Setting up a point export descriptor

You export point values (Analog Value, Binary Value, Multistate Value) from a server (remote controller) station to a client, such as a Supervisor station so that the client can view the current value of each point, and process historical trends. This is sometimes referred to as “exporting to BACnet” and “exposing objects in the host station.” This procedure sets up export descriptors in the station’s Export Table.

Prerequisites: You are using Workbench connected to a remote host station with points to export. If this point is capable of generating alarms, you configured the AlarmService before exporting point values. If you are exporting large numbers of records, you are ready to set up a folder structure to facilitate export management.

Expand Config > Drivers > BacnetNetwork > Local Device and double-click Export Table.
The Bacnet Export Manager view opens.
To create a folder, click New Folder, give the folder a name and click OK.
Logically organizing multiple BACnet export descriptors into folder containers saves time. For example, one or more folders may represent a driver network, and another folder may contain schedules. Each export folder provides the same set of export manager views as the Export Table.
The station exposes export folders to BACnet as Structured View Objects, allowing a hierarchical organization of BACnet objects.
To create a descriptor, click New.
The New window opens.
Select the type of descriptor to add using the Type to Add drop-down list and Number to Add, then click OK.
Type to Add is the type of point to configure for export. By increasing the Number to Add value you can create multiple instances of this point type in this single step.

The New point window with properties opens.
Use the batch search and replace feature () to identify each point by its Object Name or Description.
To configure the descriptor to export a group of points at once, select them all in this window, enter the Inst Num for the first one.
The driver assigns each descriptor successive instance numbers as available.
Configure the other properties and click OK.

The manager automatically performs object ID maintenance on exported components, which ensures that the driver creates no duplicate combinations of object type and instance number. It also adds to each exported object an OutOfServiceExt.

Any exported points or components that contain an alarm extension are automatically exposed to BACnet with properties related to alarming available. For example, if you export a NumericPoint with an OutOfRangeAlarmExt, its exposed BACnet object (say, Analog Value) contains properties High Limit, Low Limit, Deadband, and so on.

NOTE: Before deleting any source (exported) component from the station, use the Bacnet Export Manager to delete its corresponding BACnet export descriptor. Otherwise, the export descriptor may remain orphaned in the Export Table, showing Invalid Ord! in the Target Name and Value columns. If this occurs, delete the orphaned export descriptors manually.

Setting up a point export descriptor

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