Min Flow Control (VAV Dual Duct) Attributes - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 13.1

Controller Tool Help

Product name
Controller Configuration Tool
Document type
User Guide
Document number
LIT-12011147
Version
13.1
Revision date
2019-12-04

The following table describes the attributes used by the Application Mode Override module.

Table 1. Min Flow Control (VAV Dual Duct) Attributes
Name Type Description Default Value
CD Min Flow   When the mode is set to Cool, the Minimum Cold Deck Flow Setpoint output is fixed at the CD Min Flow input value. When the mode is set to Auto, the Minimum Cold Deck Flow Setpoint output value varies from 0 to the CD Min Flow. When the mode is set to Heat, the Minimum Cold Deck Flow is set to 0. 0.0
CD Percent Cmd   The flow setpoint rescaled between 0 and 100 percent. A value of 0% maps to the 0 CFM and 100% maps to Min Cold Deck Flow. 0.0
Control Status   Current status of the controller. Normal
Cooling Setpoint   When the mode is set to Auto, this setpoint indicates the zone temperature is near the cooling mode and needs minimum flow from the cold deck. 74 °F, 23 °C
Eff CD Min Flow   Calculated min flow for cold deck. 0.0
Eff HD Min Flow   Calculated min flow for hot deck. 0.0
HD Min Flow   When the mode is set to Heat, the Minimum Hot Deck Flow Setpoint output is fixed at the HD Min Flow input value. When the mode is set to Auto, the Minimum Hot Deck Flow Setpoint output value varies from 0 to the HD Min Flow. When the mode is set to Cool, the Minimum Hot Deck Flow is set to 0. 0.0
HD Percent Cmd   The flow setpoint rescaled between 0 and 100 percent. 0% maps to the 0 CFM and 100% maps to Min Hot Deck Flow. 0.0
Heating Setpoint   When the mode is set to Auto, indicates the zone temperature is near the heating mode and needs minimum flow from the hot deck. 70 °F, 21 °C
Min Absolute EWMA Effort   This value is an Exponentially Weighted Moving Average (EWMA). It is computed by the PID primitive and is based on the Current Present Value and the Last Present Value. It is the absolute value of the difference between the two. 0.0
Min Absolute EWMA Error   This value is an EWMA based on the absolute value of (Setpoint - Process Variable). 0.0
Min EWMA Error   This value is an EWMA based on the difference of (Setpoint - Process Variable). 0.0
Min EWMA Present Value   This value is an EWMA of the current Present Value. It is based on the difference of (Present Value - Last Present Value. 0.0
Mode  
  • Off: Output 50% min flow from each deck.
  • Auto: Calculated percentage from each deck based on where the zone temperature is within the deadband during satisfied mode.
  • Cool: 100% of minimum flow from the cold deck
  • Heat: 100% of the minimum flow from the hot deck.
  • Hold: Do not change the min flow setpoints during PID reset.
Auto
PID Tuning Reset   Used to reset the tuning parameters for the PID. Normal
Process ID   Used to configure the PID Pre-Processor. °F, °C
State   State indicates the current operational mode of the output controller. Min
Zone Temperature   When the mode input is set to Auto, the minimum flow setpoint outputs will be adjusted proportionally to the current temperature location in the dead band. 72 °F, 22 °C
1 C - Configuration Mode Only, G - Default Element (Generated State, if applicable), SC - Simulation and Commissioning Modes Only, V - Calculated Value (Outputs)