JPS6114526B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a device for manipulating and displaying process variables in a distributed control device.

(Background of the Invention) In a distributed control device, comparatively small-scale control units are distributed in various areas of a controlled object, and each area of the controlled object is divided and controlled. In such a control device, the distributed control units are connected to each other by data communication lines, so that the entire control object can be comprehensively controlled. The control unit has appropriate input/output devices depending on the nature of its task. Examples of input/output devices include analog input/output devices, digital input/output devices, operator input/output devices, and various display devices. Since the distributed control device is a risk-distributed system, it has high reliability, safety, and maintainability, and also has good cost performance because the system configuration can be easily expanded or reduced according to the scale of the controlled object.

FIG. 1 shows the conceptual configuration of a distributed control device.
In FIG. 1, 11, 12, ......, 1n are control units (hereinafter referred to as field control stations), 2 is a monitoring and operation unit for operators (hereinafter referred to as operator's station),
3 is a data communication line, and 4 and 4' are terminators.
Each station has intelligence (such as a microcomputer) and processes its own tasks at its own timing. Each station also exchanges information on a time-sharing basis via the data communication line 3. Of these, the operator's station 2 collects various data from each field control station 11-1n and displays it to the operator, and also transmits data to each field control station 11-1n according to the operator's instructions. Operator's Station 2 is equipped with a CRT graphic display to facilitate man-machine communication.

Field control station 1i
(i:1~n) and operator's station 2
An example is shown in FIG. In FIG. 2, a field control station 1i includes a microcomputer and various input/output devices, and sends and receives signals to and from a process 5 to be controlled through an instrumentation wiring 6. The operator's station 2 is connected to the field control station 1i by a data communication line wired under the floor. Operator's station 2 is color CRT21
and keyboards 22 and 23, through which the operator monitors and operates the process. The format of the screen drawn on the color CRT 21 is designed to be convenient for quick and accurate man-machine communication. One such screen is one that displays a simulated indicator of an analog controller. The indicator displayed on this screen actually moves the pointer to indicate the measured value, so it is convenient for intuitively understanding the status of the controlled object.

An example of a screen drawn on the CRT 21 is shown in FIG. These screens display the status of each point of the controlled object by simulating an analog indicator, each scale band being one indicator, and measured values are shown in bar graphs. The status of eight locations is displayed on one screen. These eight indicators indicate measurements that are related to each other. The symbol below each indicator is the tag number. Among the eight indicators, the indicators with tag numbers F401, L402, and L410 are composite indicators that simulate the indicators of analog controllers, and indicate the input signal (process measurement value) PV with a bar graph. The triangular pointer on the right side (set value pointer) indicates the set value SV, and the triangular pointer on the left side (output pointer) indicates the adjustment output signal.
Shows MV. The numbers on the scale band are the input signal PV
This is the value used to read the set value SV. When reading the value of the output signal MV, this scale band is regarded as a 0 to 100% scale, and the position of the output pointer relative to it is read in %. Other indicators are simply measurement value indicators and indicate the measured value (PV) with a bar graph. The fact that the bar graph does not appear indicates that the measured value is zero or the lowest scale value. The indicated value of the indicator is also displayed numerically. The numbers and their engineering units are displayed in the space above each indicator. The display order is from top to bottom: engineering unit, input signal PV, set value SV, output signal MV.
(%). These allow the values of each signal to be known precisely.

The value of the output signal MV is controlled by the field control.
Although it changes automatically according to calculations performed by the station 1i, it can also be changed manually by the operator using the keyboard. Switching between automatic mode and manual mode and operation of output signal MV and set value SV can be performed for each individual controller by means of a keyboard 22 provided below the CRT screen and paired with an indicator. The key 221 switches between automatic mode and manual mode each time it is pressed. When the key 222 is pressed, the operation value increases continuously, and when the key 222' is pressed, the operation value decreases continuously. In the automatic mode, the set value pointer is a conspicuous color (for example, red) and the output pointer is a subdued color (for example, green).
Alternatively, if 222' is pressed, the set value SV changes and the set value pointer moves. When the set value SV changes, the output MV changes and the output pointer moves as the field control station 1i calculates accordingly. When switching to manual mode, the color of the setpoint pointer and the output pointer alternate, with the setpoint pointer becoming a subdued color and the output pointer becoming a more prominent color. If the key 222 or 222' is pressed in this state, the output MV changes and the output pointer moves. When in other states such as cascade control, backup mode, input open, calibration in progress, host computer setting mode, etc., both the set value pointer and output pointer turn to a subdued color, and keys 222 and 222' are used to control the operation. It has become impossible to do so. For each indicator, upper and lower limit values are defined for the input signal (measured value) PV and output signal MV as necessary. As shown in FIG. 4, the upper and lower limit ranges are represented by straight lines A and B parallel to the scale band. A is the upper and lower limit range of the input signal PV, and B is the upper and lower limit range of the output signal MV.

Such a screen is composed of three screens. The three screens are a background section screen, a constant section screen, and a variable section screen. The background screen is similar to that shown in FIG. 5 and shows constant information such as instrument scales, tag numbers, engineering units, etc. The constant part screen is as shown in FIG. 6, and shows the upper and lower limit ranges of the input signal PV and output signal MV. Since the upper and lower limit ranges may be changed by the operator as necessary, they are separated from the background and displayed as one screen. The variable section screen is the 7th
The diagram shows the input signal PV, set value SV, and output signal MV. These values change depending on process conditions and operator actions. Information on these three screens is provided to the CRT display device by respective predetermined programs.

The logical configuration in that case is shown in FIG. In other words, the information on the background screen is stored in the operator's station and in the tag list TGL.
This is displayed on the CRT using the background display program BGP.
given to the display device DIS. Since the background does not change while the same screen is displayed, background information is displayed only once on the CRT display device.
given to DIS. Since the CRT display device DIS has memory, given information can be displayed repeatedly. Since the background portion does not include data within the field control station 1i, the contents of the tag list TGL do not need to be communicated with the field control station 1i. The information on the constant part screen is held in the process parameter buffer PAB, and is given to the CRT display device DIS by the process constant display program PAP. The process parameter buffer PAB is controlled by the process constant communication program PACP.
Constants are taken from station 1i. Since the constant remains constant unless changed by the operator through the operator's station 2, it is also applied to the CRT display device DIS only once per screen. The information on the variable section screen is held in a process variable buffer PVB, and is given to the CRT display device DIS by the process variable display program PVP. Process variable
Batsuhua PVB has a process variable communication program
The data is taken from the field control station 1i periodically (for example, every second) by PVCP. Since variables change according to process conditions and operator actions, the process variable display program is also started periodically (for example, every second) to display the contents of the process variable buffer PVB.
Give to CRT display device DIS. As a result, the CRT 21 screen displays the current status of the process every moment.

(Problem to be solved by the invention) In such a device, an operator presses the key 22.
When the set value SV or the output signal MV is manipulated by 2 or 222', these values are given to the field control station by data communication, but this communication gives operator's station 2 control over the data communication. This is done each time the signal is rotated, so even if the operator continuously changes the manipulated variable on the transmission buffer, only discrete values are given to the field control station 1i. Therefore, when such a manipulated variable is brought from the field control station 1i and displayed on the CRT 21, the manipulated variable does not change smoothly. Although the amount of operation must change continuously and smoothly in accordance with the operator's expectations, if it remains as it is, it will change at irregular tempos depending on the timing of communication, which is extremely inconvenient for operation.

If all that is required is to smoothly change the manipulated variable displayed on the CRT 21 to the value intended by the operator, the contents of the transmission buffer may be displayed on the CRT 21. However, this alone does not guarantee that the operation amount displayed on the CRT 21 as intended by the operator will be reliably transmitted to the other station, so some kind of ingenuity is required.

(Objective of the Invention) The object of the present invention is to be able to continuously and smoothly change the amount of operation on a CRT without being affected by the timing of communication, and to
The purpose of the present invention is to provide a process variable operation/display device that can reliably transmit the operation amount as confirmed on a CRT to the other station.

In the present invention, input signals (measured values such as temperature, pressure, flow rate, etc. from the process) PV, set values (target values) SV, and output signals (output signals to valves, etc.) MV are collectively referred to as process variables. called,
Further, a process variable changed by an operation key is called an operation amount.

(Means for Solving the Problems) The present invention that achieves the above object includes a graphic display, operation keys, and an analog display of the operation amount on the graphic display, which can be given by the operator through the operation keys. Manipulation and display of process variables in an operator's station of a distributed control device having a microcomputer that supplies communication data to a partner station each time the communication initiative is handed over based on a communication request while changing it according to commands. a data collection means for periodically importing process variables from a partner station into the first buffer;
an increase/decrease initializing means which is activated when the operation of the operation key is started and which takes the variable to be operated from the first buffer into the second buffer and sets an increase/decrease mode; While continuing, it is activated periodically at a cycle sufficiently shorter than the operation cycle of the data collection means, and while the operation key is being operated, the value in the second buffer is displayed as the operation amount on the display. It changes in small steps so that it changes smoothly, and also sends a communication request to the other station that takes control of the communication, and also takes control of the communication after the operation key operation is completed. and an increase/decrease means for issuing a communication request conditional on receiving a message from the other station indicating that data has been written to the memory; operation amount display means for selecting the value in the second buffer during the increase/decrease mode and selecting the value in the first buffer when the increase/decrease mode is cancelled, and displaying the selected value on the graphic display; and means for returning the value in the second buffer to the first buffer and canceling the increase/decrease mode upon receiving a message from the other station indicating that data has been written to the memory.

(Example) The present invention will be described below. FIG. 9 is a logical configuration diagram of an apparatus according to an embodiment of the present invention. In Figure 9,
PVCP and PVB are the process variable communication program and process variable buffer, respectively as in the case of Figure 8, INP is the increase/decrease initial program, LNP is the increase/decrease end program, IDB is the increase/decrease buffer, IDP is the increase/decrease program, and SCVP is the send/decrease program. program, RCVP is a receive program, DIS is a display device, and MDP is a mark display program. Increase/decrease initial program
INP and increase/decrease program IDP are activated when key 222 or 222' is pressed. The initial increase/decrease program INP retrieves the data to be manipulated, that is, the set value SV or output signal MV, from the process variable buffer PVB and executes the increase/decrease buffer.
IDB, and the operation mode of operator's station 2 is shifted to increase/decrease mode. That is, the switch to the mark display program MDP is switched to the b side. The increase/decrease program IDP changes the value in the increase/decrease buffer IDB by a predetermined change △, and displays this value on the display device.
Give to DIS. Increase/decrease program IDP is key 222
Alternatively, while 222' is pressed, it is activated repeatedly every 50 ms, so the contents of the increase/decrease buffer IDB are changed by △ every 50 ms, and this is displayed one by one on the display device DIS. For this reason
To the operator, the set value SV pointer or the output signal MV pointer on the CRT 21 appears to move continuously at a constant speed. Increase/decrease program IDP
Also, the send program every time it works
Issue a communication request to SCVP. The increase/decrease program IDP is activated repeatedly every 50 ms as long as the increase/decrease mode continues even after key 222 or 222' is released. However, at this time, the value of the increase/decrease buffer IDB is not changed, and only a communication request is made. A flowchart of the increase/decrease program IDP is shown in FIG. Step 1 is the entrance to this program, Step 2 is the key 222 or 222' status determination section, Step 3
is the increase/decrease buffer IDB content change section, step 4 is the increase/decrease buffer IDB content display section, step 5 is the communication request section to the send program SCVP, step 6 is the timer start section, step 7 is the end processing section, and step 8 is the This is a communication request unit when no key operations are performed. The communication request at step 5 requires communication in send mode, and the communication request at step 8 requests communication in send+receive mode. Send mode is a communication mode in which you take the initiative in communication and do not receive (need) a response from the other party, and send + receive mode is in which you take the initiative in communication. This is a mode of communication in which the condition is that the other party communicates with the other party and receives a message from the other party indicating that the data has been written into memory.

As is clear from Fig. 10, during key operation,
When a send mode communication request is issued every 50ms and disappears during key operation (when key operation is completed)
, a send/receive mode communication request will be issued.

Returning to FIG. 9, when a communication request is issued, the send program SCVP sends the contents of the increase/decrease buffer IDB to the field control station 1i each time the communication initiative is handed over.
Therefore, generation of a communication request and actual communication are asynchronous. When the receive program RCVP receives an increase/decrease data writing end message from the field control station 1i in the send+receive mode (when key operations are completed), it notifies the increase/decrease end program LNP that the final communication has been received. Increase/decrease end program LNP
Based on this notification, the final value of the data in the increase/decrease buffer IDB will be updated to the process variable buffer.
Write to PVB and cancel increase/decrease mode. By canceling the increase/decrease mode, the switch to the mark display program MDP is switched to the a side.
Thereafter, the last written value is sent to the process variable buffer PVB from the field control station 1i. When the increase/decrease mode is canceled, the repeated activation of the increase/decrease program IDP is canceled.

When changing the manipulated variable using such a device, when the key 222 or 222' is pressed, the manipulated variable is transferred to the increase/decrease buffer IDB and updated at a predetermined speed, and this value is sent to the display device DIS at the same cycle as the update. given to. Therefore, on the CRT 21, the amount of operation changes continuously at a constant speed while the key is being pressed. Therefore, the operation amount changes smoothly in accordance with the operator's expectations, resulting in good operability.

In the increase/decrease mode in which the operation key 222 or 222' is pressed, process variables other than the operation amount changed by the operation key (this process variable is periodically imported from the partner station to the process variable buffer PVB). ) is
For example, the process variable display program PVP, which is started every second, can
It is displayed on the DIS superimposed on the manipulated variable that is increasing or decreasing, making it possible to simultaneously recognize changes in other process variables based on the manipulated variable.

Meanwhile, field control station 1
For i, the contents of the increase/decrease buffer IDB are sent by the send program SCVP asynchronously to the timing of increase/decrease, each time the communication initiative is handed over, based on a communication request. This situation can be seen in Chapter 11.
As shown in the figure. In other words, the display data uniformly changes by △ every 50 ms, but the communication data increases or decreases at that point every time the communication initiative is handed over.
Since the data in the IDB is sent out, it does not necessarily change uniformly. When the key is released, the communication data may not yet catch up with the final value in the increase/decrease buffer IDB. However, in the device of the present invention, the increase/decrease mode is not canceled even when the key is released, so the activation of the increase/decrease program IDP continues to be repeated. Since the key is released at this time, the operation of the increase/decrease program IDP branches to step 8 in FIG.
That is, it issues a communication request conditional on receiving a message indicating that data has been written into memory. Therefore, the next time communication is taken over, the final value in the increase/decrease buffer IDB is sent to the field control station 1i, and the field control station 1i writes this data into memory and sends/receives it. - When the data writing is completed according to the communication request in the mode, the field control station returns a message to the operator's station 2 to that effect. When the operator's station 2 receives this message, it releases the increase/decrease mode using the receive program RCVP and the increase/decrease end program LNP, and stops the activation of the increase/decrease program IDP. This ensures that the final value of the manipulated variable is supplied to the field control station 1i.

That is, the amount of operation intended by the operator and confirmed on the display device is reliably supplied to the field control station 1i. Of course, there are times when the displayed value and the actual value do not match during the change in the manipulated variable, but it is important that the final value match, and a temporary mismatch between the values in the middle is not a problem.

At this time, according to the increase/decrease end program LNP,
The final value of the data in the increase/decrease buffer IDB has been written to the process variable buffer PVB, and the switch to the mark display program MDP has been switched to the a side, so the manipulated variable written from the increase/decrease buffer IDB is displayed on a graphic display device. Since it is certain that this manipulated variable has already been supplied to the field control station 1i, the manipulated variable on the display matches the actual manipulated variable.

(Effects of the Invention) As described above, according to the device of the present invention, when monitoring and operating process variables by displaying them on the graphic display device of the operator's station in a distributed control device, it is possible to The amount of operation is not affected by communication operations and changes smoothly in accordance with the operator's expectations, and the amount of operation that the operator intended and confirmed on the graphic display device is reliably transmitted to the other station. I can do it.

[Brief explanation of the drawing]

Figure 1 is a conceptual configuration diagram of a distributed control device, Figure 2
The figure shows an external view of the field control station and operator's station, Figure 3 shows an example of the graphic display screen and operation keys, Figure 4 shows a portion of Figure 3, Figure 5, 6 and 7 are partial screens constituting the screen in FIG. 3, FIG. 8 is a logical configuration diagram of the software that displays the screen in FIG. 3, and FIG. 9 is a diagram of the apparatus according to the embodiment of the present invention. FIG. 10 is a flowchart of a part of the program shown in FIG. 9, and FIG. 11 is an explanatory diagram of the operation of the apparatus according to the embodiment of the present invention. 11-1n...Field control station, 2...Operator's station,
3...Communication line, PV...Input signal, SV...Set value, MV...Output signal, 22...Increase/decrease operation key,
BGP...Background display program, PVP...Process variable display program, DIS...CRT display device, TGL...Tag list, PAB...Process parameter buffer, PVB...Process variable buffer, PACP...Process Constant communication program, PVCP...Process variable communication program, INP...Increase/decrease initial program,
IDB...Increase/decrease buffer, IDP...Increase/decrease program, SCVP...Send program, RCVP...
Receive, program.

Claims (1)

[Claims] 1 Display the operating amount in analog on the graphic display, operation keys, and graphic display, and change this in accordance with commands given by the operator through the operation keys, each time the control of communication is handed over based on a communication request. A device for operating and displaying process variables in an operator's station of a distributed control device having a microcomputer that supplies communication data to a destination station, the device periodically importing process variables from the destination station into a first buffer. a data collection means; an increase/decrease initializing means which is started when the operation key starts to be operated and takes the variable to be operated from the first buffer into the second buffer and sets an increase/decrease mode; And while the increase/decrease mode continues, the data collecting means is activated periodically at a sufficiently shorter cycle than the operation cycle of the data collecting means, and while the operation key is being operated, the value in the second barrier is displayed as the operation amount on the display. When the change occurs, the change is made in such small steps that it changes continuously and smoothly, and the other station is issued a communication request that takes control of the communication and does not receive a response from the other station. After the operation is completed, an increase/decrease means for issuing a communication request on the condition that the station takes the initiative in communication and receives a message from the other station indicating that data has been written to the memory; Means for transmitting the value in the second buffer to the opponent station when the initiative is acquired, the value in the second buffer is selected during the increase/decrease mode, and the value in the first buffer is selected when the increase/decrease mode is cancelled. an operation amount display means that selects and displays on a graphic display, and upon receiving a message from the other station indicating that data has been written to memory, returns the value in the second buffer to the first buffer and increases or decreases the value. A device for manipulating and displaying process variables at an operator's station of a distributed control device, comprising means for deactivating the mode.