User Manual

Alarm management
Alarm example
9
CM110664en_07 137 | 351
State transitions between alarm states
Transition Trigger Action / Event state
TO_OFFNORMAL A new OFFNORMAL alarm condition has been detected. OFFNORMAL
TO_NORMAL1 The current OFFNORMAL alarm condition has disappeared, and there
is no other alarm condition present.
NORMAL
TO_FAULT A new FAULT alarm condition has been detected. FAULT
TO_NORMAL2 The current FAULT alarm condition has disappeared, and there is
currently no other alarm condition.
NORMAL
System events may also occur within each alarm state. These message functions do not affect the alarm
state.
Because FAULT alarms take priority over OFFNORMAL alarms, the state transition from FAULT to
OFFNORMAL only occurs under very special circumstances.
If, while in the OFFNORMAL state, a FAULT alarm condition occurs, there is then a state transition
TO_FAULT (because as stated above, FAULT takes priority over OFFNORMAL).
9.2 Alarm example
What happens in the Desigo system when the V-belt of an extractor fan breaks?
The following figure shows the main information exchanged by the elements concerned, namely:
● Operator
● Ventilation system sensor/actuator (differential pressure monitor, maintenance switch and single-
speed extract air fan)
● PXC program
● Desigo CC plant graphic
● PXM… operator unit
Key
PXC - Programm
RefVal
PrVal
BL
MntnSwi
Zustandsmaschine
disturbed
Notification Class ( =23)
.. ..... High Pro Alarm
........ Extendet Alarm
........ Receiver = DI Name
disturbance
appears
D ?
PrVal
Txt:........................
ACK
RESE
Pop Up
Desigo CC
Auto
ON
OFF
OR
PrVal
Cmd_CNTL
ON
OFF
Auto
Ventilator
Belt
Exhaust Air FAN 1 St.
Txt:........................
ACK
RESE
Pop Up
3
7
1
5
3
4
6
2
1
5
9
3