JPS59611A - Graphic displaying method of process quantity - Google Patents

Abstract

PURPOSE:To hold the significance of a graph before and after display ranges are changed corresponding to a process quantity and to follow up even a process quantity which varies abruptly by changing the kinds of graph line simultaneously with the display range change, and displaying the upper and lower limits of a new display range digitally. CONSTITUTION:An upper limit A, lower limit B, and permissible minimum display value C are set initially and a measured value X is read. Whether the value X is less than the value C and greater than the value C is checked and when X>C, it is unnecessary to change display ranges, so the operation quantity XD= X-B/A-B.R of a display for displaying the process quantity X is calculated. When X>=A, the value A is changed into B+(A-B)*2 and the value C is changed into B+(C-B)*2 respectively. The line kinds of graph are changed and specified after settings are changed, and the upper limit value A and lower limit value B are displayed digitally; and newly set values A and B are used to calculate the operation quantity XD, which is displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a process quantity graph display method I that automatically switches the display range according to the size of the process quantity.

[Technical background of the invention and its problems]

The process quantities of a plant or the like are often displayed graphically on the graphic display device 11.In this case, if the process quantity changes significantly, it will go out of the display range, so it will be necessary to switch the display range for display.

FIG. 1 shows a general configuration of a graphic display device that displays by switching display ranges.

In FIG. 1I, the process amount of the plant 11 is measured by the measuring device 1-2, an appropriate measurement gain is selected by the range switching amplifier 13, and the process amount is sent to the display 161 via the process input device 14 and the arithmetic device 15. Nigelaf is displayed. 17 is a storage device.

Using the configuration shown in FIG. 1, it is possible to appropriately select the measurement gain of the amplifier 13 depending on the magnitude of the process amount and to automatically switch the range.

However, if only the simple 62 measurement gain is switched, the display before the switching point becomes meaningless and must be erased, resulting in a problem that the history of the process amount is lost.

However, it is possible to store the data in the storage device 12 and reproduce it, but in this case there is a problem that the storage device becomes large.

[Purpose of the invention]

When the display range is switched, the present invention simultaneously changes the line type of the graph and displays the display range digitally on the graph surface, thereby making it possible to switch ranges without losing the significance of the graphs before and after the range switch. This provides a method of graphically displaying process quantities.

[Summary of the invention]

The present invention switches the display range when the process graph displayed deviates from a predetermined range corresponding to the current display range, changes the line type of the graph, and furthermore changes the upper limit and L of the display range after switching. This is a method of displaying a process quantity graph by digitally displaying the upper limit and the lower limit on the graph, and thereby changing the display range while maintaining the significance of the graph.

[Embodiments of the invention] An embodiment of the present invention is shown in the flowchart of FIG.

FIG. 3 is an example of a graph displayed using display method 1 of FIG. 2.

Figure 2 shows the display range (upper limit) for each measurement period.

A case is shown in which the white lower limit value B of the lower limit value B) is constant.

In FIG. 2, first, in step (1), the above-mentioned A, B and the minimum display value C are initialized, and in step (2), the measured value X is read.

Next, in step (3), it is checked whether the measured value X is smaller than the upper limit value A.

If X≧A, it is necessary to increase the display range, so proceed to step (5).

X (If A, next 1 step (4) c Check whether the binary measured value X is larger than the minimum display value C.

If X≦C, it is necessary to lower the display range, so proceed to step (7).

If it is X)C, there is no need to change the display range, so proceed to step aυ(-) and calculate the operating amount XD of the display to display the process ilX using the following equation (1).

Here, R is the amount of operation of the display corresponding to the full scale (A-B).

If X≧A, 6 steps (5) 1 as described above
':.

Proceed and now change the upper limit At-B+(A-B)*21''-C2, allowable minimum display value CfB+(C-B) change 21'' and set each to the new values of A and C. do.

Also, if X≦C, I step (7) as described above.
l: Proceed, where A is B+(A-B)/2c, C is B
+(C-B)/2, and change this to the new A
and set as the value of C.

After changing the settings for A and C in step (6) or (8) above, change the graph line type (graph color, solid line, dotted line, broken line, etc.) in step (9). After specifying 62, the upper limit value A and the lower limit value B are displayed as digital values on the display in step Ql, and then in step Ql) the robot advances 1 m and calculates the above equation (1) using the newly set A and B. , the calculated XD is displayed on the display as the amount of movement.

When the XD display ends in step a3, the process returns to step (2), reads the measured value X again, and repeats the same operation.

The initial value of the allowable minimum display value C is, for example, the following (
2) It can be set using the formula.

c: B + (A-B)/3 ... Between songs (2
) Figure 3 is an example of a display using the display method shown in Figure 2.
At time t0, the display starts as a solid line graph in the display range of (A = 10, 8 = 0), and at time t1, x1 becomes ≥ person (A = 20.8 = 0), and the two display ranges are changed. At the same time, the graph becomes a broken line X, and furthermore, at time t, lag≦C, and the graph again becomes a solid line X in the range of (A=10.8=O).

In Fig. 3, two types of line types, solid lines and broken lines, are used, but other types such as dotted lines and chain lines can also be used, and it is also possible to display the lines in a variety of colors. Even a pen recorder is good enough for a graphic display.

In addition, the display range (A) at the time of display range switching and before and after switching
, B), it is possible to maintain the continuity of the six graphs as shown in FIG.

FIG. 5 is a flowchart showing another embodiment of the invention, in which the rate of change of the measured value X is taken into account.

In other words, let the difference from the previous measurement value X be ΔX=X−X,
The display range is switched when A, B, X, and ΔX satisfy predetermined conditions.

L is the display range width, and D is the value for determining the change device, but the calculation method is the same as in the case of Fig. 2, so
A detailed explanation thereof will be omitted.

〔Effect of the invention〕

As explained above, according to the present invention, in the process quantity graph display method 62 which switches the display range according to the size of the process quantity, the line type of the graph is changed at the same time as the display range is switched. By using a relatively simple method of digitally displaying the upper and lower limits of the new display range, the significance of the graphs before and after switching the display range can be maintained continuously, without increasing the burden on the storage device. Even process quantities that change rapidly, such as those that have oscillation, can be reliably tracked on an appropriate scale.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing the general configuration of a graphic display device to which the present invention is applied, FIG. 2 is a flowchart showing an embodiment of the method for graphically displaying process amounts according to the present invention, and FIGS. Each figure shows an example of a graph displayed by the method of the present invention, and FIG. 5 is a flowchart showing another embodiment of the present invention. 11 Plant 12 Measuring device 13 Range switching amplifier 14 Process input device 15 Arithmetic device 16 Display 17 Storage device (8733) Agent Patent attorney Yoshiaki Inomata (
(and 1 other person) Figure 1 Figure 3 A-to A-2θ A=10 β=OB=OE-θ Figure 4 β=/θ B=θ B=-A;t) Figure 5

Claims (1)

[Claims] When the process amount displayed in the graph deviates from the current display range 1: the corresponding predetermined range, the display range is switched and at the same time the line type of 1 Nigelaf is changed, and the upper and lower limits of the display range after switching are displayed as a graph. A method for displaying graphs of process quantities, characterized by displaying them digitally on a surface.