Glossary · HMI, SCADA and operations
Alarm acknowledgment
Also known as: Alarm acknowledge, Acknowledgement
German: Alarmquittierung
In alarm management, alarm acknowledgment is the operator action confirming that an alarm has been noticed; it changes the alarm's state and usually silences the audible signal, but doesn't clear the underlying condition.
- HMI and SCADA
- Process industry
In one sentence
Alarm acknowledgment confirms an operator has seen an alarm; it silences the signal but doesn't remove the alarm condition.
Example
The operator acknowledges the high-temperature alarm on the HMI; the horn stops, but the alarm stays in the list with steady display until the temperature drops below the limit.
How it applies
- Engineering: Alarm states typically include unacknowledged active, acknowledged active, unacknowledged returned-to-normal and normal; each has its own display (for example flashing vs. steady). Some message classes require acknowledgment, others don't.
- Operation: Acknowledging without understanding is a known failure pattern during floods. Grouped or blanket acknowledgment should be used carefully.
- Documentation: Explain the alarm states and their display in the operating manual, and the difference between acknowledging and resetting. Acknowledgments are typically logged with user and time.
Alarm acknowledgment vs. reset
Acknowledgment confirms awareness. A reset, such as a Reset function after a protective stop, is a deliberate action that re-enables a function once the cause is removed. Operating manuals must not use the two words interchangeably.