This section lists the attributes that are common to the system objects.
Attribute Name |
Notes 1 |
BACnet Notes1 |
Initial Value |
Description |
---|---|---|---|---|
Alarm State |
Normal |
Indicates the current alarm state of the object. |
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Archive Date |
Indicates the date of the last successful archive of object instances. The value of this attribute is valid if a valid archive exists and during the archive download process. The value of this attribute is 0xFF at all other times. |
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Authorization Category |
C,W |
W |
General |
Classifies the object by the category of system or equipment that it monitors to aid in the determination of user access privileges and alarm routing. Examples: HVAC, Fire, Security Note: When you are defining a new object, manually select
the Authorization Category from the drop-down list on the Configuration tab. This
extra step is only required if you need to select a category other than General.
For example, if the user is only assigned the HVAC category, manually select HVAC
under the Configuration tab during object definition.
|
Description |
C,N,W |
BNW |
No text |
Contains a user-defined description of the object or, for some integrations, the device description. After the description is defined by the user, the description is not read from the device again. |
Enabled |
True |
Indicates whether the object is set to execute/enabled (True) or not execute/disabled (False). | ||
Item Reference |
C |
Contains a unique reference name for the object that is the full path name of the object through the All Items navigation tree using the unique identifier you specified when you manually created the object. The Item Reference begins with the site and device identifiers (separated by a colon), followed by the identifiers of any parent objects, such as an integration object, field device, or any nested folders, and ends with the identifier of the object itself. You define the identifier of each object as it is created and the system builds the Item Reference automatically. Once the object is defined, the Item Reference cannot be changed directly. But, the Computer Name attribute of a Site Director or device is the object identifier. If you change the Site Director or device Computer Name attribute, the Item Reference then updates to show the new Computer Name. If a device has a domain specified in the Domain Name attribute, the name for the domain appears in the Item Reference after the Computer Name: Computer Name.Domain Name The following characters are not allowed in references: @ ? * # [ ] " ‘ “ ” \ : / < > | $ . , ' _ & Figure 1 shows an example for a field point object in an N2 integration. |
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Name |
C,W |
Item ID |
Contains a freely definable user-friendly Name for the object that is independent of the Item Reference or the location of the object in the physical network. The Name is used as the label in the All Items navigation tree. The Name is shown in alarm reports, the event and audit viewers, and in summaries. The Name does not need to be unique to the site unless the name is used as the BACnet Object Name. When the name is used as the BACnet Object Name, it must be unique among the BACnet Object Names in the device (if it is not a Device object) or unique among the other device objects (if it is a Device object). The following characters cannot be used in an object name: @ ? * # [ ] " ‘ “ ” \ : / < > | $ . , ' _ & The Name defaults to the object identifier you used during manual object creation, but can be edited later. For integrated BACnet objects, the name defaults to the BACnet Object Name in the remote BACnet device. For integrated N1 network objects, the name defaults to the System.Object Name in the Network Communication Module (NCM). Example: ConferenceCenter-Room2-SpaceSetPoint For devices, both the Computer Name and Name attributes default to the object identifier you used during manual object creation. But, do not confuse the Computer Name attribute with the Name attribute. Changing the NAE Name attribute does not impact the object references or network communication with other devices on the site. Changing the Computer Name online breaks any existing references between the NAE object and other objects on the site, and may break the existing network connection to other devices on the network. We do not recommend changing the Computer Name online. If you change the Computer Name attribute in the SCT (right-click the NAE in the navigation tree and select Rename), both the Computer Name and Name attributes are changed to the new name you select. The Item Reference then updates to show the new Computer Name. |
|
Object Count |
Indicates the number of object instances within the device. This count includes objects of any type. | |||
Object Identifier |
C |
B |
Indicates the instance number of the Object Type used in the BACnet Object ID as exposed to a BACnet network. The object ID must be unique within the host device. The object ID of the Device object must be unique within the BACnet network. |
|
Object Name |
B |
Indicates the Object Name as exposed to a BACnet network. This attribute is equivalent to the Item Reference without the site identifier. You cannot edit this attribute, but it changes when the Item Reference attribute updates. In addition, you can change the Object Name attribute by editing the User Name attribute and setting the User Name Is BACnet Obj Name attribute to True. Example: NAE3/N2 Trunk1.AHU4.Supply Temp |
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Object Type |
B |
Indicates the Object Type as displayed in the software and as exposed to a BACnet network. Example: AI (Analog Input) |
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Status |
Normal |
Displays the highest priority Status for the object. The value of the Status attribute displays next to the Default Attribute for Display (typically Present Value) in the header bar of the Display panel. Examples: (in order of priority - supported states depend on Object Type) – Out Of Service: The Out Of Service attribute value is True. – Offline: Communication with the physical hardware has failed. – Unreliable: Reliability attribute is not reliable. – Alarm: Object or alarm extension has an alarm state. – Normal: No abnormal condition for this object detected. – Output Clipped: Present Value is outside the limits of Min Value and Max Value. Status remains Output Clipped until the output changes. |
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User Name Is BACnet Obj Name |
C,W |
C,W |
False |
Controls whether the object’s User Name attribute is also the Object Name attribute. The Object Name attribute is not writable, so the only way to change the Object Name attribute is to edit the User Name attribute and set the User Name Is BACnet Obj Name attribute to True. |
Version |
Displays the version number of the object software code. As the functionality of objects is enhanced, the version numbers are incremented. Example: 3.1 where 3 is the major revision and 1 is a minor revision |