Table 1 describes the Accumulator 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. Unless otherwise stated, the attributes listed in this table appear in the Details dialog box (for example, the Present Value appears in the Control View below the module name in Simulation and Commissioning modes).
Name |
Type |
Mode |
Description |
---|---|---|---|
Debounce |
Input |
All Modes |
Indicates the length of time that the hardware input must remain in a state for the connected object to detect that a change has occurred. The hardware contact may bounce, producing extra input pulses. You can use the Debounce attribute to eliminate these nuisance input pulses. Contact fluctuations are ignored and, thus, filtered during this time period.
Note: Debounce is an attribute of only an MS/TP Accumulator (Counter Input).
|
Description |
Input |
All Modes |
Indicates the description provided for the object. |
Device Type |
Input |
All Modes |
Describes the physical network device to which the object is connected. |
Limit Monitoring Interval |
Input |
Configuration |
Specifies the monitoring period in seconds for determining the Pulse Rate. The Pulse Rate is the number of pulses received during the previous Limit Monitoring Interval period. |
Max Value |
Input |
All Modes |
Specifies the maximum amount for Present Value (appears as O1). |
Name |
Input |
All Modes |
Indicates the name of the object. |
Object Identifier |
Input |
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 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. |
Offline |
Input |
Commissioning |
Indicates if the object is currently communicating with the network device. This attribute is visible in an SAB device. |
Out of Service |
Input |
Simulation Commissioning |
Indicates whether the object is currently connected to the hardware or offline (out of service). This attribute is visible in an SAB device. |
Periodic Update |
Input |
All Modes |
Specifies the amount of time between evaluation of updates to Present Value (appears as O1), Reliability, and Status. Default Value: 60 seconds Range: 1 - 10,000 seconds |
Prescale |
Input |
Configuration |
Indicates the coefficients used to convert the accumulated pulses into the Present Value. This attribute uses moduloDivide integer division (where 5/2 is 2 with a remainder of 1; the integer division is carefully implemented to avoid round-off errors by carrying the remainders forward in the calculation). The algorithm used is Present Value = (prescale.multiplier x accumulated-pulses*)/prescale.moduloDivide. * The accumulated-pulses value in this calculation includes the remainder from the moduloDivide integer division calculation. |
Present Value (Appears as O1) |
Input |
Simulation Commissioning |
Indicates the prescaled pulse count. The raw pulse count is adjusted by the Prescale calculation to arrive at the Present Value. Changes in Present Value generate a COV when the Periodic Update expires. Present Value is saved once per day, and returns to the last saved value during a restart. For controllers with fast persistence, present value may be saved up to once per second. Note: The Present Value is saved and does not return to the default value after a transfer to the computer and a transfer to the device with the tool.
This attribute is a calculated value (Output). |
Reliability |
Input |
Simulation Commissioning |
Provides the following values to indicate whether or not the Present Value (appears as O1) is reliable:
Set Name: Reliability This attribute is a calculated value (Output). |
Status |
Input |
Simulation Commissioning |
Reflects the status of the object based on the Reliabilityattribute and the status of any commands. Possible values for Accumulator objects are:
This attribute is a calculated value (Output). |
Units |
Input |
All Modes |
Specifies the units of measure for Present Value (appears as O1). |
Use Default if Not Reliable |
Input |
All Modes |
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. |
Value Set | Input | Commissioning |
Use to reset the Present Value. The Present Value attribute gains its value from the value written to the Value Set attribute. |