JPH02757B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an alarm output method in a plant monitoring device.

Generally, a plant monitoring device is equipped with an input device, a calculator, a display device, etc., reads a large number of plant state quantities from each part of the plant into the computer through the input device, sequentially compares each state quantity with an alarm limit value, If the limit value is exceeded, a warning message is created and the warning message is output to the display device.

By the way, when outputting such an alarm message to a display device, in the conventional method, all state quantities that deviate from limit values are output as alarms without considering the processing ability of the operator. was.

For this reason, a large number of alarm messages are output on the display device, including those with high and low alarm levels, and the operator must distinguish between those that are important and those that are not, and then take appropriate measures. However, the disadvantage is that the process requires a lot of time and effort. Furthermore, this result
There was a delay in responding to important warnings, and there was a risk of a serious accident.

The present invention takes into account the processing capacity of the operator and causes the display device to output the amount of alarm messages that the operator can process in order of the plant state quantities that deviate from the limit value, starting from the highest alarm level.
It is an object of the present invention to provide an alarm output method in a plant monitoring device that allows an operator to respond to changes in the state of the plant and operate the plant safely.

Hereinafter, the present invention will be explained with reference to the drawings.

FIG. 1 shows a flowchart of processing of an alarm output method according to an embodiment of the present invention.

Each state quantity of each part of the plant is taken into the comparison section 2 via the input reading section 1.

That is, as shown in FIG. 2, a large number of analog type detectors 3 and contact type detectors 4 are arranged at measurement points in each part of the plant, and analog signals Ai', ON- The OFF signal Bi' is converted by the analog input device 11 and contact type input device 12 of the input reading unit 1 into analog detection information Ai of the corresponding digital value and digital value Bi of "1" and "0", respectively. Thereafter, the data are sequentially input to the comparison unit 2 at each scanning period.

The comparator 2 stores each alarm limit value Ci corresponding to the input analog detection information from each measurement point and a plurality of second limit values associated therewith.
Note that the second limit values are values set at equal intervals within a range that deviates from the alarm limit value.

Therefore, the analog detection information Ai input to the comparator 2 every scanning period is first compared with the alarm limit value Ci.

As a result, if the following conditional expression Ai>Ci...(1) does not hold, the analog detection information
It is checked whether Ai deviated from the previous warning limit value Ci, and if it does not deviate, it is ignored, but if it deviates, it is stored as ``changed'' to return to normal.

On the other hand, if the above conditional expression (1) is satisfied, the degree of deviation of the analog detection information Ai from the alarm limit value Ci is further checked using the following conditional expression (2).

Ai>Ci+m×SCV (m=1~n)...(2) (However, SCV is a constant value determined corresponding to each alarm limit value Ci for setting each second limit value, m is an alarm Here, the analog detection information Ai is set with an alarm limit value Ci as the limit of the normal value, but the analog detection information
Just because Ai deviates from this alarm limit value Ci does not mean that an immediate danger will occur in the plant.
This is because the alarm limit value Ci is set on the normal value side with a considerable margin. There is an absolute limit value as a value that deviates from the alarm limit value Ci and causes danger to the plant. Therefore, for each analog detection information Ai, n alarm levels are set between the alarm limit value Ci and the absolute limit value in the area where the respective analog detection information Ai deviates from the alarm limit value Ci. As a result, each analog detection information Ai can be normalized, and all analog detection information Ai of different dimensions can be expressed on the same coordinate axis with time on the horizontal axis and alarm level on the vertical axis. Become. ) In the process of checking conditional expression (2) from m=1 to n, if the conditional expression does not hold, the checking of the conditional expression is stopped, and the alarm level m at that time is stored.

Next, the alarm level m obtained this time is compared with the previous alarm level of this analog detection information Ai, and if it is different from the previous alarm level, it is judged as "changed".
is stored as.

FIG. 3 shows a specific example of the above-mentioned analog detection information Ai, alarm limit value Ci, second limit value, and alarm level m. The left vertical axis of the figure is the limit value,
The right vertical axis shows the alarm level, the horizontal axis shows the scanning time, and each second limit value is set at intervals of SCV in a range exceeding the alarm upper limit value Ci. Now, assuming that the analog detection value A'i output from the analog detector 3 exceeds the alarm limit value Ci and changes as shown in the figure, at each scanning time t1 to t4, the analog detection value A'i is input to the comparator 2 at each scanning time _t1 to _t4 . Since all of the analog detection information Ai ₁ to _{Ai 4} are values that have changed across the upper limit Ci or each second limit value at the time of the previous scan, they are all stored as “changed”.

In this way, the change state of each analog detection information Ai input to the comparator 2 is determined for each scanning period, and those that are "changed" are stored.

On the other hand, if each contact detection information Bi input from the contact type input device 12 of the input reading unit 1 to the comparator 2 differs from the previous state, the measurement point is also marked as "changed".
is stored as.

In this way, when the comparator 2 stores "change" for each measurement point, based on this,
The calculation unit 5 in FIG. 1 calculates the total sum N of "changes". Furthermore, the total sum N is the scanning cycle time
The number n of changes per unit time is calculated by dividing by Tj. In this case, the scanning cycle time Tj will be constant if the scanning process is executed by hardware, but since it is usually executed by software using a program,
It differs each time due to the influence of interrupt processing, etc. Therefore, the calculation unit 5 subtracts the previous scanning time from the current scanning time to calculate the scanning cycle time.
Tj is determined, and the number of changes n=N/Tj is calculated.

In this way, when the number of changes n is determined by the calculation unit 5, the next alarm output suppression level (Suppress
Pointer (hereinafter abbreviated as SP) setting unit 6 sets the SP value as shown in the block diagram of FIG. 4 based on the number of changes n.

That is, first, in block 61, the _SP1 value at that time is calculated from the number of changes n using the function SP=f(n) as shown in FIG. For example, when the number of changes n is 0 to 10, the SP ₁ value is 0, when it is 11 to 20, the SP ₁ value is 1, when it is 21 to 35, the SP ₁ value is 2, and so on. This SP value is equal to the alarm level in Figure 3.
Corresponds to 1. Here, the reason why the number of changes n is counted not only when the analog detection information Ai goes in the deviation direction but also when it goes in the normal value direction is because, for example, when the analog detection information Ai moves in the deviation direction as a response operation in case of a plant abnormality. This is because it is necessary to cancel the operation performed when the analog detection information Ai is heading towards the normal value.

This function SP=f(n) is calculated by taking into account the characteristics of the plant, that is, the tendency of change in the alarm output amount that is predicted to occur when the plant goes into an abnormal state.
It is ergonomically determined based on the processing capacity of the operator, that is, the amount of alarm output that the operator can appropriately process. Therefore, as will become clear from the following description, the higher the processing ability of the operator, the gentler the slope of the illustrated function curve.

By the way, as mentioned above, the comparison section 2 stores the contact detection information "changed" based on the digital value Bi input from the input reading section 1, but this contact detection information includes: It also includes some important contact detection information that greatly affects plant operation. Further, when this contact point detection information changes, the states of many measurement points in each part of the plant naturally change accordingly. In the case of this embodiment, such important contact detection information is specified in advance, and the
The SP value is also set in advance.

Therefore, at this time, in block 62, it is determined whether or not there has been a change in the specified contact detection information, and if there has been a change, the change in the specified contact detection information has been made.
The SP _binary value α is retrieved in block 63.

Next, in block 64, the previously obtained SP value SP ₁ and its SP ₂ are compared, and if SP ₂ > SP ₁ , the process goes through block 65 and then in block 67, the SP ₂ is changed to SP.
Set as value.

On the other hand, if there is no change in the designated contact detection information, or even if SP ₂ < SP ₁ , block 66
It is determined whether SP setting prohibition timer TMR1 is operating or not. If it is operating, setting is prohibited, but if a certain period of time has elapsed since the previous setting, block 6
7, that SP ₁ is set as the SP value. after that,
In block 68, β seconds is set in the SP setting prohibition timer TMR1, and the SP setting operation in the SP setting section 6 is completed.

In this way, the SP setting unit 6 extracts SP ₁ based on the number of changes n calculated by the calculation unit 5, and if there is a change in the designated contact detection information at that time, the corresponding SP ₂ is extracted, and the larger is set as the new SP value. Also, at this time
In order to prevent frequent updates, the SP setting operation is performed every predetermined period of time by the SP setting prohibition timer TMR1. Note that this timer TMR1 is configured so that the timer operation is performed by subtracting 1 from the value β set there every second.

In the output determination section 7 in FIG. 1, as described above,
The alarm level m of each analog detection information Ai stored in the comparing section 2 is the SP set in the SP setting section 6.
The values are sequentially compared, and it is determined that m>SP...(3).

Based on this determination result, the output unit 8 creates an alarm message consisting of the name of the plant measurement point that satisfies the above conditional expression (3), current value, limit value, alarm level, etc. A warning is output to a display device such as a window. Therefore, the warning amounts within the operator's processing capacity are always output to the display device in descending order of warning level.

On the other hand, at this time, regarding the contact detection information stored in the comparator 2, if the SP value reaches a predetermined value according to the SP value at this time, a warning is output for all of the contact detection information.

Thereafter, when the scanning time reaches a predetermined period of time after passing through the delay section 9, the above-described series of alarm output processing is performed again.

For example, the outputs A' ₁ to A' 4 of analog detectors ₃ placed at four measurement points in a plant are
Assume that the changes occur as shown in the figure. Then, at each scanning time t ₁ to _{t 5} , the analog detection information A ₁ to A ₄ input from the input reading section 1 to the comparator 2
Among them, those marked with a circle are stored in the comparator 2 as "changed".

Based on this stored information, the calculation unit 5 calculates the number of changes per unit time n, and the SP setting unit 6 further calculates the number n of changes per unit time.
SP value is set.

That is, in the example of FIG. 6, the SP value was set to 1 at scanning time t ₁ and the number of changes n = 2, but at scanning time t ₂ the number of changes n = 3, so the SP value is set to 1.
The value changes from 1 to 2. Furthermore, at scanning time t ₃ ,
Since the number of changes n decreases to 2 again, the SP value also decreases from 2 to 1. Thereafter, in the same manner, scanning time t ₄
Then SP ₁ = 1, at t ₅ SP = 2, at t ₆ SP = 1...
As a result, the SP curve shown in FIG. 7 is obtained.

Based on this SP value, the output determination unit 7 determines whether or not to output an alarm for each of the analog detection information A ₁ to A ₄ for each scan. is output as a warning.

In other words, since the SP value directly corresponds to the alarm level, if this is superimposed on Figure 6,
The SP value can be represented by a chain line, and when the analog detection information exceeds this value, that is, at the scanning time _t1 , analog detection information _A2 to _A4 is output as an alarm. Similarly,
Even at scanning time _t2, alarms are output for analog detection information _A2 to _A4 , and _A1 is not output. However, this analog detection information A ₁ comes to be output at time t ₃ when the SP value decreases.

In other words, this means that, for example, when the plant condition becomes unstable and there are fluctuations in the status of a large number of measurement points, the alarm output can be limited to the number that the operator can handle, and the fluctuations will subside. This means that information on measurement points with low alarm levels that had been suppressed until then will also be gradually output as an alarm.

This allows operators to properly handle any abnormality that occurs in the plant, and allows the plant to operate safely.

For the same reason, analog detection information A ₁ to A ₄ at scanning time t ₄ , A ₃ and A ₄ at t ₅ , and A ₂ to A ₄ at t 6.
A ₄ ... and so on, the alarms are output in sequence.

Now, when an operator monitors the plant status,
The display device shows the measurement point name, current value, limit value,
It is necessary to display alarm levels, etc.

Therefore, when the output determination unit 7 determines a measurement point at which an alarm is to be output, an alarm message required by the operator for that measurement point is created and displayed on a CRT, typewriter, or the like.

Note that several functions f(n) for determining the SP value from the number of changes n in the above embodiment may be prepared in advance, and the operator may select one of them as appropriate from the outside. Or also set
An operator may be able to adjust the SP value by ±1 from the outside.

As described above, according to the present invention, an amount of alarm is always output that is commensurate with the processing capacity of the operator, and the alarm output is performed in descending order of alarm level, so that the operator can avoid information overload. This makes it possible to respond to the alarm information in a short time.
It will be possible to prevent accidents and operate the plant safely.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the processing flow of the alarm output method of the present invention, Fig. 2 is an explanatory diagram of the input reading section, and Fig. 3 shows the scanning time and the change in analog detection value at one plant measurement point. Explanatory diagram showing the relationship between limit values and alarm levels, Part 4
The figure is a block diagram showing the processing of the SP setting section in Figure 1, Figure 5 is an explanatory diagram for calculating the SP value, and Figure 6 is a waveform diagram for explaining a specific example of the alarm output method of the present invention. , Figure 7 shows the situation at that time.
It is an SP curve diagram. DESCRIPTION OF SYMBOLS 1...Input reading part, 2...Comparing part, 3...Analog type detector, 4...Contact type detector, 5...Calculating part, 6...
SP setting section, 7... Output determination section, 8... Output section, 9...
Delay section, 11...analog type input device, 12...contact type input device, 61-68...block.

Claims (1)

[Scope of Claims] 1. Analog detection information or contact detection information at measurement points in each part of the plant is read in sequence at each scanning cycle, the read analog detection information is compared with an alarm limit value, and analog detection that deviates from the alarm limit value is performed. In an alarm output method for outputting an alarm to a display device with information necessary for monitoring information measurement points, a plurality of alarms normalizes each of the analog detection information to a region that deviates from each of the alarm limit values of each of the analog detection information. The level is set, and the measurement point that deviated from the normal range to the alarm limit value and entered the alarm state, and the change in the above analog detection information above and below each set alarm level between the previous scan and the current scan. The number of measurement points that changed per unit time is calculated by counting the number of measurement points that changed per unit time, and the number of measurement points that changed from among the plurality of alarm levels is determined based on a predetermined relationship. The higher the alarm level increases, the higher the alarm level is selected and set as the alarm output suppression level. Among the analog detection information, the information necessary for monitoring only the measurement points exceeding the alarm output suppression level is collected for each scan. An alarm output method characterized in that an alarm is output to the above-mentioned display device. 2 Sequentially read the analog detection information or contact detection information at the measurement points of each part of the plant in each scanning cycle, compare the read analog detection information with the alarm limit value, and check the measurement points of the analog detection information that deviated from the alarm limit value. In an alarm output method for outputting an alarm of information necessary for monitoring to a display device, a plurality of alarm levels are set for normalizing each of the analog detection information in an area where each of the analog detection information deviates from each of the alarm limit values, Measurement points that deviated from the normal range to the alarm limit value and entered the alarm state, and measurements when the above analog detection information changed above or below each set alarm level between the previous scan and the current scan. The number of measurement points that changed per unit time is calculated by counting the number of measurement points that changed per unit time, and as the number of measurement points that changed from among the plurality of alarm levels increases based on a predetermined relationship. While selecting a high first alarm level, when predetermined contact detection information among the contact detection information at each measurement point changes, the predetermined one of the plurality of alarm levels is selected in response to the change. compare the first alarm level and the second alarm level, set the larger one as the alarm output suppression level, and select the alarm output suppression level from the analog detection information. An alarm output method characterized by outputting an alarm to the display device for each scan with information necessary for monitoring only for measurement points exceeding the above range. 3. The alarm output method according to claim 1 or 2, characterized in that the setting operation of the alarm output suppression level is performed at fixed time intervals different from the scanning period.