BurnerT

BurnerT (FB)

FUNCTION_BLOCK BurnerT

Short description

Control of a heat generator (temperature setpoint via temperature signal) Typical application: heat generation

Representation

Function description

General

This function block is used to control a heat generator depending on the demand of the heat generator xEn and the supply setpoint temperature rSetPtTemp. The enable / disable of the heat generator is done via the output xHB (FALSE = lockout, TRUE = enable). The temperature signal is generated from the supply setpoint temperature rSetPtTemp by means of a linear characteristic curve defined by two points, if the heat generator is enabled ( xHB = TRUE). If the heat generator is locked out, the constant 0.0 is output. The following function blocks are essentially used:

TwoPoint

OperatingHours

ManBin

ManNum

Enable / disable of the heat generator xHB

The enabling of the heat generator ( xAB = TRUE, xHB = TRUE (eManModeB = eManBin.Auto)) occurs if the demand of the heat generator is active ( xEn = TRUE). The lockout of the heat generator ( xAB = FALSE, xHB = FALSE (eManModeB = eManBin.Auto)) occurs if the demand of the heat generator is not active ( xEn = FALSE).

Temperature signal for the heat generator rHA

The temperature signal for the heat generator is transmitted to the output rAA (and rHA, if eManModeN = eManNum.Auto) provided the heat generator is enabled ( xHB = TRUE). If the heat generator is locked out ( xHB = FALSE) the constant 0.0 is output. The temperature signal is generated from the supply setpoint temperature rSetPtTemp by means of a linear characteristic curve defined by two points and is absolutely limited to the range 0.0 - 100.0%. The input characteristic is defined by the setpoints / parameters rTwoPointX1 or rTwoPointX2 defined. The output characteristic is defined by the setpoints / parameters rTwoPointY1 or rTwoPointY2 defined. The line defined by the points P1 (X1 / Y1) and P2 (X2 / Y2) now allows the mapping of arbitrary supply setpoint temperatures rSetPtTemp to a temperature signal rAA. Example: Characteristic: X1 = 20.0, X2 = 90.0, Y1 = 20.0, Y2 = 100.0 &#xNAN;rSetPtTemp = 55.0 °C &#xNAN;rAA = 60.0 %

Manual override of the digital output xHB

The enable/disable of the heat generator ( xHB ) can be operated either in automatic mode ( eMANBIN.Auto ) or in one of the two manual modes ( eMANBIN.ManOn, eMANBIN.ManOff ).

xAB	eMANBIN	xHB	Notes
FALSE	eMANBIN.Auto	FALSE	Manual override module in automatic
TRUE	eMANBIN.Auto	TRUE	Manual override module in automatic
X	eMANBIN.ManOn	TRUE	Manual override module in manual operation On
X	eMANBIN.ManOff	FALSE	Manual override module in manual operation Off

Legend: X = don't care

Manual override of the analog output rHA

The temperature signal ( rHA ) can be operated either in automatic mode ( eMANNUM.Auto ) or in manual mode ( eMANNUM.Man ).

rAA	eMANNUM	rHA	Notes
Value	eMANNUM.Auto	Value	Manual override module in automatic
X	eMANNUM.Man	rManValue	Manual override module in manual operation

Legend: X = don't care

Aggregate fault xAlarm

The aggregate fault xAlarm is active ( = TRUE ) if the fault message of the heat generator xAlarmIn is active ( = TRUE ). In all other situations the aggregate fault xAlarm is not active ( = FALSE ).

Collective automatic mode message xAuto

The collective automatic mode message xAuto is set active ( = TRUE ) if the following conditions are met simultaneously:\

• Input eAOO = HVACTYPES.eManBin.Auto

• Input eAO = HVACTYPES.eManNum.Auto

• Setpoint / parameter eManModeB = eMANBIN.Auto

• Setpoint / parameter eManModeN = eMANNUM.Auto

Operating hours counter - heat generator

The operating hours counter ( udiOperatingHours, udiCountFb ) for the heat generator is active when the running feedback is active ( xFb = TRUE ).

Write access to the counters

Via the path ‘InstanceName._OperatingHours.udiOperatingHours’ or ‘InstanceName._OperatingHours.udiCountFb’ a write access to both counter values is possible.\

Prerequisite for the use of the function block BurnerT

The use of the TimeRead2 function block is required for correct operation.

Feedback of the heat generator output rU

The current actual Output of the heat generator can be connected to the input rU . This input is currently not used for control and regulation purposes.

Feedback of the manual value for the power signal from the manual override - hardware rPoti

The feedback of the manual value can be at the input rPoti . This input is currently not used for control and regulation purposes.

Inactive state ( xEn = FALSE )

xHB	xAB	rHA	rAA	dtLastFb	udiOperatingHours	udiCountFb	xAlarm	xAuto	Notes
FALSE ( eManModeB = eManBin.Auto )	FALSE	0.0 (eManModeN = eManNum.Auto)	0	old value	old value	old value	State of xAlarmIn	old value	xEn = FALSE

Legend: X = any\

CODESYS

InOut:

Scope	Name	Type	Initial
Input	xEn	BOOL
Input	rSetPtTemp	REAL
Input	xFb	BOOL
Input	rU	REAL	0
Input	xAlarmIn	BOOL
Input	eAOO	eManBin	eManBin.Auto
Input	eAO	eManNum	eManNum.Auto
Input	rPoti	REAL
Output	xHB	BOOL
Output	xAB	BOOL
Output	rHA	REAL
Output	rAA	REAL
Output	dtLastFb	DT
Output	udiOperatingHours	UDINT
Output	udiCountFb	UDINT
Output	xAlarm	BOOL
Output	xAuto	BOOL
Input Const	rTwoPointY2	REAL	100
Input Const	rTwoPointX2	REAL	90
Input Const	rTwoPointY1	REAL	20
Input Const	rTwoPointX1	REAL	20
Input Const	rManValue	REAL	0
Input Const	eManModeN	eMANNUM	eMANNUM.Auto
Input Const	eManModeB	eMANBIN	eMANBIN.Auto