Defining Alarms

For alarm management in CODESYS the following definitions apply to an alarm. An alarm definition consists in principle of

• a general description (ID, message text, etc.)
• a description of the cause of the alarm (expression to be monitored, limits, min. pending time, etc.)
• a description of the effects of the alarm (actions, display properties, confirmation method etc.).

Acknowledgement of alarms: the main reason for the use of alarms is to inform the user about an alarm situation. In order to ensure that the user has taken notice of the information, CODESYS provides you with various actions that you define in the alarm class. The user must acknowledge the alarm in order to delete it from the alarm list. The special types of alarm acknowledgment are described in the status diagrams as status transitions.

Alarm event: an alarm event is linked to an alarm condition. While an alarm condition can exist over a lengthy period, the alarm event describes the momentary occurrence of a change, for example the change from the normal state to the alarm state. In the CODESYS alarm configuration the same names (Active, ACK, Inactive) are used for the three types of events and the associated alarm status.

The following features are supported in CODESYS:

• Deactivation of the alarm generation for simple alarms as well as for alarm groups
• Selection of the alarms that are to be displayed, by definition of alarm groups and priorities
• Display of all alarm events in an alarm table
• Visualization elements Alarm table and Alarm banner in the CODESYS visualization