Computed widgets & expressions

A computed source derives a value from several tags in real time.

  1. On the widget, choose the computed source.
  2. Define variables, each a { name, deviceId, tag } slot — e.g. a = meter1.power, b = meter2.power.
  3. Write an expression using those names: a + b, (a + b) / 2, v * i, etc.

The widget subscribes to every variable's stream and re-evaluates the formula on each tick. Variables can come from different devices, so you can total a fleet or compute power = volts × amps across two sensors.

More in Dashboards
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Build your first dashboard
Drag widgets onto a canvas and bind them to live device tags.
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