Signal Plot

Use the Signal Plot (Figure 1) to plot Vehicle Spy signals in real time.

Figure 1: Plotting signals with the Signal Plot feature.

Signal Groups

The Signal Plot feature uses signal groups, or collections of signals, to plot. New groups can be created by clicking on the button, or removed using the button (Figure 1:). Signal groups are edited by clicking the Select Signals button and using the Expression Builder. To choose a different signal group, select it from the drop-down list to display that group in the plot.

Note that the same signal groups are shared between the Signal Plot and Signal List features in Vehicle Spy.

Signal Plot Controls

The Plot Signals button (Figure 1:) creates another Signal Plot window. The Logging button (Figure 1:) opens the Logging view; logging status is displayed just below the button, as shown in Figure 1.

The Signal Plot tool bar (Figure 1:) provides various features for displaying and saving data. Table 1 describes each of the Signal Plot toolbar controls. The data plot is seen in the bottom section of the window (Figure 1:). The plot axes (Figure 1:) can be stretched or zoomed by clicked and dragging them.

Table 1: Signal Plot Toolbar Controls

Signal Plot Tool	Description
Track	Enabled by default, so the plot scrolls to show the most recent data; press this to resume scrolling after pressing the Pause button.
Pause	Stops scrolling so the display can be reviewed.
Scroll Axes	When selected, dragging the mouse on an axis will scroll the axis in that direction.
Zoom Axes	When selected, dragging the mouse on an axis will zoom the axis proportionally.
Zoom Out	Zooms out from the plot.
Zoom In	Zooms in on the plot.
Zoom Box	After clicking this button, left-click and drag a box around an area to zoom in, showing only what was surrounded by the box.
Cursor	This button enables cursors that can be dragged to make measurements from the plot.
Properties	This button brings up a dialog to configure the plot.The maximum number of plot points per signal can be changed here; the default is 10,000. Note that setting this value too high will create problems if the computer does not have enough memory. As a point of reference, 50,000 plot points with 6 signals will use about 4.8 MB of RAM.
Copy chart	Copies a bitmap of the plot to the Windows Clipboard so it can be pasted into another application.
Save Chart	This allow the chart to be saved as a .BMP, .PNG, .EMF, or .JPG file.
Print Chart	Opens a dialog to let you print the plot.
Cursor Mode	This drop-down box allows you to select what type of measurement is made with the cursors on the plot.
Time Span	This entry controls the number of seconds of data displayed on the graph.