You typically use in the Bacnet Niagara Log Export Manager for any “standard history” you wish to export to BACnet as Trend Log object—that is, without the ability for sequence number access from BACnet. Using Discover is not necessary for the history of any component in which you have already added one of the BacnetTrendLogExts—as the Bacnet driver automatically added a BacnetTrendLogDescriptor under the root of the Export Table.
When you click , the top pane shows the histories under the station’s folder, as shown in Figure 88.
As with other manager views featuring online discovery, “Learn Mode” in Bacnet Niagara Log Export Manager has two panes:
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Top (discovered) Local Histories pane—listing all histories in the local station.
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Bottom (database) Exported Objects pane—listing histories currently exported to BACnet. These include both types of log descriptor components—each essentially a pointer to the exposed history, with additional slots that determine how BACnet access/writes are handled. See the next section, Add (and Edit) in Bacnet Niagara Log Export Manager for more details.
When exporting, the manager automatically performs “object ID maintenance” on exported files, ensuring that no duplicate combinations of object type and instance number are created.