Modifying Analog Pen Properties

The properties of analog pens that you can change are those shown in the following images.  The right-click menu includes all properties that can be switched on or off.  The properties dialog includes these plus the properties that are set with a value such as pen width.

 A detailed description of each property follows the images.  (Be careful with Min and Max, Minimum and Maximum.  In one case the words relate to the scale range and in the other, to the legend view.  The descriptions will clarify the difference.)

To modify the properties of a pen plotting analog data:

1.   In the HDV’s pen legend, select the analog pen whose properties you wish to modify in the legend.

(A rectangle will appear around the pen to indicate that it has been selected.)

2.   Right-click the pen.

A shortcut menu is displayed.

3.   Depending on whether you wish to change an option that can be toggled on and off or an option that requires a setting:

•   Toggle options on and off by clicking on them in the shortcut menu.

•   Click on Properties to open the properties dialog, where you can adjust settings.

(Click title to expand text)

 Scale Range Min & Max

Select this option to display the minimum and maximum scale values configured for this analog pen along the y-axis of the graph.

The Track Tag Scales checkbox should be checked indicate whether the scales configured for the associated tag should be used as the minimum and maximum scale range values on the graph, or unchecked to enable a custom set of scale range values to be used for the scale range values.  See Scale Range Min & Max for more detail.

The Style drop-down list adjusts the vertical scaling to one of three options:

•    Linear – standard scaling

•    Logarithmic – typically used for

•    Square Root - Square roots are commonly used to linearize flows derived from differential pressure signals.  This technique is often used in for steam flow measurements where an orifice plate (a restriction) is placed in a pipe & the pressure difference is measured across it.  The flow is then a function of the square toot of the pressure

Opens the Select Color palette from which you can select a new color to use for the pen plotting this tag.

VTS will automatically assign colors to your pens, but you may wish to select your own if your application uses color to denote certain types of information (e.g. green for pumps, red for tank levels, etc.)

Use this spin box to select a new line style with which you wish the data associated with this analog pen to be plotted. There are 5 available line styles from which to choose. A preview of the configured line is displayed below the spin box.

Use this spin box to select a new line width with which you wish the data associated with this analog pen to be plotted. There are 9 available line widths from which to choose. A preview of the configured line is displayed below the spin box.

You can un-select this option if you wish to hide the tag’s data from the plot.  This can be useful when you want to focus on the data from other tags without needing to remove this one from the tag selection set.

When checked, each alarm setpoint associated with this tag will be displayed on the graph as a horizontal line across the graph.

At least one of these options must be selected; otherwise no line will be drawn for the selected tag.

Given a graph showing a day or week’s data, each step along the X-axis may represent a large number of data points.  If Plot Peaks is selected, the minimum and maximum data values recorded for each step will be shown, producing a banding effect in the graph. 

If Plot Average is selected, the pen will show an interpolation of the data values across the step. The Plot Average option produces a smoother curve but may hide value spikes from view.

You might not see a noticeable difference between the two options for a tag whose value varies slowly, or for graphs that are able to show most of the tag’s data points.

Select this option to enhance the legend by displaying the description configured for the analog tag.

Select this option to enhance the legend by displaying value of the tag for any selected position in the graph.  As you move your pointer across the graph, the value shown will be that matching the time within the graph that the pointer is currently hovering over.

Select these options to enhance the legend by displaying either or both of the tag’s minimum and maximum values as recorded within the displayed time period on the graph.

Select this option to enhance the legend by displaying the average of the tag’s values as recorded within the time period currently displayed on the graph.

Select these options to enhance the legend by displaying either or both of the tag’s configured low and high scale ranges. Note that these match the values shown in the Min and Max fields at the top of the properties dialog, which are not necessarily the same as the tag’s minimum and maximum scaled process data values.