FB_BA_AC_FanCtl

The aggregate template represents the control and regulation of a pressure-controlled fan. Typical applications for this template are the supply and exhaust air fans of an air conditioning system with variable volume flow rate.

The basic template FB_BA_MotCtl is extended by two binary inputs for detecting an additional fault and a maintenance switch.

The input bDamperOpen prevents the fan from starting when the damper is closed.

The pressure-controlled fan is integrated into the control program of the air conditioning system using the function block Aggregate and the inputs and outputs structure stAggregate.

Each template is available in 2 different configurations regarding the connection to the I/O process level, see I/O mapping. This documentation refers to the RAW variant.

	The initialization of the template takes place within the method FB_Init.

Principle diagram 01

The diagram shows the intended use of the template with the plant elements involved.

Principle diagram 02

The diagram shows the integration of the template within a plant.

Block diagram

Syntax

FUNCTION_BLOCK FB_BA_AC_FanCtl EXTENDS FB_BA_MotCtl
VAR_INPUT
  bDamperOpen      : BOOL;
END_VAR
VAR_IN_OUT
  stAggregate      : ST_BA_Aggregate;
END_VAR
VAR_INPUT CONSTANT
  ThOvrld          : FB_BA_BI_Raw;
  MntnSwi          : FB_BA_BI_Raw;
  Aggregate        : FB_BA_Aggregate;
END_VAR
VAR
  PrioSwiDamper    : FB_BA_PrioSwi_UDI04;
END_VAR

Inputs

Name	Type	Description
bDamperOpen	BOOL	The input signal "Damper open" is used within a air conditioning system to protect the connected damper. As long as the input signal "Damper open" is not TRUE, the priority "Critical" is enabled on the priority switch PrioSwiDamper within the template and the fan is switched off.

Name

Type

Description

bDamperOpen

BOOL

The input signal "Damper open" is used within a air conditioning system to protect the connected damper.

As long as the input signal "Damper open" is not TRUE, the priority "Critical" is enabled on the priority switch PrioSwiDamper within the template and the fan is switched off.

Inputs/outputs

Name	Type	Description
stAggregate	ST_BA_Aggregate	Bidirectional aggregate structure via which the enables and switching values are transmitted to the evaluation function block of the step sequence control Aggregate. The aggregate structure transmits the recorded feedback signals up and down to the central plant control.

Inputs CONSTANT

Name	Type	Description
ThOvrld	FB_BA_BI_Raw	The binary input object is used to process the "Thermal overload" fault.
MntnSwi	FB_BA_BI_Raw	The binary input object is used to process a maintenance switch.
Aggregates	FB_BA_Aggregate	The aggregate function block represents a receive block of a step sequence controller. Within the function block, the aggregate structure stAggregate is evaluated and integrated into the template using the inputs and outputs.

Name

Type

Description

ThOvrld

FB_BA_BI_Raw

The binary input object is used to process the "Thermal overload" fault.

MntnSwi

FB_BA_BI_Raw

The binary input object is used to process a maintenance switch.

Aggregates

FB_BA_Aggregate

The aggregate function block represents a receive block of a step sequence controller.

Within the function block, the aggregate structure stAggregate is evaluated and integrated into the template using the inputs and outputs.

Variables

Name	Type	Description
PrioSwiDamper	FB_BA_PrioSwi_UDI04	The priority switch PrioSwiDamper uses the aggregate function block Aggregate and the input variable bDamperOpen to determine the enable conditions and switch-on values for the priority "Critical" of the fan.

Requirements

Development environment	Necessary function
TwinCAT from v3.1.4024.56	TF8040 \| TwinCAT Building Automation from V5.8.0.0