Attributes (VF Primary Min Flow Control v61) - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 15.0

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Johnson Controls
Product name
Controller Configuration Tool
Document type
User Guide
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The following table describes the attributes used by the VF Primary Min Flow Control modules:


Type 1


Default Value

Control Status


Current status of the module. See the PID specification for more information.


Set Name: Control Status

Direct Acting


Signals the action of the PID: True= Direct Acting, False = Reverse Acting. Direct acting control is used in applications where an increase in the process variable causes the controller’s present value to increase. An example of direct acting control is temperature control with a cooling coil. With reverse acting control, an increase in the process variable causes the control present value to decrease. Three examples of reverse acting control are: temperature control with a heating coil, flow rate control, and static pressure control applications.


Limit Active


Enables the Limit Active to operate when set True. If Limit Active is False, the output is set equal to the input.


Limited Max Value


Defines the proportional output when the module is in Limited Max mode.




Desired mode of operation.


Set Name: Off/Max/Control/Hold

Output Overridden


Not implemented at this time; for future use. Indicates whether the controlled output is overridden externally.


Output Position


Not implemented at this time; for future use. Used for bumpless transfer after an output override is released.


Percent Cmd


This is the analog percent output to the control device.


PID Tuning Reset


Causes the PID objects to reset their tuning parameters to the default based on the appropriate Process ID.


Set Name: PID Tuning Reset

Process Dead Time


The time required for the process variable to begin to reflect the results of a step change of the Percent Cmd.

6 Seconds

Process Range


The magnitude of the range that the PID Process Variable traverses as the PID Present Value varies between its minimum and maximum values. For example, when the Process Variable ranges between 60 and 90 degrees due to the PID Present Value varying from its Low Limit to its High Limit, then Process Range is set to 30 (60 - 90).

6.3 l/s, 100 gpm

Process Time Const


The time required for a first-order system to reach 63% of its final magnitude given a 100% step change; it is often represented by the symbol T.

60 Seconds

Process Variable


When Mode is commanded to Control, this is the controlled variable. Therefore, this variable must respond to changes in the output. For example, it can be connected to the Zone Temperature.

6.3 l/s, 100 gpm

Ramp Rate


Analog value that defines the rate of change in Percent Cmd output.

60 per Minute



This is the desired setpoint for the process variable when commanded to Control.

6.3 l/s, 100 gpm



Indicates operating state of the module.


Set Name: Off/Max/Control


1 B - BACnet Exposed Parameter, C - Configuration Mode Only, G - Default Element (Generated State, if applicable), SC - Simulation and Commissioning Modes Only, V - Calculated Value (Outputs)