Bacnet virtual points can show real-time values in Px views. Starting in AX-3.3, this includes an available right-click “set” action, as well as the Niagara poll status (ok, stale, down) of the polled property.
A BacnetVirtualGateway cannot have its “own” Px view, but you can use its child virtual components in Px views for other components, for example on the
Bacnet Device itself, or its Points extension, and so on.
The only persisted (permanent) record any Bacnet virtual point is its ord in the Px binding to it, which uses a “Bacnet virtual ord syntax” that includes the BacnetVirtualGateway within the ord. This ord is automatically resolved when you drag a Bacnet virtual component onto the Px page, and make your selection in the popup Px “Make Widget” dialog.
For complete details on Px view and widget editing, see “About Px Editor” in the User Guide.
The next two sections explain Px usage of Bacnet virtuals (AX-3.3 and later) and Px usage of Bacnet virtuals in AX-3.2.
Starting in AX-3.3, you can drag a BacnetVirtualProperty into a Px view for a “Make Widget” dialog, as shown in the example in Figure 59.
Often you may wish to include the “presentValue” property, as shown here. In the Make Widget dialog, you can select either “Bound label” (as shown) or “Workbench view” for the “Bacnet Virtual Property View.” If using a bound label, the accompanying display name label (if that option was selected) can be edited to another text string, as shown in Figure 60.
At the time of this document, every BacnetVirtualProperty provides an action to write (“set” is default name), which may be useful in some scenarios. Figure 61 shows an example action being invoked.
By default, in the case of a write to the “presentValue” property of a BACnet object with a priority_array (such as an Analog Output or Binary Output), the Niagara write is issued at priority level 16. You can specify another priority level by editing the ord used in the Px binding (to the Bacnet virtual component). See Bacnet virtual ord syntax for related details.Bacnet virtual ord syntax
Currently, the “set” dialog for a BacnetVirtualProperty for present_value provides two fields (Figure 62).
The two fields in the set action dialog apply as follows:
-
Data type drop-down list (Real, Binary, Integer, NULL), with the applicable type (among the first three) preselected. The only valid change is to NULL, to clear (auto) the priority_array at that level.
-
Value to write (numeric real, binary state drop-down, integer), with the current value initially shown. Currently if a binary object, the drop-down values are expressed as either “active” or “inactive”.
In an AX-3.2 station, you can drag a BacnetVirtualComponent in the Px view, and then select “Properties” in the popup Make Widget dialog to select which property, as shown in the example in Figure 63.
Often the “presentValue” property will be selected, as shown above. The accompanying display name label (if that option was selected) can be edited to another text string, if desired, as shown in Figure 64.
Unlike with Bacnet virtual points in AX-3.3 and later, there is no included polling status nor any available right-click actions, such as “set”.