BacnetTrendLogDescriptor is the server descriptor that exposes a Niagara history created with a BacnetTrendLogExt as a BACnet Trend Log object. These descriptors are automatically created in the root of the BacnetExportTable when you copy one of the various BacnetTrendLogExt extensions into a component. For related details, see BacnetTrendLogExt.

Unlike a history exported with a BacnetNiagaraHistoryDescriptor (created by a “standard” Niagara history extension), a history exported by a BacnetTrendLogDescriptor appears as a fully BACnet-compliant Trend Log object. This means that it supports “by sequence number” requests in addition to “by time” requests from external BACnet devices.