Caution

This is the documentation for the current development branch of the CometVisu. It is possible that some of the described features are not yet available in the current release.

Also there might be lots of errors in this documentation as some parts of the content have been translated by an online translation service.

Address groups - Calculating with address values

Author: Tobias Bräutigam

Available since: 2023

A <cv-address-group> can be used to perform calculations with the numerical values of several <cv-address> elements. Using the following simplest example the two values of the group addresses 1/1/0 and 1/1/1 are added together and the resulting value can then be displayed in a widget.

Hint

If the calculation results in an erroneous result (e.g. when dividing by 0), an empty result is reported. In this case, the <cv-address-group> attribute data-valid="false" will be added.

<cv-address-group operator="+">
    <cv-address transform="DPT:7.001" mode="read">1/1/0</cv-address>
    <cv-address transform="DPT:7.001" mode="read">1/1/1</cv-address>
</cv-address-group>

The following basic calculations are possible: addition operator="+", subtraction operator="-", multiplication operator="*" and division operator="/". In addition, the result can be rounded to an integer round="true" and/or multiplied by a factor factor="100".

Nesting can also be used to make more complex calculations. For example, the result of the formula round(100.0 * (1/1/0 - 1/1/1) / (1/1/2 + 1/1/0)) can be displayed in a :ref: ‘Info widget<tile-info>’.

<cv-info format="%d%%">
    <cv-address-group slot="address" operator="/" round="true" factor="100">
        <cv-address-group operator="-">
            <cv-address transform="DPT:7.001" mode="read">1/1/0</cv-address>
            <cv-address transform="DPT:7.001" mode="read">1/1/1</cv-address>
        </cv-address-group>
        <cv-address-group operator="+">
            <cv-address transform="DPT:7.001" mode="read">1/1/0</cv-address>
            <cv-address transform="DPT:7.001" mode="read">1/1/2</cv-address>
        </cv-address-group>
    </cv-address-group>
<cv-info>

Hint

It is always better to do such calculations in the backend. The <cv-address-group> should only be used if this is not possible.

Element	Attribute
	Name	Content	Description
cv-address-group	operator	+, -, * or /	Math operator used for calculation.
	round	true or false	Round the result.
	factor	float	Multiply the result with this value.