Database

What are Fields?

Creating a new Field

To create your own field, open any device and navigate to its configuration area using the tab bar.

There you scroll down a little until you see the "Fields" panel:

Just click on the blue button "Add Field" to create a new field. The following dialog should appear:

Name

This is the displayed, readable name as it can be used in the portal, e.g. to give widgets on dashboards a title or in other places.

You can change this name at any time later.

Identifier

The identifier is a unique designation that is used for storing data in the database.

Once the field is created, the identifier cannot be changed. If you still want to change it, you must delete the field.

Types

We support following field-types:

Integer

Stores integers like 1234567.

Float

Stores numbers with decimal places, even floating point, such as 1234.56. This type is suitable for storing values with decimal places, such as

  • Temperature

  • Pressure

  • Air quality

String

Save complete character strings. like Sensor OK, Your own payload information, A83B8CFH38420. These are being stored unprocessed in the database including a timestamp.

Use this data type to store e.g.:

  • status messages

  • events

  • Your own payload data

In addition, strings can be used in conjunction with mapping fields to convert numeric sensor values into a status via look-up table.

Boolean

Via Boolean fields you can store measured values of digital signals that are either only 0 or 1, or True or False. Use these for:

  • Status-Signals of digital Inputs

  • True / False conditions

  • Events

Counter

You can use a counter field to measure the relative change of an absolute value over time.

Every time a measurement is transmitted, we calculate and store the relative change to the previous recorded value.

If the change is negative, i.e. the transferred value is smaller than the previously transferred value, we assume that the counter has re-started counting from 0 and store the transmitted value instead of the relative change.

This ensures that we can display the consumption as a relative change even after resetting an external meter source.

A counter field can only be used to measure positive changes. If you want to measure a negative change, you must first invert the measurement using a mapping field and a negative scaling factor (for example, -1).

Currently, the counter field type only works with integers. A support for floats will follow.

GEO / Location

Unit

Formula

Mapping Fields

Any mapping fields can be added to any field in the database. These calculate the content of the original field into a desired target value using various functions. The conversion is performed each time a new measurement value is written to the base field.

Mapping fields also store their contents in the database.

Usage

Mapping Fields can be used for the most diverse tasks. Some of these are, for example:

  • Simple scaling of a measured value using a factor

  • Mapping of a value range to the value range of a sensor

  • Conversion of numeric value to a string (for status messages based on a number) via Look-Up-Table

Examples

Under the following links you will find some best practices and examples for different tasks.

Add a new Mapping Field

Mapping fields can be created by adding them to a base field. To do this, open the drop-down menu of a field and click on "Add Mapping Field".

After you have clicked the button, the following modal appears:

The modal itself is divided into three different areas:

  • Field Configuration (RED)

  • Mapping Type (GREEN)

  • Mapping Settings (BLUE)

Field Configuration

This area is identical to the field configuration of a basic field. Here you determine name, identifier, type and unit. Read more about this in the previous section.

Mapping Type and Settings

The tab bar (Green) must be used to define the type of conversion. A checkmark behind the active element indicates which type of conversion is active.

The settings for the respective conversions are described in the following sections. They are located in the area (Blue) below the tab bar (Green).

Linear Scale

Use this option to convert a value range to a target value range.

In linear scaling, the measured value is converted based on a scale. You must enter two base (Source) and target (Target) values here.

Use Boundaries

If you activate this option, the value resulting from the conversion remains within the scale (Target).

If the option is deactivated, negative values or values that lie outside the specified scale (Target) can result, but still be scaled based on the entered values (Target).

If you need a simple conversion based on a factor, use the option "Factor".

Source

This is the base-scale with which you specify the value range that is to be scaled to a new value range.

The two input fields below each other can be understood as "From" and "To" and describe the original value range.

Target

This describes the target value range.

Again, both input fields can be understood as "From" and "To". Enter the value range into which the original value range should be converted.

Offset

The offset can be used to achieve a static change of +/- the value specified in the text input field. It's added to the resulting value after the conversion has taken place.

To subtract an offset, enter a negative value in the Text Input field.

Visual check

To the settings you will find a graph that visually represents the conversion of the value range. Here you can visually check your input again.

Save

If this step was successful, the newly created mapping field is displayed as a subordinate field of the original field.

Limitation of types

Even if the choice of type is not limited. The "Linear Scale" option works only with the following types:

  • Integer

  • Float

  • Counter

Lookup Table

Boolean

Factor

The "Factor" option allows you to convert the output value using a factor. The output value is multiplied here by the specified factor.

Limitation of types

Even if the choice of type is not limited. The "Factor" option only works with the following types:

  • Integer

  • Float

  • Counter

Save and Create

To create the mapping field, confirm your entries with the "Save" button. Only after you do this the field is created.

Using Formulas

What?