onstate

Onstate, or on state, is a term used across engineering and computing to describe the condition in which a device, circuit, or system is active, enabled, or conducting. It is typically contrasted with off-state, idle state, or standby state. In digital electronics, the on-state corresponds to a high logic level and to voltage present at a node or output. A switch, transistor, or relay is in the on-state when current can flow through its path, enabling the connected load. In power electronics, a switch is on when its conduction path is closed and power is delivered to the load.

In software and user interfaces, an on-state denotes a feature, setting, or toggle that is enabled. A switch control may appear as on and display a distinct color or indicator to signify activation. In energy management and instrumentation, devices report whether outputs are in the on-state; power consumption generally increases when in this state.

Terminology varies by field: “on state,” “on-state,” and “Onstate” may appear in different sources or branding, but the underlying meaning remains active or engaged. The term is often part of broader state models of systems, including state machines and control logic.

See also: off state, standby state, operational state, state machine, binary logic.