Industrial Engineer · phase 12 of 16
Run Enable
Hardware or logic condition that must be present before the drive will accept a run command.
The Explain card
- Plain English
- Run enable is a condition that has to be present before the drive will honour a run command. It is usually a hardware input, and often it is tied to a safety circuit.
- Example
- The emergency stop relay feeds the drive's enable terminal. With the stop pressed, the enable drops, the drive ignores every run command, and pressing start on the HMI does nothing.
- Why it matters
- Enable and run are separate on purpose, so a safety function can hold the drive off without touching the control logic. A missing enable is the second most common reason a drive sits there ready and refuses to move.
- Hook
- Permission to run, separate from the request to run.
Where it sits in the deck
Phase 12: VFD Commands, References, and Stopping
Starting, referencing and stopping, including the several very different things a drive can mean by the word stop.
