SetPointCorrection

SetPointCorrection (FB)

FUNCTION_BLOCK SetPointCorrection

Short description

Generation of a setpoint temperature depending on the room deviation Principle: Linear offset Typical application: Adjustment of a supply setpoint temperature

Representation

Interfaces

Inputs

Name	Data type	Value range	Initial value	Function
rSupplyTempIn	REAL		0	Supply setpoint temperature from heating curve
rSetPointRoom	REAL		0	Room setpoint temperature
rRoomTemp	REAL		0	Current room temperature

Outputs

Name	Data type	Value range	Initial value	Function
rSupplyTempOut	REAL			corrected supply setpoint temperature
xMax	BOOL			Exceeding the maximum difference of the room temperature. (FALSE = not active, TRUE = active)
rCorrection	REAL			Display of the current correction
xAuto	BOOL			Manual-Auto override indicator: (FALSE = Manual, TRUE = Auto)
tDelay	TIME			Display of switch-back delay after exceedance

Setpoints / parameters

Name	Data type	Value range	Initial value	Function
tAlaTime	TIME		120	Restart time of the correction after the alarm begins.
rAlaLevel	REAL		5.0	Temperature deviation for alarm condition. In this state the correction is no longer applied.
rCorNeg	REAL	<= 0	-2.0	Maximum negative correction.
rCorPos	REAL	>= 0	2.0	Maximum positive correction.
rFactor	REAL		1.0	Correction of the setpoint per degree deviation of the room temperature.
rManValue	REAL		0.0	Manual override: manual value
eManModeN	eMANNUM	eMANNUM.Auto, eMANNUM.Man		Manual override: operating mode

Function description

General

The correction is applied proportionally between the room setpoint rSetPointRoom and the room temperature measurement rRoomTemp. The deviation is multiplied by the adjustable correction factor. This correction is applied to the supply setpoint rSetPointIn. The corrected setpoint is available at the output rSetpointOut. Maximum and minimum values can be freely parameterized for the correction. If the correction reaches the configured alarm level, it is considered a significant disturbance of the heated room and the setpoint is no longer corrected (e.g. window open). In this case the correction is disabled (rCorrection=0, rSetpointOut=W) and the binary output xMax is set to 1. After the configured restart time, the function attempts to reactivate the correction. If the correction is reactivated, the binary signal xMax resets to 0. The applied correction can be continuously observed at the output rCorrection.

Diagram

W = rSupplyTempIn (supply setpoint temperature from heating curve) Wi = rSetPointRoom (room setpoint temperature) Ti = rRoomTemp (current room temperature) Wc = rSupplyTempOut (corrected supply setpoint temperature) Max = xMax (Exceeding the maximum difference of the room temperature. (FALSE = not active, TRUE = active))

CODESYS

InOut:

Scope	Name	Type	Initial
Input	rSupplyTempIn	REAL	0
Input	rSetPointRoom	REAL	0
Input	rRoomTemp	REAL	0
Input Const	tMaxTime	TIME	TIME#2m0s0ms
Input Const	rMaxLevel	REAL	5
Input Const	rCorNeg	REAL	-2
Input Const	rCorPos	REAL	2
Input Const	rFactor	REAL	1
Input Const	rManValue	REAL	0
Input Const	eManModeN	eManNum	eManNum.Auto
Output	rSupplyTempOut	REAL
Output	xMax	BOOL
Output	rCorrection	REAL
Output	xAuto	BOOL
Output	tDelay	TIME