Bacnet Niagara History Descriptor (ServerNiagaraHistoryDesc)

This component is the server log descriptor that exposes a standard history to BACnet as a trend log object. It supports exported histories based on time and index request for the trend log data. You use the Bacnet Niagara Log Export Manager view of the BACnet Export Table to add, edit, delete, and access these descriptors. Alternatively, you can add one of several BacnetTrendLogExt (specialized history extension) too a point to create another type of log descriptor.

Figure 142. Bacnet history descriptor properties

You use the Bacnet Export Manager view of the Bacnet Export Table to add, edit, delete, and access exported components.

In addition to the common properties (Status and Fault Cause), this component has these properties.

Property	Value	Description
Event Detection Enable	`true` (default) or `false`	Turns detection of an input event on and off for analog, binary and multi-state descriptors. How to find: expand the BACnet network, Local Device > Export Table and discover objects or create a new descriptor, then click the view drop-down list, select `AX Property Sheet`, and expand the descriptor
Bacnet Status Flags	read-only indicator and check boxes	Configures four status flags for BACnet. These options are available to enable detection of specific status conditions. How to find: expand the BACnet network, Local Device > Export Table and discover objects or create a new descriptor, then click the view drop-down list, select `AX Property Sheet`, and expand the descriptor or expand the BACnet network, Local Device > Export Table and double-click an input
Id	read-only	Appears only for a BacnetNiagaraHistoryDescriptor, and reflects the same history Export Ord in the station. How to find: expand the BACnet network, Local Device > Export Table and discover objects or create a new descriptor, then click the view drop-down list, select `AX Property Sheet`, and expand the descriptor
Object ID	drop-down list and number (from 0 to 4194302)	Identifies each device and component by the type of entity (`Object Id`) combined with a unique `Instance Number`. For devices (controllers, instruments, meters, etc.), `Instance Number` must be unique within the BACnet internetwork. For components (points, schedules, analog inputs, files, groups, multi state inputs, etc.), it must be unique within the device.
Object Name	text in the format name.name.name.name (default includes the entire component path in the station using period (“/) delimiters between parent.child levels)	Identifies a BACnet object. This name should be unique within this specific device. When you select an object to add as a proxy point, this is the default name in the station for the BACnet proxy point. Including the path enforces (externally) the BACnet requirement for unique names for all objects in a device. How to find: Appears on all device and component Property Sheets and on the Search for objects by name or id window.
Description	text	Provides additional information, which could include the camera’s geographical location or other unique information. NOTE: After creation (adding) BACnet file descriptors, note that each descriptor also has additional properties accessible in its property sheet, along with those seen in the Add and Edit window. How to find: This property appears on multiple Property Sheets and in multiple windows.

Bacnet Niagara History Descriptor (ServerNiagaraHistoryDesc)

Figure 142. Bacnet history descriptor properties

Related Links