Data Manager in the emergency mode

The most important aim in the emergency mode is to maintain a consistent database but, however, the system should still be able to run, although possibly with some restrictions:

  • As long as a system is in emergency mode, new managers (except CTRL, UI or ASCII Manager) must not be started - the message "Emergency Mode (#112)" is issued.

  • All DP messages that require an answer are answered with the message "Emergency Mode ('#112)".

  • All the managers already running continue to run as usual with the only restriction that accesses to _archive configs or historical values is no longer possible.

The project continues to run until the Data Manager is terminated.

Note:

The emergency mode can only be left by restarting the Data Manager, the project is left on. This also applies if the EM was entered into through user input. The config entry checkMemory = 0 prevents the virtual memory from being checked and the entry checkDiskSpace = 0 prevents the available disk space from being checked.

If a project switches to emergency mode, the value archives are not stopped but they also switch to the emergency mode (files are not closed). Thus, a restart of a project in a redundant system in emergency mode, is not automatically triggered.

While the Data Manager runs in emergency mode, alarms may be added or acknowledged but these actions are no longer written to the database. Therefore, alarms that have been acknowledged before may occur again after restarting the Data Manager.

Also during this time, no _archive configs can be viewed anymore in the PARA and configs, data points and data point types cannot be created, modified or deleted.

Monitoring of the status

The disk space and virtual memory are monitored by alert handling for the appropriate data point elements (DPE FreeKB). Message texts in the panel warn the user before the Data manager goes into EM.