Trend chart drawing method and device applied to industrial monitoring system

Abstract

The invention provides a trend chart drawing method and device applied to an industrial monitoring system. The drawing method includes the steps that the time span of the production process is divided into a plurality of continuous time units according to the width of a display area; all the data values in the production process are acquired and traversed, and the data values are affiliated to the corresponding time units according to time points corresponding to all the data values; the data values in each time unit are compared so that the maximum value and the minimum value of the data values in each time unit and the sequence of the time points corresponding to the maximum value and the minimum value are determined; the maximum values and the minimum values are drawn in a rectangular coordinate system of the display area to form trend points; the trend points in all the time units are connected with a curve according to the time sequence to form a trend chart. Through the drawing method, the whole variation trend of the production process can be completely displayed in the display area.

Description

technical field [0001] The invention relates to the field of industrial control, in particular to a method and device for drawing a trend graph applied in an industrial monitoring system. Background technique [0002] In the field of industrial control, the trend graph can visually show the change process of the analog quantity, and is an indispensable part of some industrial monitoring software. Normally, a trend graph is a two-dimensional coordinate graph with time as the X axis and trend points as the Y axis. And in order to show the change trend of the data value more clearly, in the trend graph, use smooth lines to connect these trend points to form a trend line, which makes it easier for relevant personnel to study the production process, so as to implement effective monitoring of the production process. [0003] When drawing a trend chart, the most important thing is how to determine the trend point. At present, there are mainly two methods for determining the trend...

AI Technical Summary

Problems solved by technology

[0004] Among them, the method of using all the collected data points as the trend points of the trend line has the advantage that no data processing is required and the operation is simple. When the data is large-capacity data, the display area cannot display all the data, resulting in an incomplete trend line drawn and unable to show the overall change trend presented by all data points

[0005] When the sampling results are used as the trend points of the trend line, since the selected trend points have certain randomness, the trend represented by the trend line formed by these trend points also has certain randomness, which may lead to the trend shape represented by the trend line There is a large discrepancy between the actual trend of the production process, so that the trend shape indicated by the trend line does not match the actual trend, which may lead to misjudgment of the trend of the production process by technicians

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