History Chart

This chart shows historical data values for the related asset. A history live chart appears with asset data when you select to chart a current data item or historical data item for an asset (from the Asset dashboard).

In the Configure this chart properties, you can select to view data in two formats: as raw, actual data (actual data items and values as they were sampled) or interval data (data interpolated to show a trend of data values over time).

o Maximum Samples (all values) - this chart shows historical values as actual data values captured in the past. Instead of specifying Start and Interval times (as you would do for viewing interval historical values), you specify a start and end time, and the number of samples when you read these values. The Platform retrieves all data values logged to the database that fall between the Start and End Times, up to the threshold value specified by the maximum number of samples.

o Interval - this chart shows an interpolated replay of historical values. The Platform uses the specified start time and sample values to calculate and return values for each interval, interpolating the values in its Platform to match your requested intervals.

You can modify the format and layout of the chart to show data generated in other timeframes, to show the data aligned or overlapping, and so on.

Annotation chart

In addition to viewing historical asset data, you can track user actions for the asset in the annotation chart. Any annotations (notes, messages, alarms, actions) that occurred in the Platform in the same timeframe as the history chart appear in the annotations chart. You can point to a specific charted annotation to view its properties. You can add a new note annotation to identify a data marker; this will be saved to the database with the asset's information (see below for "How to add data markers for strip chart displays").

Procedures for History charts

In addition to the operations you can perform on all charts, operations specific to the History charts include the following: select the data items to trend in the window, and use the zooming and tracking tools to view and analyze the data; view specific data value trends in the chart; apply markers to areas of interest in the chart; view annotation activities in the Platform. To learn how, click the procedure title to display the details; click the title again to hide the details.

To specify the format for the chart

1. Under Configure this chart, type the start and end times for the data values to show in the window.

2. Do one of the following:

§ Select Max. Samples and type the maximum number of data points per data item to show in the chart (for a raw data/actual history replay).

OR

§ Select Interval and type the number of minutes' worth of data values to show in the chart.

For example, the following settings show asset values logged from 10 days ago until yesterday:

$image\example_historytrendsettings.gif$

3. Select whether to display the charted data values on aligned or overlapping y-axes.

4. Click Refresh. The chart is redrawn with the properties you specify. Note that the selected time is set to the middle of the chart window.

To view information in the annotation chart

1. Set the start and end times for the Platform / asset activity you want to track. (See step 1 of "How to specify the format for the chart".)

2. View the annotation markers as they appear in the annotation table. The location of each marker on the chart indicates the time that each activity occurred. The markers identify the following activities for the asset:

$image\icon_historychart_annotation_action.gif$ - An action was performed.

$image\icon_historychart_annotation_note.gif$ - A note was added to the Platform.

$image\icon_historychart_annotation_alarm.gif$ - An alarm was generated.

$image\icon_historychart_annotation_event.gif$ - An event was generated.

3. Point to an annotation marker to view its properties.

To add data markers for strip chart displays

1. Set the start and end times for the Platform / asset activity you want to track. (See step 1 of "How to specify the format for the chart".)

2. In the chart display, click where you want to add a data marker. The marker appears on the closest data point. You can add up to two markers per chart display.

To add a second marker, right click the chart. To move either marker, click in the chart with the related mouse button. For example, to move the first marker, click the destination point with the left mouse button: to move the second marker, click with the right mouse button.

To clear all data markers, press SHIFT and click in the chart display.

Now you can add notes to each marker to identify its importance. Each marker note is saved to the Platform, with the corresponding asset.

To add notes to markers

1. For a selected marker, click $image\serviceapp_chartnewmarkernote.gif$ above the annotation chart.

2. In the displayed Add Note Dialog, type the note you want to add for the marker and click OK.

The data marker notes you add here will be saved to the database with this asset's records.

To clear all data markers, press SHIFT and click within the chart display.

Tip

Aligned value display is useful if the values are of the same units; Overlapping value display is most useful if the values are of different units.