Creating virtual Math element

Description

The virtual "Math" sensor allows you to calculate the value according to the data of arbitrary sensors.

Adding the Math virtual element

To create a "Math" element, press add button "" inside the "Group tree" or "System tree" menu. Then choose "Math sensor". A modal window will appear:

Click on the "Math sensor". Math element form will be opened:

Fields in the form available for change:

#

Name

Description

#

Name

Description

1

Name

Created element name

2

User defined type

Defines the icon to be displayed in the "System tree"

3

Units of measurement

The unit of measure in which the value is displayed in the "System tree"

4

Minimum value

Determines the minimum measurement range, when the value is out of range, the sensor goes into "Not connected" state

5

Maximum value

Determines the maximum measurement range, when the value is out of range, the sensor goes into a "Not connected" state

6

Alarm and warning levels

Defines the alarm and warning thresholds, as for other sensors, see Sensor configuration

7

Hysteresis

Option of setting the hysteresis state, see Sensor configuration

 

The configuration of data sources is available in the "Additional" tab:

Fields in the form available for change:

#

Name

Description

#

Name

Description

1

Expression

Function of the form f (x). To calculate the indirect value of the sensor is possible to use an arbitrary expression, which are permissible "(", ")", as well as:

  •  

    • operators: "+", "-", "*", "/", "%" (remainder of the division), "^" (exponentiation);

    • functions: "abs","sqrt","exp","ln","log","sin","cos","tan","asin","acos","atan";

    • constants: "pi" (3.1415926...), "e" (2.7182818...);

    • point is used as decimal separator (3.14).

        For example: "0.1*x+0.5"

2

Polling period

Defines the update time of the sensor value

3

Add variable

Allows to add a new variable

4

Variable

Specifies a unique variable name A - Z, names cannot be repeated

5

Corresponding sensor

Determines the sensor whose value is used in the calculations

6

Delete the variable

You can use up to 26 variables with the names A - Z. Each variable can be associated with its own sensor, including the Math sensor.

Warning

If any of the sensors used as a variable source is not available, then the Math sensor will be in a "not connected" state.