JPH0445843B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field to Which the Invention Pertains] The present invention is directed to appropriately adjusting operating conditions for controlled equipment controlled by a sequence controller (hereinafter also simply referred to as a PC) that sequentially executes a series of programs. The present invention relates to an operating condition monitoring and control device that monitors operating conditions and determines and displays the cause when the operating conditions are not satisfied.

[Prior art and its problems]

Conventionally, operating condition monitoring and control devices in this type of field have been designed for so-called failure diagnosis, by outputting or displaying all of the operating conditions that are thought to be the cause, and from which they can be selected based on human judgment. This method involves finding the cause of the problem in one's hometown and dealing with it. For this reason, the current situation is that the operator's experience and intuition must be relied upon to ultimately accurately determine the location of the abnormality.

In order to avoid this kind of work, a method as shown in FIG. 5 has been proposed. Incidentally, FIG. 5 is a block diagram showing a conventional example of a supervisory control device. In the figure, 20 is a sequence controller (PC), 21 is a memory, 22 is an arithmetic circuit, and 23 is a sequence controller (PC).
24 is an amplifier, 24 is an input/output circuit (I/O), 25 is a controlled device, 26 is a counter, 27 is a computer (CPU), and 28 and 29 are interface devices.

That is, in this method, the execution status of the program in the memory 21 executed by the arithmetic circuit 22 is monitored by the counter 26, and the overtime of the time cycle is used as a trigger to transmit the program executed at that time and its result to the interface device 28. , 29 to the CPU 27 and simulated by the CPU 27 to find the cause of the failure.

However, according to this method, the required time for each unit operation of the controlled device must be constantly compared with the standard time, calculated, and the results stored, resulting in an increase in the capacity of internal memory and counters. Furthermore, since it leads to an increase in the program calculation time, it is necessary to simultaneously provide a fault diagnosis function inside the PC that mainly has the operation control function, which has the disadvantage of significantly increasing the burden.

[Purpose of the invention]

This invention was made in view of these points,
First, it attempts to directly detect missing or abnormal operating conditions without relying on human judgment, and second, it attempts to minimize the increase in internal memory capacity even though it is inside the PC that controls the controlled equipment. It is an object of the present invention to provide an operating condition monitoring and control device that can be used to monitor operating conditions and minimize program calculation time.

[Key points of the invention]

This invention was made based on the fact that if the operating condition monitoring control program is constantly scanned inside a sequence control device, the processing time would be enormous. The supervisory control program is started only when at least one of the operating conditions does not hold, and the cause is investigated, thereby shortening the processing time and reducing the memory capacity.

[Embodiments of the invention]

FIG. 1 is a block diagram showing an embodiment of this invention.
FIG. 1A is a block diagram showing the inside of the block in FIG. 1 more specifically, FIG. 1B is a relay circuit diagram to help understand FIG. 1 or FIG. 1A, and FIG. 2 is a diagram showing the present invention. FIG. 2 is a block diagram showing an example of application to Plato. In Figure 1, 5 ₁
1 is an instruction switch, 5 ₂ is a display device, 6 is a state detection device, 11 is an operating condition determining means, 12 is a condition monitoring necessity determining means, 13 is a monitoring item determining means, 14 is a bit condition detecting means, and 15 is a monitoring item Output determination means 16 is display item output means.

That is, each means 11 to 16 shows the inside of the data processing device 1 of the sequence control device 4 configured as shown in FIG. be. In FIG. 2, 2 is an interface device with external equipment, 3 is an interface device with the data processing device 1, 5 is a man-machine interface device, 6 is a state detection device, and 7 is a controlled device. The sequence control device 4 performs well-known normal sequence control based on a predetermined program and various operating conditions given from the state detection device 6, and also performs the following monitoring operations.

The inside of each block in FIG. 1 can be more specifically shown, for example, as shown in FIG. 1A, but to help understand this figure better, reference is also made to a relay circuit diagram as shown in FIG. 1B.

Here, the operating conditions are, for example, conditions for safely operating the controlled equipment, and these operating conditions are given via the state detection device 6. For example, if we assume that each item of the operating conditions corresponds to contacts x ₁ , x ₂ , _... , contact x ₁ as shown in Figure 1B,
It can be seen that the operating conditions can be monitored by inserting relay R1 in series with the series circuit of x ₂ . . . x _o . In other words, if relay R1 operates, it means that all operating conditions are met, and if it does not operate, it means that at least one operating condition is not met (missing). is the operating condition determining means 11.
In addition, in Figure 1B, the contacts x ₁ , x _{2 ...} Therefore, in FIG. 1A, in order to unify these, they are arranged through an exclusive OR circuit EOR. Furthermore, the mask signal is used to remove condition items that do not need to be monitored among these contacts. In this way, the means 11 can detect whether each operating condition is met or not.

On the other hand, as shown in FIG. 1B, the contacts x ₁ and x ₂
...There is a contact S between the series circuit of x _o and relay R1.
is provided. This contact S is operated manually or automatically, and the detection result by the relay R1 becomes valid only when this contact is closed. Therefore, if this is manually operated, it can be left open so that no monitoring is performed. On the other hand, in the case of automatic operation, the contact S is usually selected from among the contacts x ₁ to x _o to be operated last in time or a similar contact, and monitoring is performed using this contact. The part where such instructions or selections are made corresponds to the condition necessity determination condition 12 in FIG. 1A. In FIG. 1A, the means 12 includes an instruction switch ₅₁ , which determines whether or not monitoring is necessary.

As shown in Figure 1B, contact S and relay R
A relay R2 is connected in series to a series circuit with the contact _r1 of the relay R1. This is to detect that there is a lack or abnormality in the operating condition by operating relay R2 when at least one of the operating conditions is not satisfied even though the contact S is operated. In FIG. 1A, the monitoring item determining means 13 corresponds to this part. The monitoring items mentioned here are:
The contacts x ₁ , x _{2 .} . . In other words, relay R2 performs control based on operating conditions x ₁ to x _o .
This corresponds to the monitoring items of a series of programs, and since there are usually multiple such programs,
By providing a relay similar to relay R2 for each program, it is possible to easily determine which monitoring item should be viewed.

The bit condition detecting means 14 in FIG. 1A is composed of, for example, an exclusive OR circuit EOR, and first
In order to ensure consistency with the monitoring items determined in step 1, certain items of the operating conditions given through the EOR of means 11 are masked. FIG. 3 is a reference for explaining an example of a monitoring item list, and M indicates whether the input contact for each operating condition is a make contact (“1”) or a break contact (“0”). The output of the means 14 is designated by N. Note that this is an example in which the first operating condition item is masked (“0”).

When an output (trigger signal) is issued from the means 13, a predetermined monitoring program is started, and based on this, the monitoring item output determination means 15 determines whether the means 13
and corresponding operating conditions, here contacts x ₁ , x ₂ ... x _o
The missing condition item is found by reading each state of and examining it. At this time, if the input state of the operating condition is logical "0" and normal, "0" is the correct answer, and therefore,
It is possible to immediately identify an abnormal location where the value is "1". In other words, there is no need for a separate memory for storing information on whether each operating condition is normal. Note that the logical product circuit AND of means 15 is
The above-described operations are performed based on the trigger output from the means 13, and thereby the missing operating condition items can be output (displayed) via the display item output means 16. In addition, means 12
It goes without saying that even if an output is being output from the means 13, if the trigger output is not output from the means 13, the monitoring program will not be activated and no output will be obtained.

Although the hardware configuration has been mainly described above, the above-described processing can also be performed using software.

FIG. 4 shows a flowchart in such a case, and as is clear from the figure, in this case, each means shown in FIG. 1 or FIG. 1A corresponds to each step of the program. This can be easily realized.

〔Effect of the invention〕

According to this invention, since monitoring is performed using a trigger as a condition, there is no need to constantly monitor operating conditions, so it is sufficiently practical even if it is implemented inside a sequence control device that mainly has an operation control function. Moreover, since operating conditions can be used not only for control but also for monitoring, it is possible to easily deal with changes in operating conditions. Furthermore, even if the sequence control device is equipped with such a function, the monitoring program is started only when an instruction for monitoring is given and the operating conditions are not met, so the program calculation time is shortened and the original This has the advantage that it can be applied without interfering with operational control.

On the other hand, since the operating conditions are shared with normal control, it is easier to create monitoring programs, which not only improves work efficiency when creating software, but also allows for easier handling of changes in operating conditions. This not only reduces debugging time at the time of plant delivery, but also improves the operability of debugging tools.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of this invention.
FIG. 1A is a block diagram showing the inside of the block in FIG. 1 more specifically, FIG. 1B is a relay circuit diagram to help understand FIG. 1 or FIG. 1A, and FIG. 2 is a diagram showing the present invention. FIG. 3 is a reference diagram for explaining an example of a monitoring item list, FIG. 4 is a flowchart showing a processing flow corresponding to FIG. 1, and FIG. The figure is a block diagram showing a conventional example of a supervisory control device. Code explanation, 1...Data processing unit (CPU),
2, 3...Interface device, 4...Sequence control device, 5...Man-machine interface device, 5 ₁ ...Instruction switch, 5 ₂ ...Display device, 6
...State detection device, 7...Controlled equipment, 11...
Operating condition determining means, 12... Condition monitoring necessity determining means, 13... Monitoring item determining means, 14... Bit condition detecting means, 15... Monitoring item output determining means,
16...Display item output means.

Claims (1)

[Claims] 1. Controlling a controlled device while executing a predetermined sequence program, and performing various operations for safely operating the controlled device when a pre-stored monitoring program is started. An operating condition monitoring and control device that reads and monitors conditions includes a detection means 11 that detects whether all of the operating conditions are met and outputs a condition failure signal when at least one of the conditions is not met; a selection means 12 for selecting whether to enable or disable the detection output from the detection means; and a selection means 12 which selects whether to enable or disable the detection output from the detection means, and a selection means 12 which outputs an instruction to enable the detection output from the selection means and when the condition failure signal is detected by the detection means. Trigger signal generation means 13 detects this and generates a trigger signal when the trigger signal is output from Judgment means 1 that takes in the condition item and judges the condition item for which the condition is not satisfied.
5. An operating condition monitoring and control device comprising: