Trend Chart Window Overview

The

Trend Chart

window is a graphical display which is capable of displaying both digital and analog data for up to 8 tags. The chart window includes features for running and stopping the trend in the controller, configuring chart display properties, and viewing sampled tag data.

At the top of the Trend Chart, the trend control bar is used to start and stop data sampling in the controller, view trending errors, save or delete captured trend logs, or view a specific capture. The control bar also provides information about the state of the trend in the controller, as well as data collection and sampling information.

A typical chart display with the default settings and at least one tag configured also includes a Line Legend, Chart Title, Display Pen Values field, X and Y axis scales, and scroll buttons.

The

Line Legend

provides information on the pen color, tag name, an engineering units description, and Y-axis range for each tag. Double-click any of the

Line Legend

fields to modify their settings.

The

Chart Title

and current date are displayed directly below the

Trend Control

bar. By default, the title is the same as the trend name in the

Controller Organizer

. Double-click the

Chart Title

to modify the entry.

Tag data values are plotted onto the chart relative to the X-axis and Y-axis scale options specified in the chart properties. While the trend is running, the

Display Pen Values

field is always updated to indicate the current tag data values. Note that double-clicking on the X-axis invokes the

X-axis

tab of the

Chart Properties

dialog; double-clicking on the Y-axis invokes the

Y-axis

tab.

Scroll buttons provide the ability to scroll backward and forward along the X-axis timeline to view stored pen values. The timespan which can be viewed is primarily dependent on the Buffer Size for Extra Data specified in the

Chart Properties Options

tab, and the

Sampling Period

specified in the

Sampling

tab. When you use the scroll buttons, chart scrolling is automatically paused; click the Pause button to resume scrolling.

When selected in the

Chart Properties Options

tab, a

Value Bar

may be activated on the chart display by clicking anywhere within the grid. The

Value Bar

identifies the pen values for the current location on the grid. Once activated, the

Value Bar

may also be used to scroll between sampled data points on the chart by pressing Ctrl plus the Right or Left arrows on the keyboard.