Attributes (Loss of Airflow Sequencing) - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 13.1

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Johnson Controls
Product name
Controller Configuration Tool
Document type
User Guide
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The following table describes the attributes used by the Loss of Airflow Sequencing module.

Table 1. Loss of Airflow Sequencing Attributes



Default Value

Air Proving Switch

Proof of airflow input. This is an enumerated input with two possible values: Off and On.


Set Name: Off/On


Defines the maximum time required for the fan to prove. If the fan is commanded on and does not prove within this time, the unit enters either the manual recovery fault state or the self recovery fault state.

30 Seconds

Electric Heat

Indicates when electric heat is used. Units with electric heat may require low flow protection.


Flow Debounce

Defines the amount of time the module ignores a temporary loss of airflow before it takes action.

10 Seconds

Hardware Restart

Provides a hardware binary input for fault recovery.


Set Name: Normal/Trigger

Min Air Flow Setpoint

Defines the minimum amount of airflow required for operating the electric heat.

200 l/s, 424 cfm

Network Restart

Provides a network input for fault recovery.


Set Name: Normal/Trigger


Current state of the activity. This output is connected to the state selection matrix.

Set Name: AHU Flow States

See Primary States (Loss of Airflow Sequencing).

Proof of Airflow

Shows the current airflow status. The output may be True, False, or Fault. True means the fan was commanded on and airflow has been detected. False means the fan was not commanded on. Fault means the fan was commanded on, but airflow proof has not been detected. This output would be connected to the MSC module Proof of Airflow input for a staged device.

Set Name: False/True/Fault

Restart Config

Configures the sequencer for manual fault recovery. When set to True, a fault requires manual intervention for recovery. When set to False, the unit may self recover. To exit the manual reset mode, the operator must use the Hardware Restart or the Network Restart inputs to clear the fault.


Supply Fan OnOff

Supply fan command. The activity uses this input to determine if the fan was commanded on or off.


Set Name: Off/On

Supply Fan Status

Shows the current airflow status. The output may be either True when there is proof of airflow or False when there is not. This output would be connected to the Free Cooling Availability module Supply Fan Status input.


Supply Flow

Contains the airflow measurement. This input may be used on a unit with electric heat to make sure the heating coils have enough airflow.

200 l/s, 424 cfm