Glossary · Automation fundamentals, platforms and components
Acknowledgment (alarm)
Also known as: Acknowledgement, Alarm acknowledgment
German: Quittierung
In alarm management, an acknowledgment is the operator action that confirms an alarm has been noticed. Acknowledging changes the alarm state, for example stopping the flashing or horn, but it does not remove the cause of the alarm.
- Automation components
- Standards
- Process industry
In one sentence
An acknowledgment is the operator action confirming that an alarm has been seen; it changes the alarm state but does not fix the cause.
Example
On a filling line HMI, the operator presses the acknowledge button; the red flashing alarm turns steady red and stays until the low-level condition in the tank is gone.
How it applies
- Engineering: Alarm classes define whether an alarm must be acknowledged, whether it latches, and whether acknowledgment is possible before the condition clears. ISA-18.2 and IEC 62682 describe the alarm states behind this.
- Operation: Acknowledging tells the system and other operators that someone has taken note. It is not the same as correcting the fault or resetting the machine.
- Documentation: The operating manual should state for each alarm class what acknowledging does, who may do it and what action must follow. Troubleshooting topics should describe the cause and the remedy, not only "acknowledge the message".
Acknowledgment vs. reset
An acknowledgment confirms that an alarm was perceived. A Reset function returns a machine or safety function to a state from which it can be restarted, typically after the cause has been removed. Many HMIs place both buttons side by side, so instructions must name them precisely and never suggest that acknowledging makes the machine safe.