JPH0130166B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an operator's console for a distributed control system that performs process control, and particularly to a display method for a CRT display device that displays trend data.

<Conventional technology> For example, in batch control for receiving and shipping process fluids, etc., trend data representing the control status from the start to the end of batch control is continuously collected in accordance with the batch, and this data is used in a distributed control system. It has been conventional practice to display information on a CRT display device in a control station.

<Problems to be Solved by the Invention> However, since this data collection method is continuous, when the storage memory for collecting data becomes full, old data is discarded in order to store new data. It is not possible to memorize and save trend data that represents the status of batches, and even if this trend data is displayed on a display device such as a CRT in the control station, the batch data at any given time may not match the batch. The problem was that it was difficult to determine whether or not there was.

<Object of the Invention> The present invention solves the above problems, and enables trend data for batch control to be recorded and stored at the operator's station, and the data matches the batch. The purpose is to obtain a display method that makes it easy to judge whether the

<Method for Solving the Problem> The method of the present invention for solving this problem is to provide a control station with various control functions with a message sending function, and to display a trend graph using a batch trend function when connected to this control station. A message receiving function for receiving a message from the message transmitting function is provided in an operator's station, and a data storage means for storing currently executed control data, and a guide for storing data obtained by the same control performed in the past as guide data. a data storage means is provided, (a) collects control data currently being executed by a message from the message sending function and starts storing it in the data storage means; (b) a guide stored in the guide data storage means; (c) displaying a trend of the currently executing control data that has been controlled to be superimposed on the guide data; (d) displaying the currently executing control data by a message from the message sending function; This display method is characterized by terminating the collection of trends and terminating the trend display.

<Example> The display method of the present invention will be explained in detail using the block diagram shown in FIG.

FIG. 1 shows the functional blocks of a general control station and operator's station and their connections. 1 is a control station, 2
is the operator's station. Furthermore, the control station 1 has a sequence control function 11, a feedback control function 12, and a message transmission function 1.
3, the operator's station 2 includes a message receiving function 21, a data communication function 22, a batch trend function 23, a data memory 24, and a display device 25.

From this, the control station 1 has the sequence control function 11 or the feedback control function 1.
2 performs control operations, and the control data is sent to the data communication function 2 of the operator's station 2.
2 and processed by the batch trend function 23. Trend data from the batch trend function 23 is collected into the data memory 24 and also displayed on the display device 25.

At this time, as shown in FIG. 2A, the signal _s1 from the message transmitting function 13 of the control station 1 is received by the message receiving function 21 of the operator's station 2, and the message signal _s1 causes the operator's station 2 to A collection operation is started to store data D, which is a pair of trend data and time, in the data memory 24 (B represents the data D collection period), and at the same time, the trend data is displayed on the display device 25 according to the time. . Then, data D is stored and displayed in sequence, and data D is collected by a message signal _s2 from the next control station 1 or a signal t from a timer or the like started by message signal _s1 shown in b. Terminate it. In this way, the trend data can be displayed on the screen of the display device and simultaneously stored in the data memory 25 using the message signal.

In addition, the timing for transmitting this message signal can be set arbitrarily, so if you set it to the required time, you can collect trend data for the necessary time in batch control, and transfer this data to the CRT at each time. can be displayed. Further, although not shown, trend data for a certain period of time can be recorded on a recorder and this data can be saved.

For example, in batch control as shown in FIG. 3, except for the period T ₃ in which the control data represents a substantially constant value, there is a batch start period T ₁ in which the control data fluctuates.
By specifying only a certain period of time, ie, the batch end period _T2 , data can be recorded and saved for only that period.

In this way, as shown in Figure 4, the CRT
On the display screen, if the horizontal axis is time T, point A is the start point of trend data collection, and point B is the end point of trend data collection, the current data D is displayed on the screen with time, and the status of batch control is displayed. It can be read from a CRT in real time, and these trend data can be recorded and saved.

Furthermore, from FIG. 1, the data memory 24 includes a first data memory 241 and a second data memory 242.
As shown in FIG.
41 indicates the period T ₁ of batch control performed in the past.
Or ideal data D _{G (} D ₁₁
〜D _1n , D ₂₁ 〜D _2o ) is the time (t ₁₁ 〜 _{t 1n} , t ₂₁ 〜 _{t 2o} )
The second memory 242 stores data D _{P (D 31 to D 3n ,}
D ₄₁ to D _4o ) are set to time (t _{11 )} by the message signal from control station 1 as described above.
~t _1n , t ₂₁ ~t _2o ) are collected and stored.

The data thus stored is displayed on the screen of the display device according to the steps shown in the flowchart of FIG. In this flowchart, data display starts in step (1), data of the currently executed control is displayed in step (2), and presence or absence of past guide data _DG is determined in step (3). However, if there is past data, {Y} is
The data is displayed in (4), and if there is no past data in (3) {N}, (5) ends and the process returns to step (1) again.

That is, as shown in FIG. 6, past data is displayed as guide data _DG by the control circuit in the batch trend function 23, and the image is combined with the currently executed control data _DP and displayed on the display device 25. will be displayed.

In this way, past data is displayed on the screen of the display device 25 as control guide data D _G , and control is performed by superimposing the currently executed control data D _P on top of this guide data D _G. If executed, ideal control will be achieved.

<Effects of the Invention> As described above, according to the present invention, trend data can be stored and displayed by collecting trend data for a certain period of time using message signals from a control station. ,Also,
Since past batch data can be displayed on the display screen as control guide data and control can be executed by superimposing the current control data on top of it, efficient control can be performed.

[Brief explanation of drawings]

FIG. 1 is a block diagram for explaining the display method of the present invention, FIG. 3 is a diagram showing normal batch control, FIG. 4 is a diagram of a display screen showing the display of data collected by the present invention, and FIG. 5 is a diagram showing the data stored in the first memory and the second memory. FIG. 6 is a flowchart of the display on the display screen, and FIG. 7 is a diagram of the display screen when the display method of the present invention is used. 1... Control station, 11... Sequence control function, 12... Feedback control function, 1
3...Message sending function, 2...Operator's station, 21...Message receiving function, 2
2... Data communication function, 23... Batch trend function, 24... Data memory, 241... First memory, 242... Second memory, 25... Display device.

Claims (1)

[Scope of Claims] 1. A control station having various control functions is provided with a message sending function, and an operator's station connected to the control station and displaying a trend graph using a batch trend function receives a message from the message sending function. In addition to providing a receiving function, a data storage means for storing control data currently being executed and a guide data storage means for storing data obtained by the same control performed in the past as guide data, Collecting control data currently being executed by the message and starting storing it in the data storage means, (b) displaying the guide data stored in the guide data storage means, and (c) superimposing it on the guide data. Displaying a trend of the currently executed control data that has been controlled, and (d) terminating the collection of the currently executing control data and terminating the trend display in response to a message from the message sending function. Display method.