The source of a system event is a function block (as with alarms). System events can originate from the same block types as alarms:

  • Analog Input/Output/Value
  • Binary Input/Output/Value
  • Multistate Input/Output/Value
  • BACnet Device Info Object (not in Desigo room automation)

Every block type capable of generating a system event has a clearly defined set of system event triggers.

Event-generating block types


Operating hours counter

The input, output and value objects of the Binary and Multistate types have an inbuilt operating hours counter. A system event is generated when the operating hours limit is exceeded or when the maintenance interval has expired.

BACnet Device Info Object

The BACnet Device Info Object detects the causes of system events which apply to the automation station as a whole. The following causes are detected:

- Change of operating state (start and stop the program)

- Restart after a power-up

- Primary server has found a new backup server on the network

- Backup server has found the primary server