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