5. Alarms
Acknowledging alarms
When designing pages, it is possible to define whether the alarm page should be systematically acknowledged or not. These 2 types of alarms are managed in the following way:
Alarms which must be acknowledged
An alarm which must be acknowledged remains in the list of alarms until it is acknowledged by the operator, even if the cause of the fault is no longer present (the alarm bit is back to 0). Its status is then OFF.
Advantage: transient faults are isolated (instability of a discrete sensor for example).
Alarms with optional acknowledgment
An optional acknowledgment alarm disappears from the list as soon as the cause of the fault is no longer present (the alarm bit is back to 0), whether the alarm has been acknowledged or not.
Advantage: Do not monopolize the screen with faults display that are considered minor for the application.
Obligatory and optional ACK
PLC bit state (dialogue table - Alarms bits)
1
0
ACK
1
0
Optional ACK
ON ACK
Disappear
ON
Disappear
Obligatory ACK
ON ACK
Disappear
ONOFF
Disappear
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Graphic Magelis
