User Manual

Alar
m management
Alarm sources
9
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● Event Enrollment
● Command Control object
2
● Power Control object
2
● Schedulers (Analog / Binary / Multistate Scheduler object)
2
● AlarmCollection object
● Discipline I/O
1, 2
● Trend Log / Trend Log Multiple
● Group
1, 2
● Device Info object, which models the properties of an automation station as
a complete entity
● Loop object
Key
1
Discipline I/Os, Groups, Time Scheduler and Trend Log Multiple support only system alarms,
that is, only alarms of the FAULT type. Both function blocks can transmit more than one
system alarm. The parameters [Rlb] and [MsgTxt] provide detailed information about the
cause of the most recent alarm message. The messages are transmitted in the order in
which they occur, irrespective of the importance of the alarm.
2
These function blocks only exist in Desigo PX.
Only these alarm sources incorporate Intrinsic Reporting, and can thus
generate their own alarms. If any other value of a function block needs to be
monitored for an alarm (e.g., the control signal for a controller block), an Event
Enrollment object must be added.
Alarm-generating function blocks include a range of interface variables which
can be set as parameters to determine the alarm response (Input Property) or
to supply the relevant alarm state information (Output Property). These
interface variables are described further below. Some of the interface variables
are common to all alarm-generating block types, while others are specific to
certain types of alarm-generating blocks.
Alarm state machine in an alarm-generating function block
The response in the event of an alarm is modeled by an alarm state machine.
Each alarm-generating block incorporates an alarm state machine of this type.
The alarm-related interface variables can therefore be used to define the
response of this state machine, to simulate state transitions, or to represent the
current status of the state machine itself.
The alarm state machine can assume one of three basic states (event states
[EvtSta]):
● NORMAL: There is no alarm condition present
● OFFNORMAL: Alarm caused by an OFFNORMAL condition
● FAULT: Alarm caused by a FAULT condition
Alarm state machine
Alarm state event states