Emerson E2 operation manual Graph View, Zooming In and Out

2.Select Log, and the Log screen opens.

Several function keys may be used to navigate the Log view and provide additional information:

• BEGINNING - Move the cursor to the top of the table (the most recently recorded sample).

• END - Move the cursor to the bottom of the table (the oldest sample).

• GRAPH - Displays logged data in a graph format (see Sample Graph View Figure 12-28).

• UPDT DATA - Pressing this key updates the Log View by adding all newly recorded samples to the top of the table.

• EXPD INFO - Pressing this key will display the board/point address or the controller/applica- tion/property address for the point that is being logged.

•Page Up - Scrolls up one page.

•Page Down - Scrolls down one page.

12.11.3 The Graph View

Figure 12-28- Sample Graph View

The Graph view shows logged data in a graphical for- mat with sample times as the X (horizontal) coordinate and sample values as the Y (vertical) coordinate. To access a graph view:

1.Highlight a value from any screen and press to open the Actions Menu.

2.Select Graph, and a graphed view of the selected value opens.

Upon first entering the Graph view for a logged value, all available samples are displayed. The X axis (sample time) ranges from the time and date of the earliest avail- able sample relative to the time and date of the latest sam- ple. The Y axis (sample value) ranges from the minimum sensor reading to the maximum sensor reading.

In the case of an input point log, (e.g., suction pres- sure) assume the Log Group setup specifies Samples as 1000 and Log Interval as 0:03:00. Also assume that the system has been running continuously with no interrup- tions for one week. The X axis would span a time interval starting approximately six days and six hours ago all the way up to the present.

If suction pressure ranged from 18 psi to 25 psi during the time period of the log, the Y axis of the graph would be just large enough to show all samples in the log.

12.11.4 Zooming In and Out

For a more detailed view of a graph, zoom in by press- ing . This results in half of the samples of the current view being redrawn to fill the entire view. Using the above example, the graph would now shows three days and three hours of samples from the middle of the original graph.

Pressing  again zooms in even farther.

Pressing  zooms out, resulting in a graph whose time scale spans twice that of the previous view. This dou- bles the number of displayed samples.

Navigating a Zoomed View

While zoomed in on a graph, only a subset of the total number of samples are visible. To view samples that were recorded earlier or later than those in the current view, press the left and right cursor keys. The availability of ear- lier or later samples is indicated by the presence of arrows at either end of the X (time) axis.

12.12Naming Conventions for E2 Controllers, Applications, and Points

•Do not name applications, controllers, or points with all numeric characters.

•Do not use colons (:) in the names of applications, controllers, or points.

Naming Conventions for E2 Controllers, Applications, and Points Operator’s Guide to Using the E2 • 12-17