Table 1 describes the Analog Value object attributes. These attributes are displayed in alphabetical order. See Object Attributes in the Input and Output Objects section for descriptions of the data provided in this table.
Name |
Type |
Mode |
Description |
---|---|---|---|
Application COV |
Input |
All Modes |
Provides a change-of-value function for the application. The Application COV is set to a non-zero value for setpoint inputs only (Network Sensor inputs excluded). For all other input types, the value is set to zero. This attribute is used for inputs that change frequently, causing the application to run, which may increase COV messages on the MS/TP Field Bus. |
BACnet Exposed |
Network Input Network Output |
All Modes |
Use to expose the object to BACnet systems. The BACnet exposed object is a viewable object through the Supervisory Controller. |
COV Increment |
Input Output Network Output |
Configuration Commissioning |
Indicates the minimum change in Present Value (appears as O1) that triggers a new COV message. Range: 0–100 |
Default Value |
Network Input Network Output |
All Modes |
Use to specify the Present Value if no source is connected or if the connected source is never reliable. |
Description |
Input Output |
All Modes |
Indicates the description provided for the object. |
Destination References |
Output |
Simulation Commissioning |
Indicates the array of attribute references for the destinations. All references must be from a single object. |
Display Precision |
All Types |
Configuration Commissioning |
Indicates the point at which value attributes are rounded for display (and how many numbers following the decimal point appear). Set Name: Display Precision |
Error Status |
Network Input Network Output |
Configuration Commissioning |
Status of the last communication that occurred with an input or output reference. Common errors include:
|
Failsoft |
Network Input Network Output |
All Modes |
Indicates how the Network Input or Network Output behaves when the connected source, such as a supervisory command or peer reference, is not Reliable. If the source is not Reliable, the element uses either the default value for the current value (if Failsoft is true) or the Last Reliable Value (if Failsoft is false). For a Network Input, the source is considered unreliable whenever the priority array of the Present Value is empty. |
In Test |
Network Input Network Output |
Simulation Commissioning |
Displays a Boolean value that is True if you manually set the Current Value for test purposes. This attribute is a calculated value (Output). |
Max Value |
Input Output |
Configuration Commissioning |
Represents the upper limit for Present Value (appears as O1) when it is used to calculate output. If Present Value is higher than the value specified in this attribute, Present Value assumes the value of Max Value.
Note: This attribute does not affect the value of the Present Value attribute, only the impact Present Value has on Output calculation.
Max Value must be greater than Min Value. This attribute resets to the default value if you edit the Units attribute. Units: See Units. |
Min Change to Send |
Output |
All Modes |
Indicates the array of floating values (each value corresponding to a single Input) to specify the minimum change in the Input that is sent to the destination. This attribute is only applicable when the Input is of floating-point data type. The change is evaluated by comparing the current value of the Input to the value the last time a message was sent to the destination. |
Min Value |
Input Output |
Configuration Commissioning |
Represents the lower limit for Present Value (appears as O1) when it is used to calculate output. If Present Value is lower than the value specified in this attribute, Present Value assumes the value of Min Value.
Note: This attribute does not affect the value of the Present Value attribute, only the impact Present Value has on Output calculation.
Min Value must be less than the Max Value.This attribute resets to the default value if you edit the Units attribute. Units: See Units. |
Name |
All Types |
All Modes |
Object name. |
Object Identifier |
All Types |
All Modes |
Indicates the instance number of the Object Type as exposed to the network. The Object Identifier must be unique within the host device. The Object Identifier is created after defining hardware in the Hardware Definition Wizard accessible from the Define Hardware button or Operations menu option. The Object Identifier consists of the BACnet Class ID and the object’s Instance Number separated by a colon. For example, an Object Identifier of AV.10026 has a BACnet Class ID of AV and an Instance Number of 10026. |
Out of Service |
Input Output |
Commissioning |
Indicates whether the object is currently connected to the hardware or offline (out of service). This attribute is visible in an SAB device. This attribute is a calculated value (Output). |
Peer Reference |
Network Input Network Output |
Configuration Commissioning |
Contains the elements needed to use peer-to-peer communication. These elements are:
|
Present Value (Appears as O1) |
All Types |
Simulation Commissioning |
Indicates the current value (with the highest priority) being sent to this object. Present Value is used to calculate the output.
Note: During this calculation, Present Value is restricted between Min Value and Max Value; however, the value represented in the Present Value attribute is not restricted.
Units: See Units. This attribute is a Default Element and is a calculated value (Output). |
Reliability |
All Types |
Simulation Commissioning |
Provides the following values to indicate whether or not the Present Value (Appears as O1) is reliable:
This attribute is a calculated value (Output). |
Relinquish Default |
Input Output |
Configuration Commissioning |
Contains the default value for Present Value (Appears as O1) when all priorities are released. The Present Value is sent to the value in Relinquish Default only at startup or when the last priority value is released. Present Value does not update if you change Relinquish Default. Units: See Units. |
Restore Command Priority |
All Types |
All Modes |
Restores the commands you select in the case of a power failure. For more information about command priorities, see Command Priority Levels. The following list displays the command priorities you can select.
|
Source References |
Input |
Simulation Commissioning |
Indicates the array of attribute references for the sources. All references must be from a single object. |
Status |
All Types |
Simulation Commissioning |
Reflects the status of the object based on the Reliability attribute and the status of any commands. Possible values for Analog Value objects are:
This attribute is a calculated value (Output). |
Units |
All Types |
Configuration Mode for All Types Commissioning Mode for Input and Output Types |
Indicates the units of measurement for Present Value (Appears as O1), Min Value, and Max Value. This attribute resets to the default value if you edit the Setup attribute. Set Name: Unit |
Use COV Min Send Time |
Input Output |
Configuration Commissioning |
Configures the object to send COV messages on a periodic basis instead of on every change of value that exceeds the COV Increment. This attribute is typically set to True for objects with values that fluctuate greatly, such as air pressure, to decrease the number of COV messages. The change of value still must exceed the COV Increment to be reported. Note: If you have more than 100 objects, set this value to False.
The Min Send Time value is set at the supervisory controller on the Device object, and has a default of 15 seconds. |
Use Default if Not Reliable |
Input Output |
All Modes |
For Inputs: Specifies the behavior when the Source is not reliable. If True, the Output is set to its Default Value whenever its Source is not reliable and its Reliability is marked as Reliable. If False, the Output maintains its last reliable value and its Reliability reflects the reason that the source is not reliable. For Outputs: Specifies the behavior when the Input is not reliable. If True, the destination is sent the Input’s Default Value whenever the Input is not reliable and its Reliability is marked as Reliable. If False, the destination is not updated and keeps its last reliable value. |