host computer 10 and the host computer 11.

Furthermore, a higher-level computer selector 15 shown in FIG. 2 is provided externally, and logical selection is made to set one of the higher-level computers 10, 11 to mask mode and the other to backup mode, and the result is given to the higher-level computers 10, 11.

Top computer 10 and top computer

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of a conventional dual system hierarchy system, and FIG. 2 is an overall configuration diagram of a dual system hierarchy system according to the present invention. FIG. 3 is a time chart of the transmission method in the present invention, FIG. 4 is a flow chart of the transmission method in the host computer,
FIG. 5 is an example of the logic block of the upper-level calculation selector. 7...Detection end, 8, 12...Lower computer, 9...Transmission line, 10.11...Double system upper computer, 13... ...Operation end, 14...
...Transmission control device.

Claims (1)

[Claims] 1. In a dual-system hierarchical system consisting of a dual-system upper computer and multiple lower-order computers, there is a transmission line that connects the upper-level computer and multiple lower-order computers, and a signal transmission between the computers via the transmission line. a transmission control device to control, and a higher-level computer that performs a logical operation to set one of the dual-system higher-level computers to mask mode and the other to backup mode, and instructs each mode to the higher-level computer; selector, each of the dual-system high-level computers always receives the same signal and performs the same operation, and only one of the high-level computers whose mask mode is selected by the high-level computer selector A dual hierarchy system characterized in that a calculation result is sent to the lower-level computer.