Chart

This function block is used to refer to a chart in a HMI, which can display trend lines defined by values given by the matrix.

The matrix with the values will be connected to the input MX. Every row in the matrix represents one of the trend lines. The chart can display six lines at most, so only the first six rows are read and more rows will be ignored.

The number of sampling points for every trend line does not depend on the size of the matrix. The user can decide, if the display of the trend lines depends on the scaling of the X-axes or is completely independent. If the input iScaleX IS NOT connected, the number of drawn line segments will be calculated by the difference of the maximum and minimum X value. If the input iScaleX IS connected, its value defines the number of line segments. This means there will be iScaleX+1 points used and interconnected to form the line.

The input iOff is used to set the offset, which defines the index of the starting point within a row to read the values. If more points than values in the remaining row are needed, the object starts reading again at the beginning of the row. If the offset is larger than the number of elements in a row, this offset is ignored and the values are read from the beginning.

The minimum and maximum values of both axes can be set by the inputs lMinX and lMaxX or lMinY and lMaxY.

The input bShow is used to show or hide the HMI object. The input bEnab is used to set the chart active or inactive (grayed out). The update of the display is controlled with bTrig. When the input changes from LOW to HIGH the chart will be updated.

HMI object

The HMI object displays the course of up to 6 signals. If the chart has to display more values, than the number of sampling points, only the minimum and maximum value per sampling point will be saved. In case of many values and a short chart object, two lines will be drawn for every signal, which will describe the envelope of the original input values.

 

Parameters

In the parameter dialog a Chart HMI object is assigned to the function block.

Using the context menu of the function block, the mask designer can be invoked as the parameter dialog. The mask designer is used to create the assignment to the HMI object. Now the preferences of the HMI object can be set with the help of the mask designer.

The parameter dialog of the object is used to select the language depending on the font for the scales. The display style of the scales, the minimum and maximum value and the number of tics can be set for both axes. Additionally, the colors for the different elements of the object can be selected. Here it is possible to decide if a grid is shown or not.

Signals

Name I/O Type(s) Function
MX I Data type independent Plain text
iOff I WORD Offset
iScaleX I WORD Number of line segments to be drawn
lMinX I LONG Minimum of the X scale
lMaxX I LONG Maximum of the X scale
lMaxY I LONG Maximum of the Y scale
lMinY I LONG Minimum of the Y scale
bShow I BIT Show/hide chart
bEnab I BIT Enable/disable chart
bTrig I BIT Update chart (change LOW-> HIGH)

Note: If inputs are not connected, the object appears with the corresponding default parameters that have been entered in the mask designer. Otherwise, the input signal from the function block overwrites the according setting from the parameter dialog.

Visualization

The colored highlight in the function block indicates, whether a HMI object is assigned or not.

Comments

The data type of the input MX will be defined by connecting a signal.

The inputs lMinX and lMaxX have to be connected both or not at all.

The inputs lMinY and lMaxY have to be connected both or not at all.

Example

Given is a 1x10 matrix with the values {(0,10,1,9,2,8,3,7,4,6)}. The offset is set to 0, so the chart line will be start drawing with the first element of the matrix.

If iXScale is set to 4, the line will consist of four segments, which means the first five points are used as sample points for the line.

If iXScale is set to 99, the line will consist of 99 segments, which means 100 points are used as sample points for the line, in that way the ten existing points are used again and again.