Level Meter

This article applies to versions 4.4.2 and later of IFS OI Explorer. For more, see Release History.

Overview

The Level Meter is used for displaying level measurements against defined limits, called alarm thresholds.

The component changes in appearance when limits/alarm thresholds are exceeded.

The measured value and any of the limits can be fixed or variable, using tags, attribute values, dataset values or a fixed or variable value defined in Studio.

For example, you can configure a level meter to compare the actual value of the selected storage tank's level against limits defined for that tank, or against tags that contain fixed values for the various limits.

Related: Using the Process Controls for users in display mode, Adding a Level Meter style, Pressure Meter, Temperature Meter, Gauge

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Properties of the Level Meter

This section describes what needs to be configured in the Level Meter, in three main sections:

• Minimum, Maximum and Limit Thresholds
• Measured Data
• Appearance

1. Limits Set limits from Low through to High High, as well as a Minimum and a Maximum value. 2. Measured Data Configure the data to measure against the different thresholds. 3. Appearance This section has a number of options for configuring the meter's appearance in Display Mode. 4. Position in Precision Layout This section is available if the component is on a Precision Layout. 5. Position in Grid Layout This section is available if the component is on a Grid Layout.

As well as defining the measured values and limits, you can define a label and units, and you can configure whether to show the measured value and label, alarm indicator and the limits.

Minimum, Maximum and Limits

Choose values that range from low to high, using the Data Selector for each limit in the property panel. These limits define the bands within the level meter: from top to bottom these bands are High High, High, Outside Target, Target, Outside Target, Low, and Low Low.

There are five separate categories of data that you can select for the minimum, the maximum and for each limit: Dataset Column, Ad hoc Calulation, Attribute, Tag, and Value.

Measured Data

Use the Data Selector to configure the data to measure. The measured data is displayed as a vertical indicator (of a set colour), within the level meter. Its highest point marks the value, and is positioned within one of the bands. There are five separate categories of data that you can choose from: Dataset Column, Ad hoc Calulation, Attribute, Tag, and Value.

Appearance

Each of the configuration options can be selected from the five different data categories: Dataset Column, Ad hoc Calulation, Attribute, Tag, and Value, using the Data Selector.

To simplify the explanation, we'll just look at using fixed values.

Label Text: Type a label for the component, which appears on the page in display mode. This should describe the level you are measuring.

Units Text: Type the unit of measure here. In display mode, the unit of measure (for example, Meters) is displayed next to the value.

Decimals: Type in an integer for the number of decimal places for the measured value.

Confidence Threshold: The confidence value of the measured data is measured against this threshold. Both are percentage values. If the confidence value is below the threshold, the Data Indicator appears in display mode.

Show Value: Select this option (set to true) if you want to the measured value and label displayed on the control.

Show Alarm Indicator: Select this option (set to true) if you want alarm indicators on the control.

Show Limits on Hover: Select this option (set to true) if you want limits to appear when the user hovers the mouse over the level meter.

Style: The style you want to apply to the Level Meter component. If you are a Style Administrator, you can add a new Level Meter style.

The Level Meter in Display Mode

The level meter's appearance is partially based on how it is configured in the design mode, and partially based on the measured data and the alarm limits.

Note that the level meter's selected style will also affect its appearance: size, font size, colours, positioning of indicators.

1. Data Indicator Here, the Data Indicator shows Low Confidence Data as the measured data's confidence is lower than the configured confidence threshold for the level meter component. 2. Alarm Indicator This particular alarm indicator shows that the measured data is in the High Alarm band. 3. Limit Values The values for Minimum, Maximum and the different limits can be seen when you hover over the level meter (if Show Limits on Hover is selected). 4. Bands Background colours mark the different bands between the thresholds. High High at the top, matches Low Low at the bottom. High matches Low, and in the style used here, Outside Target matches the Target band. As shown in this example, the band (High)containing the Measured Value is coloured to match the Alarm Indicator. 5. The measured value position The measured value is depicted by a centred line, positioned within its band, according to its value. 6. Measured value The measured value. The decimal points are configured in Decimals. 7. Units This is the text in Units Text. 8. Label This is the text in Label Text. 9. Target Border The target border surrounds the target band, and is coloured in grey, unless the measured value is in the Outside Target band, when it takes on the Outside Target colour.

Alarm Indicator

The Alarm Indicator only appears if Show Alarm Indicator is selected.

The Alarm Indicator is a coloured symbol representing the current state of the measurement, such as the blue triangle on the screenshot below.

Note: The size, colour and position of the Alarm Indicator may vary, depending on the Level Meter's selected Style.

Hover over the alarm indicator to see the tooltip.

The symbol depends on what band the measured value falls into. From highest to lowest bands, here is the key:

	Band	Alarm Indicator	Symbol	Tooltip
	High High	Red Triangle		High High Alarm
	High	Yellow Square		High Alarm
	Outside Target	Blue Triangle		Outside Target
	Target	No Indicator
	Low	Yellow Square		Low Alarm
	Low Low	Red Triangle		Low Low Alarm

Data Indicator

The Data Indicator is a symbol that appears alongside the level meter if there is either Low Confidence Data or No Data.

The data indicator appears in a square background, as a cross if there is No Data, or as an exclamation mark if there is Low Confidence Data.

Note: The size, colours and positioning of the Data Indicator may vary, depending on the level meter's Style.

Sometimes there is no data to measure, for example if the level meter is configured to measure the actual level of a tank, and this attribute value is missing from the selected entity. In this instance, the data indicator shows the No Data symbol, and three Xs mark the place where the value would normally appear.

If the measured data's confidence is lower than the level meter's defined confidence threshold, the data indicator shows the Low Confidence symbol. Data confidence threshold is measured as a percentage.

Note: You need to select a Confidence Threshold in design mode, for this to work.

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Tutorial: Level Meter Updating with Selected Entity

If you're unfamiliar with the process of building pages, read the article Building an Explorer Page.

Watch the video below to see how the level meter's appearance changes as the value is updated.

Note how the value updates after the date/time toggle is selected. When the entities Cooling and Esmonde are selected, the No Data indicator appears. This is because neither of these entities have the attribute used in the measured data.

The tutorial describes how to configure the level meter shown in the video.

Refer to the Level Meter page in the Tutorials workspace, if you have access to this.

There are four steps in the tutorial:

• Step 1. Prepare the new tutorial page.
• Step 2. Update the selectedEntity default value.
• Step 3. Add hierarchy, labels and a current date/time toggle.
• Step 4. Add and configure a level meter.

Note: If you have already completed any of the tutorials listed below, you can skip the first three steps and go straight to Step 4.

• Pressure Meter tutorial
• Temperature Meter tutorial
• Gauge tutorial

 

Step 1. Prepare the Tutorial Page

Note: Before you start the tutorial, prepare a precision layout page in Studio and save it with a suitable name, such as Level Meter.

 

Step 2. Update the selectedEntity Default Value

In this step we're going to assign a value to the selectedEntity page default.

Related: See how to add and configure a Default Value.

1. Open the Default Values panel.

2. Type Jackadder in the selectedEntity value text box.

 

Step 3. Add Hierarchy, Labels and a Current Date/Time Toggle

The hierarchy is for selecting a new entity, and the current date/time toggle is to refresh the data on the page. The labels are just for providing context to the page and can be left out, if you prefer.

Related: Hierarchy, Current Date/Time Toggle, Text Label.

1. Drag a Hierarchy onto the page. Resize it to fit the full height of the page.

2. In the Hierarchy component's property panel, select P2 Corporate from the drop-down list of available hierarchies for the Hierarchy Name.

3. Drag a Current Date/Time Toggle onto the page.

4. In the Current Date/Time Toggle component's property panel, type 3 in the Refresh Rate edit box, so that the page's endTime default is refreshed every three seconds.

5. Drag a Text Label onto the page, to the right of the hierarchy. Widen the label slightly.

6. In the Text Label component's property panel, add data to the label's Content: the selectedEntity variable.

7. Drag another Text Label onto the page, above the current date/time toggle. Widen the label slightly.

8. In the Text Label component's property panel, type Date/Time Toggle in the Content.

 

Step 4. Add and Configure a Level Meter

If you have already completed any of the tutorials listed below, open that tutorial page (for example, Pressure Meter), and save a copy to a new page called Level Meter.

• Pressure Meter tutorial
• Temperature Meter tutorial
• Gauge tutorial

Related: See how to select data for a component using the Data Selector.

1. Drag a Level Meter component to the right of the hierarchy. (If you are using the saved copy of the Pressure Meter/Temperature Meter/Gauge page, first remove the Pressure Meter/Temperature Meter/Gauge component. Update the Default Value for selectedEntity to Jackadder.)

2. Click and drag the edges to widen and lengthen the component.

3. Click on the Level Meter so that the properties appear in the component's panel on the right.

4. Assign tags to the maximum, limits and the minimum of the component. For each separate property, use the Data Selector to select Tag Data.

a) Maximum: Click the drop-down list, select tag MaxValue. Click the drop-down list again to close it. b) High High Limit: Click the drop-down list, select tag HighHighLimit. Click the drop-down list again to close it. c) High Limit: Click the drop-down list, select tag HighLimit. Click the drop-down list again to close it. d) Outside Target (upper): Click the drop-down list, select tag TargetRangeHigh. Click the drop-down list again to close it. e) Outside Target (lower): Click the drop-down list, select tag TargetRangeLow. Click the drop-down list again to close it. f) Low Limit: Click the drop-down list, select tag LowLimit. Click the drop-down list again to close it. g) Low Low Limit: Click the drop-down list, select tag LowLowLimit. Click the drop-down list again to close it. h) Minimum: Click the drop-down list, select tag MinValue. Click the drop-down list again to close it.

 

5. Now use the Data Selector to select the selectedEntity's Tank Levels!Actual attribute value, from the Storage Tank template, to the measured value's Attribute Data.

This assigns the selectedEntity's Tank Levels!Actual attribute value to the measured value: selectedEntity[Storage Tank]:Tank Levels!Actual. selectedEntity is a variable, which the end-user can change by selecting different entities from the hierarchy on the page.

6. Configure the appearance of the level meter. For each separate property, use the Data Selector to select Value Data.

• Label Text: Type in a Value of Storage Tank Levels.
• Units Text: Type in a Value of Meters.
• Decimals: Type in a Value of 2.
• Confidence Threshold: Select the variable Value of confidenceThreshold (this is a page default) .
• Show Value: Select the Value to set it to true.
• Show Alarm Indicator: Select the Value to set it to true.
• Show Limits on Hover: Select the Value to set it to true.

You now have a functioning level meter.

 

Try out the New Component

• Click the Preview button on the Studio toolbar to see what your page will look like in display mode.
• Select the current date/time toggle so that the data can refresh at the configured refresh rate.
• Select a different entity from the hierarchy, to see how the storage tank level changes.

Note how the data updates every three seconds, because of the current date/time toggle.

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Release History

• Level Meter 4.4.1