Attributes (VF Primary Min Flow Control v61) - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 16.0

Control Status

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

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.

Mode

Desired mode of operation.

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.

Process Dead Time

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

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).

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.

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.

Ramp Rate

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

Setpoint

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