The term 'acknowledged' comes from the Legacy HP OpenView Operations Manager product. When an alarm is 'acknowledged' it is moved to 'history' (a table i the database). Alarms within the 'alarm history table' can be deleted or archived.
Terminating an alarm in NetXMS deletes the alarm from the active alarm browser. We have a requirement to retrieve a list of historical alarms for any and all nodes. If the alarm is 'terminated' within NetXMS it appears that the alarm is permanently removed from NetXMS.
The ability to retrieve historical alarms provides for anomaly analysis. It would be great if a 'Node_up" alarm was recived; acknowledged the "Node_down" alarm, and both were then moved to history; keeping the active alarm browser 'state based'. State based mean that only valid alarms (needing attention) are in the active alarm browser.