JPH059797B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a CRT display device that has been improved to make trend graphs easier to view. <Prior art> Conventionally, when displaying a trend graph on a CRT display device, as shown in FIG. 1, data V corresponding to the change in time T in the horizontal direction is sequentially plotted. A trend graph is displayed depending on the data. <Problems to be Solved by the Invention> For this reason, when the data value V fluctuates greatly over time T, the plot points of the data value V are far apart and the plot points are continuous, as shown in Figure 2. One drawback was that it was difficult to recognize as a trend graph. In addition, although data V is sampled in minimum time units, if the time interval for actually plotting data V on the CRT display screen is longer than the sampling time, analog Another drawback was that if small fluctuations HN in the data displayed on the trend graph TG due to high frequency noise etc. occur during the plotting time, this data fluctuation cannot be reliably displayed. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned drawbacks, and to provide a CRT display device that is easy to recognize and can reliably display even minute fluctuations. <Means for Solving the Problems> The present invention solves the above problems in the following two ways. (1) Input trend data in synchronization with a clock signal and use the plot times (T ₁ to T _o ) based on the clock signal and the data (V ₁ to V _o ) corresponding to each of these plot times as trend information. The starting point is the point (T ₁ , V ₁ ) and the point (T ₁ , (V ₁₊
Connect the two points V ₂ )/2) and find the midpoint m (1<m<
n) is the point (T _n , V _n ), the point (T _n , (V _n +
V _n-1 )/2), the maximum and minimum values of the three points (T _n , (V _n +V _n+1 /2)) are connected, and the ending point is the point (T _o , V _o ) and the point (T _o , (V _o +V _o-1 )/2)
A CRT display device comprising trend information display means for displaying bar graphs or dots on a display screen by connecting two points. (2) Sequentially sample the trend data in synchronization with the clock signal for one plot time (T _n −
processing means for obtaining the maximum value (V _n-nax ), minimum value (V _n-nio ), and average value (V _na ) of a plurality of trend data sampled within T _n-1 ) as trend information; a trend information storage means for storing information in a queue structure;
In accordance with the trend information in the trend information storage means, the maximum value (V _n-nax ), average value (V _na ), and minimum value (V _n-nio ) are determined in correspondence with the plot time (T _n ). A CRT display device comprising trend information display means for displaying a wide range of data by tying the lines together. Or, in (2), the trend information display means corresponds to the plot time (T _n ),
A wide data range is displayed by connecting the maximum value (V _n-nax ) and the minimum value (V _n-nio ), and the average value (V _na ) is displayed within this data range.
may be displayed with high brightness or in a color different from that of the data range. <Function> The CRT display device of the present invention functions as follows. (1) Set the starting point to the point (T ₁ , V ₁ ) and the point (T ₁ , (V ₁ +
Connect the two points V ₂ )/2) and find the midpoint m (1<m<
n) is the point (T _n , V _n ), the point (T _n , (V _n +
V _n-1 )/2), the maximum and minimum values of the three points (T _n , (V _n +V _n+1 /2)) are connected, and the ending point is the point (T _o , V _o ) and the point (T _o , (V _o +V _o-1 )/2)
Connect the two points and display a bar graph or dot on the display screen. (2) Connect the maximum value (V _n-nax ) and minimum value (V _n-nio ) in correspondence with the plot time (T _n ), and display a wide data range as a bar graph or dot. Further, the average value (V _na ) may be displayed within this data range with high brightness or in a color different from that of the data range. <Example> Hereinafter, an example of a CRT display device of the present invention will be described with reference to the drawings. FIG. 4 is a block diagram showing one embodiment of the present invention. The oscillator 1 outputs a clock signal CP of a predetermined frequency, and the processing circuit 2 outputs the clock signal CP from the oscillator 1.
In synchronization with the CP, trended data TV is input and subjected to predetermined processing, and then transmitted to the trend file update circuit 3. The trend file update circuit 3 queues the data from the processing circuit 2 to the trend file 4 having a queue structure in synchronization with the clock signal CP from the oscillator 1, and when the queue overflows, deletes data sequentially starting from the oldest data. To go. Then, the trend data files TF1 to TFn filed in the trend file 4 are sent to the trend display circuit 5.
displays trends on the VRT6 display screen using bar graph memory. The processing circuit 2 is designed to allow external designation of various processing modes, which will be described later, and the trend data files TF1 to TFn also have a corresponding queue structure. First, a case will be described in which a mode for determining the correspondence between time data (T) and data size (V) is designated as the first processing mode in the processing circuit 2. At this time, trend file 4 contains the following table 1.
Time data T ₁ to _{T o} and corresponding data values V ₁ to _{V o} are stored.

[Table] Here, time data T ₁ to _{T o} are clock signals
This represents the time it takes to display sampled trend data in synchronization with the CP as a plot (bar graph display or dot display) on the CRT display screen. Note that the data sampling timing may be set to the time data T ₁ to _{T o} as it is. The trend display circuit 5 then displays the trend data files TF1 to TF1 stored as shown in Table 1 above.
Read TFn and display the trend graph as shown below. The starting points are points (T ₁ , V ₁ ) and (T ₁ , (V ₁ +
It is displayed as a bar graph connecting the two points of V ₂ )/2). Next, the intermediate point m (1<m<n) is the point (T _n ,
V _n ), point (T _n , (V _n + V _n-1 )/2), point (T _n ,
(V _n +V _n+1 )/2) A bar graph connecting the maximum and minimum values of the three points is sequentially displayed. The last end point is the point (T _o ,V _o ) and the point (T _o , (V _o
+V _o-1 )/2) Displayed as a bar graph connecting the two points. By displaying each plot point as a bar graph in this manner, a bar graph display trend graph 10 as shown in FIG. 5, for example, is displayed on the screen of the CRT 6. As a result, even if the data V is accompanied by rapid fluctuations, the data at each plot point is displayed as a bar graph, so the trend graph 10 is recognized as a continuous line. In the above description, all plot points are displayed as bar graphs, but it is also possible to display them as a mixed plot of bar graphs and dots. That is, the starting point is the point (T ₁ , V ₁ ) and the point (T ₂ ,
The _intermediate point m is displayed as a bar graph connecting points (T _n , V _n ) and (T _n , V n+1 ), and the end point is displayed as a bar graph connecting points (T n , V n ) and (T _n , V _n+1 ). , V _o ) may be displayed as a dot. In addition, the starting point is displayed as a dot at the point (T ₁ , V ₁ ), the intermediate point m is displayed as a bar graph connecting the point (T _n , V _n-1 ) and the point (T _n , V _n ), The end points are points (T _o , V _o1 ) and (T _o ,
It may also be displayed as a bar graph connecting V _o ). Next, in the processing circuit 2, as the second processing mode,
A case will be explained in which a mode representing the fluctuation of time data (T) and data (V) between plot times is specified. In _this case, as shown in _FIG. The data PD is sequentially extracted at _the timing _{expressed by ( timing} expressed _by The data is stored as corresponding data in the trend file 4 via the trend file update circuit 3. Therefore, the contents of the trend file 4 at this time are as shown in Table 2 below.

[Table] Then, the maximum and minimum values are connected by a bar graph corresponding to each plot time. As a result, as shown in FIG. 7, a trend graph 20 consisting of a bar graph connecting the minimum value V _n-nio and maximum value V _n-nax of the data is displayed on the CRT 6 corresponding to each plot time _T n. Is displayed. In addition, when displaying the average value V _na corresponding to time T _n at each plot time, first, as shown in FIG. In addition to displaying in a bar graph form, this data range 31 includes high brightness,
Alternatively, the average value (V _na ) 32 is displayed in a color different from that of the data range 31, thereby displaying the trend graph 30. Incidentally, each calculation of the trend file data described above can also be realized by a computer program. <Effects of the Invention> As described above, according to the present invention, by displaying a continuous trend graph, data transitions in the trend graph can be easily recognized, and the trend graph can be displayed in a form that includes even minute fluctuations in data. can. In addition, by displaying a bar graph with a line connecting the maximum and minimum values within each plot time, the graph will not become difficult to read due to the plot points being scattered, and it will also be possible to display the average data value for the plot time interval. Since the weight of the data range represented by the maximum value and minimum value is also displayed, it becomes easy to recognize the data situation and it becomes possible to display an accurate trend graph.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an example of a conventional trend display, Fig. 2 is a diagram showing how plot points are dispersed in the conventional method, Fig. 3 is a diagram showing an example of displaying analog trend data, and Fig. 4 is a diagram showing an example of the present invention. A block configuration diagram showing one embodiment of the device, FIG. 5 is a diagram for explaining a display example of a trend graph in the first processing mode of the device of the present invention, and FIGS. FIG. 7 is a diagram for explaining a display example of a trend graph in a second processing mode of the apparatus. 1... Oscillator, 2... Processing circuit, 3... Trend file update circuit, 4... Trend file,
5...Trend display circuit, 6...CRT, 10,
20, 30...Trend graph.

Claims (1)

[Claims] 1. Trend data is input in synchronization with a clock signal, and plot times (T ₁ to _{T o} ) based on the clock signal and data (V ₁ to _{V o} ) corresponding to each of the plot times are input. processing means for obtaining trend information as trend information, trend information storage means for storing the trend information in a queue structure, and starting points are set at point (T ₁ , V ₁ ) and point (T ₁ , (V ₁ + V ₂ )/2), and the midpoint m (1<m<n) is the point (T _n , V _n ),
Point (T _n , (V _n +V _n-1 )/2), Point (T _n , (V _n +
Connect the maximum and minimum values of the three points of V _n+1 )/2), and the end points are the points (T _o , V _o ) and (T _o , (V _o +
A CRT display device comprising trend information display means for displaying bar graphs or dots on a display screen by connecting the two points V _o-1 )/2). 2 The trend data is sampled sequentially in synchronization with the clock signal for one plot time (T _n -
processing means for obtaining the maximum value (V _n-nax ), minimum value (V _n-nio ), and average value (V _na ) of a plurality of trend data sampled within T _n-1 ) as trend information; Trend information storage means stores information in a queue structure, and the maximum value (V _{n -nax} ) and average value (V _na ) and minimum value (V _n-nio )
and a trend information display means for displaying a wide range of data by connecting the CRT display device. 3. The trend information display means displays the maximum value (V _n-nax ) in correspondence with the plot time (T _n ).
and the minimum value (V _n-nio ) to display a wide data range, and within this data range, the average value (V _na ) is displayed with high brightness or in a color different from that of the data range. A CRT display device according to claim 2, characterized in that: