5.4.1.1 Event messages

Each message stored in the event log contains a time stamp, the message source, a message text and a priority or severity value. The event priority tells about the importance of a event message.

• Informational messages are of the lowest priority. Events which do not signal a fault or warning (like user logins) are logged as informational messages. Also messages which indicate the end of a fault or warning state are marked informational.
• Warning messages (medium priority) signal the warning state of a device or software component.
• Fault Fault messages (medium priority) signal the fault state of a device or software component.
• Alarm messages have the highest priority. They signal a severe fault which needs to be repaired immediately or that prevents the operation of the faulty component.

With a M&C system, the event log is stored at the M&C computer. The user interface software provides a Event Report Window which lets the operator query the event database and a Live Event Log Window which displays the recent events in a scrolling list.

The event database is limited in size. It implements a circular buffer which automatically purges all events older than a configurable limit. The factory setting for event log depth is 365 days. The system administrator may change this by modifying a configuration file EDB.properties