Bacnet File Descriptor (ServerFileDesc)

This component exposes a file under the station’s folder as a BACnet file object. You use the Bacnet File Export Manager view of the Bacnet Export Table to add, edit, delete, and access exported files.

All files are accessed using the STREAM_ACCESS method.

Figure 136.   Bacnet File Descriptor properties
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One way to view these properties after dragging this descriptor to the BacnetNetwork > Local Device > Export Table, is to double-click the ServerFileDesc node in the Nav tree.

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

Property Value Description
File Ord text Configures the file location.
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.

For components, this name includes the entire component path under the station’s Config using period (.) delimiters between parent.child levels. This enforces (externally) the BACnet requirement for unique names for all objects in a device.

For a proxy point, this is the default name in the station.

You can shorten or edit Object Name, however, each Object Name must be unique among all server descriptors under the Export Table.

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.  
File Type text string (defaults to blank) Specifies the BACnet property, as a text string intended to identify the use of this file. While the default value is blank, the actual exported BACnet File object contains some default values, such as text/plain or application/zip.
Archive Time timestamp Compares Timestamp against the actual file timestamp in order to set the BACnet property Archive (True if Archive Time < file timestamp, or False if Archive Time > file timestamp).
File Access Method read-only Reports the BACnet property that indicates the type of file access supported: Stream Access only.
 NOTE: Additional properties in the exported File object exist, even though they are not visible in the Bacnet File Descriptor property sheet. These properties include:
  • File Size (integer, in bytes)
  • Modification Date (actual file timestamp)
  • Archive (True or False, see Archive Time property above)
  • Read Only (True or False, as determined by the local Java file system)