BACnet object

A BACnet system is object-oriented, which means that all information in the system is represented in terms of objects. All BACnet devices have at least one BACnet object - the device object, which purpose is to represent the device it self. Other objects are of different types and can represent sensors, actuators, trend-logs and other.

All BACnet objects contain some required BACnet properties that are determined by the object's type. These are automatically created under the object's creation.

Database ID: This is the identifier that the BACnet object has been automatically assigned by the database on the DINGO device. It can be useful in advanced troubleshooting situations. If the identifier is negative, it means that the BACnet object has not yet been saved to the DINGO device.

Object name: This is the name of the object.

Object type name: This is the name of the type of the object.

Object instance nr.: This is the instance number for the object The user has to be careful to avoid conflicts by choosing an instance number that is unique within the BACnet device and object-type.

COV enabled: This property determines if the BACnet object is enabled for change of value (COV) reporting.

Enabled: This property determines if the BACnet object is enabled. If it is not then it will not be seen on the network. BACnet objects of type Device are always enabled. When changing the enable-property of the object, a dialog will ask if you would want to enable/disable dependant trend-logs and peripheral dependencies. This means that trend-logs that are trending from the object, will also be enabled/disabled. However trend-logs on remote devices will not be effected. Peripheral ports that are used by the object will also be enabled/disabled. Any configuration of the LoRaWAN server or other services will not be effected.

Every BACnet object has three BACnet properites: object-identifier, object-name and object-type. Certain object types have then, specific additional required properties. These are automatically added when the object is created, and can not be removed.

The object types have also specific optional properties available, that can be added or removed. There can also be specific proprietary (vendor specific) properties available for the object type, that are not described by the BACnet standard.

The BACnet properties of the BACnet object are divided into two data-grids: Properties in object and Available optional/proprietary properties.

The data-grid shows what properties are currently within the BACnet object.

Name: This is the name of the property.

Datatype: This is the datatype of the property.

Database value (raw): This is the value of the property as it is stored in the database.

BACnet server (raw): If the BACnet server is running and the BACnet object is enabled within the server, then this property will show the value as it is currently within the BACnet server.

Example: For example if the property is bound to a real-life temperature sensor, then the value from the sensor would be displayed here.

Edit: This a hyper-link button that will open a new window where the property value can be edited.

Type: This is the type of the property. The options are required, optional and proprietary. Proprietary means that the property is not described by the BACnet standard, but invented by Go-IoT.

Note: Only optional and proprietary properties can be removed from the object. The user will select the property in the data-grid and click the Remove button to remove the property.

There are optional, and possible proprietary properties, that can be added to the BACnet object. What properties that are available depends on the object-type. To add a property the user will select the available property from the data-grid and click the Add button, to add it to the object.

Name: This is the name of the property.

Datatype: This is the datatype of the property.

Above the data-grid is a toolbar with options regarding the BACnet server. These options only function if the BACnet server is running and the BACnet object is enabled within the server.

Clicking Load values will go through all properties in the object and load the current values for them, from the BACnet server.

Clicking Subscribe will make a COV subscription to the value of the "Present value" property of the object. If the value changes in the BACnet server, it will be pushed into the DINGO-Manager. A graph will be displayed showing the values as they change.

Clicking Chart will open a new window with all the values received from the COV subscription.

  • Click the Last 20 button, to read the last 20 records from trend-log.

  • Click the Record viewer button, to customize a search for records in the trend-log.

    The boolean values of log-status in the records, stand for:

    • LOG_DISABLED: This flag is changed whenever the collection of log records by the trend-log object is enabled or disabled.
    • BUFFER_PURGED: This flag is set to true whenever the buffer is cleared by writing zero to the record-count property or by a change to the log-device-object-property property.
    • LOG_INTERRUPTED: This flag indicates that the collection of log records by the trend-log object was interrupted by a power failure, device reset, object reconfiguration or other such disruption, such that samples prior to this log record might have been missed.

    The boolean values of status-flags in the records, stand for:

    • IN_ALARM: False if the event-state property has a value of normal, otherwise true.
    • FAULT: True if the reliability property is present and does not have a value of no-fault-detected, otherwise false.
    • OVERRIDDEN: True if the point has been overridden by some mechanism local to the BACnet device. In this context "overridden" is taken to mean that the present-value and reliability properties are no longer tracking changes to the physical input. Otherwise, the value is false.
    • OUT_OF_SERVICE: True if the out-of-service property has a value of true, otherwise false.