Attributes (Variable Speed CW with Low Limit v61) - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 16.0

Controller Tool Help

Brand
Johnson Controls
Metasys
Product name
Controller Configuration Tool
Document type
User Guide
Document number
LIT-12011147
Version
16.0
Revision date
2023-10-02
Language
English

The following table describes the attributes used by the Variable Speed CW with Low Limit modules:

Name

Type 1

Description

Default Value

Absolute EWMA Effort

V

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

0.0%

Absolute EWMA Error

V

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

0.0

Display Units: °C, °F

Control Status

V

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

Overridden

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.

True

EWMA Error

V

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

0.0

EWMA Present Value

V

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

0.0%

Limited Max Value   Defines the proportional output when the module is in Limited Max mode. 0%

Low Limit Diff

 

Indicates the low limit setpoint differential.

57.0 l/s, 15.0 gpm

Low Limit Percentage SP

 

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

80%

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.

0.0 l/s, 0.0 gpm

Low Limit Setpoint

 

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

0.0 l/s, 0.0 gpm

Mode

 

Desired mode of operation.

Control

Set Name: Off/Max/Control/Hold/Limited Max

Output Overridden

 

Indicates whether the actual controlled output is overridden.

False

Output Position

 

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

0.0%

Percent Cmd

G, V

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

0.0%

PID Tuning Reset

 

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

Normal

Set Name: PID Tuning Reset

Process ID

 

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

MA-T

Set Name: Process ID

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).

3785 l/s, 1000 gpm

Process Units

 

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

°C, °F

Set Name: Unit

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.

0 °C, 0 °F

Setpoint

 

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

0 °C, 0 °F

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)