Niagara 4.9 introduced security history. Similar to audit history, security history contains only security-related events, such as log-ins and —outs (authentication) and changes to security-related properties, such as changes to the properties that enable and disable secure communication.

The Security History Service provides the same properties as the standard History Service provides. You configure both sets of properties using the AuditHistoryService.

The station stores security-related property changes in both the security history and audit history logs. It stores authentication events only in a security history. This prevents frequent connection events from flooding the audit history.