FB_BA_AC_SpTSuA_01

The template generates the supply air temperature setpoint of an air conditioning system, including summer and winter compensation.

The supply air temperature setpoint is determined by the function block Scale depending on the outside temperature.

The supply air temperature sequence control is enabled with the variable bOn by evaluating the receive block of the step sequence control Aggregate.

The setpoint linked to the variables fSpHtg, fSpCol and fSpErc is transferred to the supply air controllers of the aggregates heater, cooler and energy recovery.

Principle diagram 01

Principle diagram 02

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

Block diagram

Syntax

FUNCTION_BLOCK FB_BA_AC_SpTSuA_01 EXTENDS FB_BA_View
VAR_INPUT
  fTWth         : REAL;
END_VAR
VAR_OUTPUT
  fSpHtg        : REAL;
  fSpCol        : REAL;
  fSpErc        : REAL;
  bOn           : BOOL;
END_VAR
VAR_IN_OUT
  stAggregate   : ST_BA_Aggregate;
END_VAR
VAR_INPUT CONSTANT
  X1            : FB_BA_AV_Op;
  X2            : FB_BA_AV_Op;
  X3            : FB_BA_AV_Op;
  X4            : FB_BA_AV_Op;
  Y1            : FB_BA_AV_Op;
  Y2_3          : FB_BA_AV_Op;
  Y4            : FB_BA_AV_Op;
  Sp            : FB_BA_AV_Op;
  Aggregate     : FB_BA_Aggregate;
END_VAR
VAR
  PrioSwiVal    : FB_BA_PrioSwi_UDI04;
  MuxCmd        : FB_BA_MMUX_B04;
  Scale         : FB_BA_Chrct04;
END_VAR

Inputs

Name	Type	Description
fTWth	REAL	Current value of the outside temperature.

Outputs

Name	Type	Description
fSpHtg	REAL	Calculated setpoint of the supply air temperature for the heater.
fSpCol	REAL	Calculated setpoint of the supply air temperature for the cooler.
fSpErc	REAL	Calculated setpoint of the supply air temperature. for energy recovery.
bOn	BOOL	The output shows the resulting result of the multiplexer MuxCmd. This is further processed within the ventilation system and is used to enable the supply air temperature sequence control.

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
X1	FB_BA_AV_Op	Input of the value for interpolation point X1.
X2	FB_BA_AV_Op	Input of the value for interpolation point X2.
X3	FB_BA_AV_Op	Input of the value for interpolation point X3.
X4	FB_BA_AV_Op	Input of the value for interpolation point X4.
Y1	FB_BA_AV_Op	Input of the value for interpolation point Y1.
Y2_3	FB_BA_AV_Op	Input of the value for interpolation point Y2/Y3.
Y4	FB_BA_AV_Op	Input of the value for interpolation point Y4.
Sp	FB_BA_AV_Op	Output of the calculated, simple supply air temperature setpoint. This is output via the fSpHtg, fSpCol and fSpErc outputs.
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
bPrioSwiVal	FB_BA_PrioSwi_UDI04	The priority switch PrioSwiVal uses the command structure stCmd to determine the modulation command for the multiplexers MuxCmd and MuxMdlt.
MuxCmd	FB_BA_MMUX_B04	The multiplexer MuxCmd determines the current switch value from the command of the priority switch PrioSwiVal. The resulting output is sent to the binary output object bOn.
Scale	FB_BA_Chrct04	The function block calculates the supply air temperature setpoint depending on the outside temperature.

Requirements

Development environment	Necessary function
TwinCAT from v3.1.4024.35	TF8040 \| TwinCAT Building Automation from V5.0.0.0