Attributes (Damper Control [VAV Supply]) - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 15.0

Controller Tool Help

Brand
Johnson Controls
Metasys
Product name
Controller Configuration Tool
Document type
User Guide
Document number
LIT-12011147
Version
15.0
Revision date
2022-11-18
Language
English

The following table describes the attributes used by the Damper Control (VAV Supply) modules.

Table 1. Damper Control (VAV Supply) Attributes

Name

Type 1

Description

Default Value

Auxiliary Flow 1

 

Contains the measured auxiliary flow. The reliability of this input is monitored. The flow estimate parameter updates only when in control and this variable is reliable.

0 l/s, 0 cfm

Auxiliary Flow 2

 

Measured auxiliary flow. The reliability of this input is monitored. The flow estimate parameter updates only when in control and this variable is reliable.

0 l/s, 0 cfm

Auxiliary Stroke Time 1

 

Time (in seconds) that it takes the auxiliary actuator to go from fully closed to fully open or from fully open to fully closed. Should these values be different, the average value is used. This is employed in dual duct and supply/exhaust control applications to keep actuator adjustments within the speed of the slowest actuator.

0 Seconds

Auxiliary Stroke Time 2

 

Time (in seconds) that it takes the auxiliary actuator to go from fully closed to fully open or from fully open to fully closed. Should these values be different, the average value is used. This is employed in dual duct and supply/exhaust control applications to keep actuator adjustments within the speed of the slowest actuator.

0 Seconds

Box Flow Test Position

 

Desired damper position when mode is set to Box Flow Test.

0.0%

CDD-OUTSTATE, HDD-OUTSTATE, or SAD-OUTSTATE (State)

G, V

Current operational state of the output controller.

Set Name: VAV Flow Control State

CDFLOW-ABSEFFORT, CDDFLOW-ABSEFFORT HDFLOW-ABSEFFORT, HDDFLOW-ABSEFFORT, or SAFLOW-ABSEFFORT (Supply Damper Absolute EWMA Effort)

 

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

0.0

Display Units: %

CDFLOW-ABSERROR, CDDFLOW-ABSERROR HDFLOW-ABSERROR, HDDFLOW-ABSERROR, or SAFLOW-ABSERROR (Supply Damper Absolute EWMA Error)

 

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

0.0

Display Units: l/s, cfm

CDFLOW-ERROR, CDDFLOW-ERROR HDFLOW-ERROR, HDDFLOW-ERROR, or SAFLOW-ERROR (Supply Damper EWMA Error)

 

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

0.0

Display Units: l/s, cfm

CDFLOW-EWMA, CDDFLOW-EWMA HDFLOW-EWMA, HDDFLOW-EWMA, or SAFLOW-EWMA (Supply Damper EWMA Present Value)

 

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

0.0

Display Units: %

CDFLOW-SP, HDFLOW-SP, or SAFLOW-SP (Flow Setpoint)

 

Specifies that if the mode is set to Control, this is the desired setpoint to which the Flow is controlled.

0 l/s, 0 cfm

Control Status

V

Current saturation status of the controller.

Set Name: Control Status

Damper Percent Cmd

V

Contains the analog percent output on a scale of 0% to 100%. This value typically is connected to either a PAO or an AO.

Display Units: %

Failsoft Value

 

Desired damper position when in Failsoft mode.

0.0%

Flow

 

Measured flow. When the mode is set to Control, this is the flow that is directly controlled and therefore must respond to changes in the output.

0 l/s, 0 cfm

Minimum Pulse Width

V

Contains the minimum pulse width used by the PVDC block.

Display Units: Seconds

Mode

 

Contains the mode requested by State Selection.

Close

Set Name: VAV Flow Control Mode

PD Max Position

 

Maximum position under unreliable control. Under unreliable flow conditions, flow setpoints are linearly converted into a damper position between this value and 0%.

80.0%

Rated Box Flow

 

Contains the rated flow of the box under nominal conditions. For most control purposes and under most reasonable design conditions, this can be set to the desired maximum box flow. Should the rated flow be larger than the desired maximum box flow by more than 25% unstable control may result. Correct this by setting this value to the actual rated box flow.

500 l/s, 1000 cfm

Stroke Time

 

Time (in seconds) that it takes the actuator to go from fully closed to fully open or from fully open to fully closed. Should these values be different, the average value is used.

60 Seconds

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