Proxy Ext (bacnet-BacnetBooleanProxyExt)

This proxy extension maps a BACnet Boolean value to a BooleanPoint or a BooleanWritable.
Figure 69.   Bacnet Boolean proxy point properties
Image

This component is under the Points folder in the palette. To add it to a station, drag a BacnetBooleanPoint to the BacnetNetwork > BacnetDevice > Points folder. To view the properties, expand the BacnetBooleanPoint or double-click the Proxy Ext node in the Nav tree.

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

Property Value Description
Facets Opens the Config Facets window
Define the text to display for the Boolean values:
  • trueText is the text to display when output is true
  • falseText is the text to display when output is false.

For example, the facet trueText could display “ON” and the facet falseText “OFF.”

You view Facets on the Slot Sheet and edit them from a component Property Sheet by clicking the >> icon to display the Config Facets window.

Proxy Ext Out, In, and Fallback values
Indicate from where the point’s value originates, including details specific to the parentage of the point’s network and communications (driver).

null indicates that the point is an empty placeholder.

Device Facets additional properties
Determine how values are formatted for display depending on the context and the type of data. Examples include engineering units and decimal precision for numeric types, and descriptive value (state) text for boolean and enum types.

With the exception of proxy points (with possible defined device facets), point facets do not affect how the framework processes the point’s value.

Besides control points, various other components have facets too. For example, many kitControl and schedule components have facets. Details about point facets apply to these components too, unless especially noted.

You access facets by clicking an Edit button or a chevron >>. Both open an Edit Facets window.

Conversion drop-down list (defaults to Default)
Configures the facets to use when converting values from device facets to point facets.
Tuning Policy Name drop-down list (defaults to Default Policy)

Selects a network tuning policy by name. This policy defines stale time and minimum and maximum update times.

During polling, the system uses the tuning policy to evaluate both write requests and the acceptability (freshness) of read requests.

Read Value read-only
Displays the last value read from the device, expressed in device facets.
Write Value read-only (applies to writable types only)
Displays the last value written using device facets.
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.

Property Id number (defaults to 85)
Defines the specific data item being proxied. Often, this is Present Value or Event State. This unique numeric value correlates to and identifies the data item. For example, the number 85 correlates to a present-value property.
 NOTE: Changing this ID on an existing BACnet proxy point can produce undesirable results, especially if the change assigns a different control point type. Instead, make a new proxy point. 
Property Array Index number
Identifies a particular element in an array of stored properties. For example the ObjectList is stored as an array of object identifiers.

This value applies only to an arrayed property, like Priority Array. For example, if the point proxies priority level 7 of a priority array input for a binary output point, this value is 7.

The Present Value property is not an array. For all properties that are not arrays, use an array index of -1.

Data Type read-only
Reports the ASN (Abstract Syntax Notation) data type for a device property. The driver automatically converts values to this appropriate type. For example, an analog input present value is an ASN REAL that can be interpreted by a string point as a character string. ENUMERATED is another example.
Read Status read-only
Indicates if the read status of the proxy extension is: Polled, COV, or Unsubscribed. This status depends on a number of factors. If a read error occurs, other descriptive text may appear instead.
Write Status read-only
Indicates if the proxy extension is read-only or can be written to.

read only indicates the proxy extension cannot be written to.

writable or ok indicates that the proxy extension can be written to.

For writable proxy extensions, this property indicates either that the last write occurred within the effective tuning policy period or, if a write operation failed, it provides descriptive text.

For example, if you create a writable point for a read-only object (say, a NumericWritable for presentValue of an Analog_Input object) and attempt to write from the system, the write status may show: Property:Write Access Denied. If the error is actually a BACnet error, the colon-separated format contains the error class and error code returned by the device.

Out read-only
Displays the current value of the proxy point including facets and status.

The value depends on the type of control point.

Facets define how the value displays, including the value’s number of decimal places, engineering units, or text descriptors for Boolean/enum states. You can edit point facets to poll for additional properties, such as the native statusFlags and/or priorityArray level.

Status reports the current health and validity of the value. Status is specified by a combination of status flags, such as fault, overridden, alarm, and so on. If no status flag is set, status is considered normal and reports {ok}.