Alarm System

The Karabo alarm system is separate from the distributed logging system. It works by raising alarm conditions which are displayed in the GUI, can be queried from the CLI and are maintained by a centralized alarm service.

In Karabo there are four alarm states, signified by color, symbol and level-number. They are summarized in the following table:

Alarm and warning conditions in Karabo and their graphical representation for to-be-acknowledged alarms (left symbol) and non-acknowledgeable alarms (right symbol)

Alarm Conditions	Symbol	Comment
INTERLOCK		The property triggered an interlock
CRITICAL		The property is in its critical value range
WARNING		The property is in a value range where it should be monitored
NONE	None	The property is in its normal value range

Alarm conditions are usually indicated on a per-property basis and set either through automatic evaluation of the bounds specified for a property or through explicit calls.

Additionally, each device has a property globalAlarmCondition, defined in the device base class. It is automatically set to the most significant property alarm state on the device, where INTERLOCK is more significant than CRITICAL is more significant than WARNING is more significant than NONE.

This should be reserved for when an alarm cannot be attributed to having resulted from device properties. In all cases you should provide a short description of why the alarm condition was triggered. Like property alarms, interlock and critical conditions must be acknowledged. Acknowledgement of warnings can be controlled using the acknowledge parameter, which defaults to false.

Warning

Alarms should always be indicated on the property which triggered the alarm if it is known.

Alarm conditions are independent of device state. A device may be working perfectly, but its read-back values indicate that hardware is behaving abnormally. For example, a valve indicates a quick rise in pressure which is abnormal, the valve and valve device are working normally but the value indicates an alarm condition.

Acknowledging Alarms

Alarms may be acknowledge in two ways: by using The Alarm Service Device as described below.

The Alarm Service Device

The alarm service device is the central collection point for all alarms in a Karabo installation. It receives alarms from all other devices and allows acknowledgement of these and filtering by alarm condition and type, as well as instance id and device class. Mainly it is to be interacted with from the GUI as described in gui_alarm_service.