Attributes (Variable Speed CW with Low Limit v61) - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 13.1

Absolute EWMA Effort

V

Provides an EWMA based on the absolute value of (Current Present Value - Last Present Value). The PID computes this value.

Absolute EWMA Error

V

Provides an EWMA based on the absolute value of (Setpoint - Process Variable). The PID computes this value.

Control Status

V

Current status of the module. See the PID 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.

EWMA Error

V

Provides an EWMA based on the difference of (Setpoint - Process Variable). The PID computes this value.

EWMA Present Value

V

Provides an EWMA of the Present Value. The PID computes this value.

Low Limit Diff

Indicates the low limit setpoint differential.

Low Limit Percentage SP

Indicates the value to which the process variable is compared, allowing the module to enter the low limit mode.

Low Limit 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 CW Flow.

Low Limit Setpoint

Contains the desired setpoint for the low limit process variable to be controlled to when the mode is Control.

Mode

Desired mode of operation.

Output Overridden

Indicates whether the actual controlled output is overridden.

Output Position

Provides the current Present Value of the output driven by the controller.

Percent Cmd

G, V

This is the analog percent output that controls the single actuator that provides cooling or heating.

PID Tuning Reset

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

Process ID

Specifies the process being controlled. See the PID Pre-Processor for details.

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 Units

Specifies the units for the PID. See the PID Pre-Processor for details.

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 CW Differential Pressure.