Derived Variables

A Derived Variable computes its value from one or more other variables using a formula, rather than coming directly from a device. Useful for calculations like power factor, efficiency ratios, or converted units that combine multiple raw readings.

Creating a Derived Variable

1. From the top bar, click Admin.
2. Click Devices.
3. Select the specific device.
4. Click New Variable.
5. Choose Derived.

Then fill in:

Field	Description
Name/Label	A descriptive name or label for the variable.
Variable ID	A unique identifier for the variable. No spaces — letters and numbers only.
Data Type	The data type for the variable — Float/Number, Text, Boolean, or Increment Number.
Derivation Formula	The expression used to compute this variable’s value from other variables.
Unit	The unit for the computed value (e.g. °C, kg).
Description	A description for the variable.
Decimal Precision	The number of decimal places to round the computed value to.
Widget Color	The color used to represent this variable in dashboard widgets.
Tags	Relevant tags for this variable.

Examples

Derived Variable	Formula	What it computes
Average Voltage	($R_VOLT + $Y_VOLT + $B_VOLT) / 3	The mean of the three phase voltages, useful when you want one number instead of three separate gauges.
Total Current	$R_CUR + $Y_CUR + $B_CUR	Combined current draw across all three phases.
Energy Cost (Today)	$kwh * 8.5	Converts raw energy consumption into cost using a fixed per-unit rate.

Tip

Reference other variables using $VARIABLE_ID — the dollar sign is required, and the ID must match the referenced variable’s Variable ID exactly (not its Name/Label).

Notes

• Derived Variables recalculate automatically whenever the variables referenced in their formula update.