Configure display options for a tag

You can configure the pen style, value axis scale, value display options, and time offset for each tag in the chart.

To configure display options for a tag

1. In the Tag List pane, do one of the following:

   • Right-click on the name of the tag and then click Configure.

   • Double-click on the name of the tag.

     The <ServerName:Tagname> dialog box appears with the General tab selected.

     

2. In the Pen Configuration area, configure the appearance of the curve for the selected tag.

   Color	The line color of the tag. Click the colored square to select the color from a palette or define a custom color.
   Width	The thickness of the trend curve.
   Style	The style of the trend curve. For example, a solid or dashed line.

3. In the Value axis range area, configure the limits for the value axis on the chart.

   Top	The maximum axis value for the tag, in engineering units.
   Bottom	The minimum axis value for the tag, in engineering units.

4. In the Type list, select the type of trend curve to draw. Options are Auto, Line, Step line, and Point.

   A line curve is best suited for continuously-changing analog data. A step-line curve is best suited for discrete data and for analog data that is not continuous. By default, the line curve trend is selected for the summary tags.

   When you select the Auto option, the curve type is determined as follows:

   • For tags retrieved from a version 9.0 or a later Historian, the type is based on the tag’s effective interpolation setting, which may be specified in the Trend application’s retrieval settings or on the Historian. Tags that use stair-step interpolation are trended as a step line, and tags that use linear interpolation are trended as a line.

   • For tags retrieved from earlier Historian versions, the curve type is based on the tag type: step line for integer tags, and line for real tags.

     The following illustration shows the same data drawn using each type of curve. The line curve is shown in green, the step line curve is shown in orange, and the point curve is shown in red.

     

5. From the Format list, select how the values for the tag appear, either in decimal format or scientific format.

6. From the Decimal places list, select the number of decimal places to show for the data value of the currently selected tag. This applies only to analog tags. Valid values are 0 through 15.

7. Select Auto Precision to have the number of decimal places set automatically based on the value range.

   Note: Auto Precision is enabled by default. When auto precision is enabled, the Decimal places field is read-only.

8. Configure either the time offset or start time for the data.

   For more information on time offsets, see Absolute or relative times.

   Time offset	Shown only for absolute mode. The amount of time that the trend curve of the currently selected tag will be shifted from the actual time. For information on the offset notation, see Time offset formats.
   Start time	Shown only for relative mode. The starting time stamp for the tag data in the chart.

9. Click OK.