Glossary · System coordination, integration and orchestration
Mode transition
Also known as: Mode change, Mode switchover
German: Betriebsartenübergang
In industrial automation, a mode transition is the change of a machine or system from one operating mode to another, for example from automatic to setup mode, including the conditions that must be met and the actions performed during the change.
- System integration
In one sentence
A mode transition is the change from one operating mode to another, with defined preconditions and actions such as stopping motion or resetting states.
Example
Switching a machining center from automatic to setup mode stops the program at a defined point, activates reduced speed and requires the enabling device for axis movement.
How it applies
- Engineering: Specify for each allowed transition the preconditions (machine stopped, doors closed, authorization), the actions (reduce speed, release axes) and forbidden transitions. According to machinery safety practice, a mode change must not by itself start hazardous motion.
- Commissioning: Test every transition, including interruptions during the change and transitions triggered from different control locations.
- Operation: The active mode must be clearly visible; ambiguous mode indication is a known cause of incidents.
- Documentation: Describe each transition as a procedure in the operating instructions: who may perform it, the steps, what the machine does and what the operator must check afterward.
Mode transition vs. state transition
A State transition is any change in a state model, such as from Idle to Execute in a PackML state machine. A mode transition changes the operating mode, which determines which states and functions are available. A machine can go through many state transitions within one mode.