User Manual

Alarm management
Alarm routing over the network
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irrespective of when it was connected – displays the current alarm status of
the system.
After making these entries, the temporary alarm receiver, while connected, will
receive all alarm messages from the automation station in accordance with the
routing mechanisms described below.
If an automation station cannot transfer an alarm message to a temporary
alarm receiver (e.g., because it is no longer connected to the network), the
address of the receiver concerned will be removed from the [RecpList]. All
alarm messages destined for that receiver will then be deleted.
The preconfigured alarm receivers are entered in the notification class object:
● In the [DestList] for Desigo PX
● In the [RecpList] for Desigo room automation
Time response in the network
The routing of all alarm and acknowledgement ,messages between the alarm
server and the alarm clients takes place over the BACnet network using special
BACnet services. These are:
● Confirmed Event Notification for all changes in the alarm state of an alarm-
generating object (TO_OFFNORMAL, TO_NORMAL, TO_FAULT), and for
messages via local acknowledgements. Direction: Direction: From alarm
server to alarm client.
● AcknowledgeAlarm for the routing of acknowledgements (including reset)
performed by the user on an alarm client. Direction: From alarm client to
alarm server.
The two services are referred to as Confirmed Services, that is, the receiving
device always confirms the receipt of a service by immediately returning a
SimpleAck message. This tells the transmitting device that its message has
been received by the receiving device. If no SimpleAck message is received, the
transmitting devices tries to send the message again (up to three times).
An alarm is always issued by one (and only one) alarm server. Generally,
however, there will be several alarm clients on the network. To maintain
consistency, all alarm clients must always display the same alarm state. For
this reason, all alarm-related functions must always be routed to all the alarm
clients. The procedure is the same for both temporary and pre-configured alarm
receivers.
The following time-diagrams describe the communications via the network for
the various alarm-related events.
This procedure is carried out for every change in alarm state on an alarm
server: TO_OFFNORMAL, TO_FAULT und TO_NORMAL. The data record
Confirmed Event Notification contains the following information:
● BACnet address of the alarm server
● Object ID of the alarm-generating object
● Time stamp
● Alarm priority
● Initial and final state of the transmitted state transition (this is used to
determine whether the state transition is TO_OFFNORMAL, TO_FAULT or
TO_NORMAL)
● Acknowledgement required [AckReq]: Does the notified state transition
require acknowledgement or not?
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Preconfigured alarm
receivers
Change of alarm state