Linear Gauge+

Overview

When to use it

Use Linear Gauge+ when you need to:

• Show a value against a scale, as a pointer or as a bar filled from the scale minimum.
• Color the scale by the limits of the value (AF limit traits or limits you type), so normal, warning, and alarm ranges are visible.
• Put several values on one shared scale in a compact horizontal or vertical layout.
• Show a summary of a period, such as the average, instead of the live value.
• Show an AF attribute in another unit of the same kind, such as degrees Fahrenheit instead of Celsius.

Choose Radial Gauge+ when a circular gauge fits the display better. Choose KPI Card+ when the value needs a target comparison or a sparkline, and a trend when the operator needs to see how the value changed over time.

Before you begin

• Use a numeric PI Point or AF attribute. Several data sources can share one gauge; give them compatible units and ranges.
• For colored ranges, use AF attributes that have limit traits (LoLo, Lo, Hi, HiHi), or type the limits yourself in the multi-state pane.
• To show another unit, use an AF attribute that has a unit of measure. A PI Point carries its engineering units as plain text and cannot be converted.

Add and set up the symbol

1. Select Linear Gauge+ in the PI Vision symbol gallery.
2. Drag a numeric data source onto the display. A vertical gauge with a marker appears. The scale takes its minimum and maximum from the range of the attribute in AF.
3. Resize the symbol so that it is wider than it is tall.
4. Right-click the gauge and select Configure Linear Gauge....
5. Under Scale, open Layout and select HORIZONTAL for Orientation.
6. Under Trace Options, open Label and select Name + Value for Show.

The gauge shows a horizontal scale with the marker at the current value and the name of the data source below it.

Common tasks

Show the value as a bar

Use a bar when operators should see how full or how far along a value is, rather than where a pointer stands.

1. Right-click the gauge and select Configure Linear Gauge....
2. Under Trace Options, select the data source in the list.
3. Select BAR for Type (1).
4. Select RANGE for Color (2) so the bar takes the color of the range that holds the value. Select CUSTOM for one fixed color.

1. Under General, open Container and select a Type (1), for example Rounded.

The bar fills from the scale minimum up to the current value inside the container. Normal, Rounded, and Thermometer draw a frame around the bar; None draws the bar alone. Use Width under Bar to make the bar thicker.

Color the scale by limits

Use this when operators must see whether a value is normal, in a warning range, or in an alarm range.

1. Right-click the gauge and select Add Multi-State.... When the gauge already has multi-state ranges, the command reads Configure Multi-State....
2. Read the list of states. For an AF attribute with limit traits, each limit appears with its value (2) and a color box (1).
3. Select a color box and pick a color from the palette. In this example the lowest and highest ranges are red and the next ranges are orange.

1. Right-click the gauge and select Configure Linear Gauge....
2. Under Rangebar, check that Show is ON (1). The colored ranges now run along the scale.
3. Set Highlight to ON (2) to dim every range except the one that holds the current value.

The range that holds the value stays bright and the others are dimmed. If several data sources share the gauge, the check box under Highlight selects the data source that decides which range is active.

For a data source without AF limits, the multi-state pane shows a box and an Add button instead. Type a limit and select Add, then edit or remove limits in the list below. To spread the ranges as a gradient, use Gradient under Rangebar; it is available on a horizontal gauge and cannot be combined with Highlight.

Set the scale range and ticks

Use this when the default scale is too wide for the values you watch, or when the tick marks should match your limits.

1. Right-click the gauge and select Configure Linear Gauge....
2. Under Scale, open Range and select CUSTOM for Range (1).
3. Enter the Maximum (2) and the Minimum (3), for example 80 and 20.

1. Open Major and select Multi-state boundaries for Tick spacing (1).

The scale now runs from 20 to 80 with a labeled major tick at every limit. Select Fixed interval for Tick spacing to enter your own interval, or Automatic to let the gauge choose. Set Invert scale to ON under Range to reverse the direction of the values.

Show an average or other summary instead of the live value

Use this when the gauge should report a period, such as the average of the last two hours.

1. Right-click the gauge and select Configure Linear Gauge....
2. Under Trace Options, select the data source and select Average for Value Type (1). The list also offers Maximum, Minimum, StdDev, pStdDev, and Range.

1. Under Data Retrieval, select Duration and offset for Start- and Endtimes (1).
2. Enter the Duration (2), for example 2 hours.

The marker moves to the average of the two hours before the display end time. Without step 3 and 4 the summary covers the display time range. Nothing on the gauge says that the value is a summary, so name the period in a title or a text label next to the gauge.

Show the value in another unit

Use this when readers expect a different unit than the one stored in AF.

1. Right-click the gauge and select Configure Linear Gauge....
2. Under Trace Options, select the data source.
3. Select a unit from Display unit (1), for example degree Fahrenheit (°F). Default follows the unit set in AF.

The marker, its label, the scale, the scale labels, and the ranges from AF limits switch to the new unit. The list offers units of the same kind only. If the converted value loses detail, choose more decimals under Numbers.

Important: A CUSTOM minimum and maximum and limits you typed in the multi-state pane are read in the displayed unit and are not converted. Enter them again after you change Display unit. The Display unit row is unavailable for PI Points and for attributes without a unit of measure.

Use the symbol

• Read the value: The marker sits at the current value, or a bar is filled up to it. When ranges are shown, the range that holds the value tells you whether it is normal, a warning, or an alarm. With Highlight on, the other ranges are dimmed.
• Hover: With the tooltip enabled, hovering over a marker or bar shows its value, and its name when Name is on. Hovering could not be tested in the automated capture, so check it on your display.
• No data: A data source without data shows its label with No Data in the Bad data color, red by default. Change that color in the multi-state pane.
• Stale data: With Stale warning on, an amber clock appears when a live value is stale. Its tooltip lists each affected data source. See Data Quality.
• Units: A pop-up trend or ad hoc display opened from the gauge shows each data source in the unit chosen under Display unit.

The gauge is read-only. It never writes values back to PI.

Configure the symbol

Open the pane with right-click and Configure Linear Gauge.... The sections follow the pane order. Some controls appear only when they apply, for example the Highlight check boxes when Highlight is on.

General

Scale

Rangebar

Available when the gauge has multi-state ranges. Edit the limits and colors in the multi-state pane.

Trace Options

Select a data source in the list first. The settings apply to that data source.

Other sections

Troubleshooting and limitations

Limitation: The scale range and the ranges from AF limits follow the first data source. When the multi-state rules are based on another data source, they stay in that data source's own unit.

Limitation: The title is always centered above the gauge.