FB_BA_AC_OpModAggBinary

The template serves as a link between steps within the step sequence control of an air conditioning system.

The function block Step is the core of the template and represents the binary receive block of a step sequence controller.

The connected aggregate receives its commands via the command structure stCmd.

The data exchange to the control block of the step sequence control (StepCtrlAgg) takes place via the data and command structure stStep.

The four multiplexers OpModVal, DelayOn, DelayOff and IgnoreFdb define the switch-on and switch-off conditions of the plant step based on the plant operation mode eOpMode. Each of these multiplexers has an array to be parameterized for the output value of the multiplexers (arrOpModVal, arrIgnoreDelayOnVal, arrIgnoreDelayOffVal, arrIgnoreFdbVal).

The resulting values of the multiplexers bVal, _bFdb, nDelayOn and nDelayOff are transmitted to the receive block of the step sequence controller Step, see block diagram part 02.

The parameterization of the arrays can be found in an air conditioning system in the methods below the example template FB_BA_AC_PlantCmd_AHU_1st_10, see Methods.

Block diagram

Part 01

Part 02

Syntax

FUNCTION_BLOCK FB_BA_AC_OpModAggBinary
VAR_INPUT
  stPriorityEn             : ST_BA_PriorityEn;
  eOpMode                  : E_BA_AC_OpMod01;
  bFdb                     : BOOL;
  fDlyOn                   : REAL;
  fDlyOff                  : REAL;
END_VAR
VAR_OUTPUT
  stCmd                    : ST_BA_Binary;
  nRemSecStepUp            : UDINT;
  nRemSecStepDown          : UDINT;
END_VAR
VAR_IN_OUT
  stStep                   : ST_BA_Step;
END_VAR
VAR_INPUT CONSTANT
  OpModVal                 : FB_BA_MMUX_B16;
  DelayOn                  : FB_BA_MMUX_B16;
  DelayOff                 : FB_BA_MMUX_B16;
  IgnoreFdb                : FB_BA_MMUX_B16;
  Step                     : FB_BA_StepBinary;
END_VAR
VAR_INPUT CONSTANT PERSISTENT
  bInit                    : BOOL := TRUE;
  arrOpModVal              : ARRAY [1..16] OF BOOL;
  arrIgnoreDelayOnVal      : ARRAY [1..16] OF BOOL;
  arrIgnoreDelayOffVal     : ARRAY [1..16] OF BOOL;
  arrIgnoreFdbVal          : ARRAY [1..16] OF BOOL;
END_VAR
VAR
  bVal                     : BOOL;
  _bFdb                    : BOOL;
  nDelayOn                 : UDINT;
  nDelayOff                : UDINT;
END_VAR

Inputs

Name	Type	Description
stPriorityEn	ST_BA_PriorityEn	Input of the current command structure stPriorityEn. This includes the system enable for the step sequence control of an air conditioning system and the associated enables for the priorities "Safety", "Critical" and "Program".
eOpMode	E_BA_AC_OpMod01	Input of the current operation mode.
bFdb	BOOL	Feedback from the connected aggregate of the step sequence controller. The feedback is required for switching to the next step. bFdb is only considered if the aggregate is the active one in the step sequence control. By parameterizing the individual elements of the array arrIgnoreFdbVal with a TRUE, the feedback from the aggregate can be ignored for the different operation modes eOpMode.
fDlyOn	REAL	Time specification of the start-up delay [s]. The time specification is required for switching to the next step. By parameterizing the individual elements of the array arrIgnoreDelayOnVal with a TRUE, the start-up delay of the step can be ignored for the different operation modes eOpMode.
fDlyOff	REAL	Time specification of switch-off delay [s]. The time specification is needed to switch off the active step. By parameterizing the individual elements of the array arrIgnoreDelayOffVal with a TRUE, the switch-off delay of the step can be ignored for the different operation modes eOpMode.

Outputs

Name	Type	Description
stCmd	ST_BA_Binary	The command structure stCmd transmits the enables and switching values of the priorities to the connected aggregate.
nRemSecStepUp	UDINT	Countdown to switch on the next step [s].
nRemSecStepDown	UDINT	Countdown to switching off the active step [s].

Inputs/outputs

Name	Type	Description
stStep	ST_BA_Step	Data and command structure between the step sequence function block FB_BA_StepBinary and the control block of the step sequence FB_BA_StepCtrlAgg16.

Inputs CONSTANT

Name	Type	Description
OpModVal	FB_BA_MMUX_B16	The multiplexer determines the switch-on value of the connected aggregate. The resulting value is sent to the output bVal.
DelayOn	FB_BA_MMUX_B16	The multiplexer and the connected network of functions determine the switching delay to the next step. The resulting value is sent to the output nDelayOn.
DelayOff	FB_BA_MMUX_B16	The multiplexer and the connected network of functions determine the switch-off delay of the current step. The resulting value is sent to the output nDelayOff.
IgnoreFdb	FB_BA_MMUX_B16	The multiplexer and the connected network of functions determine the feedback of the aggregate. The resulting value is sent to the output _bFdb.
Step	FB_BA_StepBinary	The function block represents the binary receive block of a step sequence controller and controls the connected aggregate via the command structure stCmd. The data exchange to the control block of the step sequence control (FB_BA_StepCtrlAgg16) takes place via the data and command structure stStep.

Inputs CONSTANT PERSISTENT

Name	Type	Description
bInit	BOOL	The variable is used to initialize the arrays arrOpModVal, arrIgnoreDelayOnVal, arrIgnoreDelayOffVal, arrIgnoreFdbVal in the methods below the template FB_BA_AC_PlantCmd_AHU_1st_10. After starting the controller, the variable is set to FALSE after a PLC cycle and this state is saved persistently.
arrOpModVal	ARRAY [1..16] OF BOOL	By parameterizing the individual elements of the array, the switch-on value of the connected aggregate can be defined on the step sequence function block for the different operation modes eOpMode.
arrIgnoreDelayOnVal	ARRAY [1..16] OF BOOL	By parameterizing the individual elements of the array with a TRUE, the switching delay to the next step within the step sequence control can be ignored for the different operation modes eOpMode.
arrIgnoreDelayOffVal	ARRAY [1..16] OF BOOL	By parameterizing the individual elements of the array with a TRUE, the switch-off delay of the current step within the step sequence control can be ignored for the different operation modes eOpMode.
arrIgnoreFdbVal	ARRAY [1..16] OF BOOL	By parameterizing the individual elements of the array with a TRUE, the feedback from the aggregate bFdb can be ignored for the different operation modes eOpMode.

Variables

Name	Type	Description
bVal	BOOL	The variable is the result of the operation mode eOpMode, the multiplexer OpModVal and the array arrOpModVal. bVal defines the switch-on value at the step sequence function block Step.
_bFdb	BOOL	The variable is the result of the operation mode eOpMode, the multiplexer IgnoreFdb and the array arrIgnoreFdbVal. _bFdb defines the switching condition to the next step in the step sequence function block Step.
nDelayOn	UDINT	The variable is the result of the operation mode eOpMode, the multiplexer DelayOn and the array arrIgnoreDelayOnVal. nDelayOn defines the switching delay to the next step on the step sequence function block Step.
nDelayOff	UDINT	The variable is the result of the operation mode eOpMode, the multiplexer DelayOff and the array arrIgnoreDelayOffVal. nDelayOff defines the switch-off delay of the current step on the step sequence function block Step.

Requirements

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