Issue
Using a Lon Binding in EcoStruxure Building Operation
Product Line
EcoStruxure Building Operation
Environment
- Building Operation Enterprise Server
- Building Operation Automation Server
- Building Operation Automation Server Premium
Cause
Binding LON objects to LON objects using the SmartStruxure Variable Connector can cause increase traffic on the LON FT-10 network.
Resolution
To correctly Bind the LON objects:
- Edit this bindings of the node object, (not the SNVT object)
- Use the binding Browser to navigate to the appropriate node/SNVT to bind to
- Drag and drop the object to create the bind
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When you are finished you will see a Hexagon button, which will allow you to edit the Lon Binding Properties. This is the indicator that you are using a LON binding and not a Variable Connector object, which would be represented by a gear and pencil icon.
- Click the Hexagon to edit the Lon Binding properties
- Do not use the default of Acknowledged Profile. Unless the device has a specific reason not to, the best option is to use Unacknowledged Profile. Please see below for the explanations of the LON Message ServiceTypes.
Message Service Type
You can specify one of the following message service types for each connection description. The message service types vary in reliability and resources consumed.
• Acknowledged - means that the sending device expects to receive confirmation from the receiving device or devices that a network variable update was delivered. The sending application is notified when an update fails, but it is up to the developer of the sending device to handle the notification in the device application. While acknowledged service is very reliable, it can create excessive message traffic, especially for large fan-out or polled fan-in connections. When acknowledged messaging is used, every receiving device has to return an acknowledgment. Acknowledged messaging can be used with up to 63 receiving devices, but an acknowledged message to 63 devices generates at least 63 acknowledgements—more if any retries are required due to lost acknowledgements.
• Repeated - means that the sending device sends out a series of network variable updates, but does not expect any confirmation from the receiving device. Repeated service with three repeats has a 99.999% success rate in delivering messages. Repeated service provides the same probability of message delivery as acknowledged messaging with the same number of retries, with significantly lower network overhead for large multicast fan-out connections. For example, a repeated message with three retries to 64 devices generates four packets on the network, whereas an acknowledged message requires at least 64 packets
• Unacknowledged - means that the sending device sends out the network variable update only once and does not expect any confirmation from the receiving device. This message service type consumes the least amount of resources, but is the least reliable.
