Using Trend Curves

At a Glance

The Trend Curves view is a fitted representation of analogical variable. It allows comparing different curves with a precise scale. In addition, the Probe Mode displays value of each variable at a specific date.

Displaying the Variable Trend Curve

To display the variable trend curve, proceed as follows:

Step	Action
1	Select the variable in the list on left hand side of the chronogram.
2	Select Display Trend Curve in the context menu, by right clicking on the variable.

If the Chronogram view is displayed in full screen, this action will automatically split the screen to show at the same time Chronogram and Trend Curves.

Hiding the Variable Trend Curve

To hide the variable trend curve, proceed as follows:

Step	Action
1	Repeat previous actions to display the Trend Curve.
2	Select the variable in the list on left hand side of the Trend Curves.
3	Select Hide the variable in the context menu.

If after this action, no trend curve is displayed, then the Trend Curves view is automatically hidden.

Navigating Between Chronogram and Trend Curves

Trending Tool allows navigation between Chronogram view and Trend Curves view.

You can execute the following actions, by selecting the Display menu, in the view context menu of Chronogram or Trend Curves:

Step	Action
1	Hide: Hide the current view.
2	Screen Split: This action is available when a view is in full screen. It allows displaying simultaneous the Chronogram and the Trend Curves view. The occupancy ratio by default between the two views can be modified in the display dialog box.
3	Maximize: This action is only available when the window is split. It shows in full screen the current view.

Viewing Diagram Options

The Trend diagram tab in the Display options dialog box enables you to modify the display options of the trend diagram. The dialog box options are listed below in the table.

Dialog box options	Description
Use PLC Time for reference	If this option is enabled, reference time for events is PLC time based and not PC time based.
Display in milliseconds	If this option is enabled, durations are displayed to an accuracy of 1ms instead of 10ms. This option doesn't improve the accuracy of the information coming from PLC at the time of the acquisition.
Optimize the durations display	On the trend diagram, this option allows you to display only status durations that are compatible with the display scale rather than all durations.
Trend diagram view area	In Trending Tool, the split settings between the trend diagram and trend curves are saved in the module. This option allows you to customize Trending Tool. You can set up these options: Value for new module: define the size of the trend diagram in the window (as a percentage) when viewing a new module. Value for Screen Split action: define the size of the trend diagram in the window (as a percentage) after this action
Background color	You can customize display options by selecting background colors for the trend diagram and trend curves.
OK	Close the dialog box and apply the changes made.
Cancel	Close the dialog box without applying any changes.
Help	Open a window featuring an online help related to the dialog box properties.

Using Curve Graphical Representation

By default, module variables have different representations. If a variable is present in different modules, then, its representation may be different in each module. The representation is able to be customized with the properties dialog box.

The Properties dialog box shows Trending Tool variable characteristics. It contains two tabs: Description and Display.

The Display tab allows you to customize the graphical representation of trend curves. The different properties of the Display dialog box are listed below:

Type	Two choices are available: a standard representation (two points linked by a line) or a stepped representation.
Color	Curve color.
Line size	Curve thickness.
Style	Hachure style.
Point	Type of point used to show the measurement points.

The Display scale tab dialog box variable characteristics are listed below:

Display Scale
Display the scale	Show or hide the variable scale.
Upper Bound	Enable maximum scale value setting if manual is checked, otherwise the maximum statistic value is used.
Maximum statistic value	Show the maximum value that the variable is able to take for the duration of the recording.
Lower Bound	Enable minimum scale value setting if manual is checked, otherwise the minimum statistic value is used.
Minimum statistic value	Show the minimum value that the variable is able to take for the duration of the recording.

Modifying the Scale

To show or hide the variable scale, proceed as follows:

Step	Action
1	Select the variable in the list on left hand side of the Trend Curves.
2	Select Show the scale in the context menu, by right clicking on the variable.

The lower and upper bound can be modified on the properties dialog box.

Horizontal marks displayed behind trend curves correspond to the most right of displayed scale.

You can change the order of the scales by doing a drag and drop.

All actions are available by right clicking on the variable on the left hand side of trend curves. They are also available by right clicking on the scale.

Using the Probe Mode

The Probe Mode allows you to display values for a precise date. Thus, the values, located at the intersection between probe and curve, are shown in the display zone of the scale.

To show or hide the probe, proceed as follows:

1	Click right on the trend curves.
2	Select the Probe Mode item in the context menu.

To move the probe, proceed as follows:

1	Move the mouse cursor on the probe
2	Press and maintain the mouse left button and move it