CrossVentilation_Sulzer

CrossVentilation_Sulzer (FB)

FUNCTION_BLOCK CrossVentilation_Sulzer

Short description

Control of cross-ventilation using window elements via four separately adjustable characteristic curves Curve 1: Opening time depending on outside temperature Curve 2: Degree of opening depending on outside temperature Curve 3: Degree of opening depending on wind speed Curve 4: Waiting time depending on outside temperature Typical application: Control of cross-ventilation by the room CO2 actual value

Representation

Interfaces

Inputs

Name	Data type	Value range	Initial value	Function
xStartCrossVentilation	BOOL		FALSE	Start of cross-ventilation (on each rising edge)
xAbortCrossVentilation	BOOL		FALSE	Abort cross-ventilation (on each rising edge)
xEn_WT	BOOL		FALSE	Enable / disable waiting time (TRUE = enabled)
xEnComplete_OT	BOOL		FALSE	Enable / disable the input ‘xComplete_OT’ (FALSE = disabled) (_OT = Opening Time)
xComplete_OT	BOOL		FALSE	Enable / disable manual abort of the opening duration (on each rising edge, if xEnComplete_OT = TRUE) (e.g. abort via CO2 level after the opening duration has elapsed)
rOutsideTemp	REAL		0.0	Outside temperature
rOutsideWindSpeed	REAL		0.0	Wind speed
xResError	BOOL		FALSE	Reset of the outputs ‘xError’ and ‘sErrorCode’ (on each rising edge)
xValidData_OT	BOOL		FALSE	Validity of the data of the curve ‘Opening Time - Outside Temperature’ (_OT = Opening Time) (TRUE = valid)
xValidData_WDOO_OT	BOOL		FALSE	Validity of the data of the curve ‘Window Degree Of Opening - Outside Temperature’ (_WDOO = Windows Degree Of Opening, _OT = OutsideTemp) (TRUE = valid)
xValidData_WDOO_WS	BOOL		FALSE	Validity of the data of the curve ‘Window Degree Of Opening - Wind Speed’ (_WDOO = Windows Degree Of Opening, _WS = Wind Speed) (TRUE = valid)
xValidData_WT	BOOL		FALSE	Validity of the data of the curve ‘Waiting Time - Outside Temperature’ (_WT = Waiting Time) (TRUE = valid)

Inputs and outputs

Name	Data type	Value range	Initial value	Function
arData_OT	stCurve_Real_Time			Array with the support points for the curve ‘Opening Time - Outside Temperature’ (_OT = Opening Time)
arData_WDOO_OT	stCurve_Real_Real			Array with the support points for the curve ‘Window Degree Of Opening - Outside Temperature’ (_WDOO = Windows Degree Of Opening, _OT = OutsideTemp)
arData_WDOO_WS	stCurve_Real_Real			Array with the support points for the curve ‘Window Degree Of Opening - Wind Speed’ (_WDOO = Windows Degree Of Opening, _WS = Wind Speed)
arData_WT	stCurve_Real_Time			Array with the support points for the curve ‘Waiting Time - Outside Temperature’ (_WT = Waiting Time)

Outputs

Name	Data type	Value range	Initial value	Function
tTimeCurve_OT	TIME		T#0s	Current opening time duration from the curve (_OT = Opening Time)
tRemainingTime_OT	TIME		T#0s	Remaining time of the active opening time duration (_OT = Opening Time)
xActive_OT	BOOL		FALSE	Feedback - Active opening time duration (TRUE = active) (_OT = Opening Time)
rDegreeCurve_WDOO_OT	REAL		0.0	Current window degree of opening [ % ] depending on outside temperature from the curve (_WDOO = Windows Degree Of Opening, _OT = OutsideTemp)
rDegreeCurve_WDOO_WS	REAL		0.0	Current window degree of opening [ % ] depending on wind speed from the curve (_WDOO = Windows Degree Of Opening, _WS = Wind Speed)
rDegree_WDOO	REAL		0.0	Current window degree of opening [ % ] (_WDOO = Windows Degree Of Opening)
xActive_WDOO	BOOL		FALSE	Feedback - Active window opening (TRUE = active) (_WDOO = Windows Degree Of Opening)
tTimeCurve_WT	TIME		T#0s	Current waiting time from the curve (_WT = Waiting Time)
tRemainingTime_WT	TIME		T#0s	Remaining time of the active waiting time (_WT = Waiting Time)
xActive_WT	BOOL		FALSE	Feedback - Active waiting time (TRUE = active) (_WT = Waiting Time)
xError	BOOL		FALSE	Error state (FALSE = no error, TRUE = error)
sErrorCode	STRING		‘’	String with the numbers of the active errors

Setpoints / parameters

Name	Data type	Value range	Initial value	Function
rOutsideTempLimit	REAL		-15	Outside temperature threshold, below which no window opening will be initiated.

Function description

Characteristic curves

The total of four freely adjustable characteristic curves (each with 10 support points, FB ‘Curve_10XY_Real’ or FB ‘Curve_10XY_Real_Time’) are connected to the associated data inputs (arData_XX), as well as the outputs of the curves that signal the validity of the data (xValidData_XX). The assignment of the characteristic curves to the inputs is fixed as follows:

1. Index _OT (Opening Time): Curve ‘Opening time depending on outside temperature’

2. Index _WDOO_OT (_WDOO = Windows Degree Of Opening, _OT = Outside Temp): Curve ‘Degree of opening depending on outside temperature’

3. Index _WDOO_WS (_WDOO = Windows Degree Of Opening, _WS = Wind Speed): Curve ‘Degree of opening depending on outside wind speed”

4. Index _WT (Waiting Time): Curve ‘Waiting time depending on outside temperature’

If an input value (= X-value) outside the range specified by support points 1 and 10 is passed to a curve, the Y-value of the nearest support point is returned (example: support point 1 (1, 10), support point 10 (10, 100), X-value = -5 — Y-value = 10)

Procedure

Cross-ventilation is started with a rising edge at the input ‘xStartCrossVentilation’. The opening time duration is calculated from curve 1. The degree of opening is determined and output from curves 2 and 3. After the window opening is completed, the waiting time calculated from curve 4 is started, which temporarily prevents another cross-ventilation.

Start of cross-ventilation

Cross-ventilation is started with a rising edge at the input ‘xStartCrossVentilation’ if all of the following conditions are met:

1. The waiting time is not active (xActive_WT = FALSE)

2. The opening time is not active (xActive_OT = FALSE)

3. All four curves contain valid data (xValidData_XX = TRUE)

4. The outside temperature exceeds the absolute minimum limit (rOutsideTemp > rOutsideTempLimit)

Opening duration

After successful start of cross-ventilation, the opening time duration is calculated once from curve 1 depending on the current outside temperature. During the opening time duration, the status indicator ‘xActive_OT’ is active and the remaining time duration is output on the output ‘tRemainingTime_OT’.

Abort

The active cross-ventilation can be aborted at any time by a rising edge at the input ‘xAbortCrossVentilation’.

Degree of opening

After successful start of cross-ventilation, the degree of opening is determined once from the two curves 2 and 3 depending on the current outside temperature and the current outside wind speed: Variable Z = ((Value from curve 2) X (Value from curve 3)) / 100 The variable Z is then compared with fixed predefined range limits and the degree of opening assigned to the respective range is output: 0 <= Z < 15: Degree of opening = 0% 15 <= Z < 25: Degree of opening = 25% 25 <= Z < 50: Degree of opening = 50% 50 <= Z < 75: Degree of opening = 75% Z > 75 : Degree of opening = 100% The determined degree of opening is output at the output ‘rDegree_WDOO’, the output ‘xActive_WDOO’ signals an active window opening (= TRUE).

Waiting time

Directly after the end of the opening duration, a possible waiting time until the next activation of cross-ventilation begins. For this, the waiting time duration must generally be enabled (xEn_WT = TRUE). At the start of the waiting time, the duration is determined once from curve 4 depending on the outside temperature. During the active waiting time the status indicator ‘xActive_WT’ is active and the remaining time duration is output at the output ‘tRemainingTime_WT’. The waiting time ends when the duration expires or when the waiting time is disabled (xEn_WT = FALSE).

End of opening time

The opening time ends immediately when the duration elapses (xEnComplete_OT = FALSE). The opening time ends after the duration elapses (xEnComplete_OT = TRUE) if a rising edge is detected at the input ‘xComplete_OT’. This serves to extend the opening duration until an acceptable CO2 level is reached.

Blocking cross-ventilation via outside temperature

Cross-ventilation is only started if the current outside temperature at the start time exceeds the adjustable limit ‘rOutsideTempLimit’.

Input ‘xResError’

Each rising edge on this input resets the outputs ‘xError’ and ‘sErrorCode’ to their respective no-error state.

Output ‘xError’

The output is active (= TRUE) if at least one error has been detected (‘sErrorCode <> ‘‘).

Output ‘sErrorCode’

This output signals the current error status. An empty string ‘’ indicates that no error is present. Currently the following error states are defined: ‘1’: xValidData_OT = FALSE (Curve 1 without valid data) ‘2’: xValidData_WDOO_OT = FALSE (Curve 2 without valid data) ‘3’: xValidData_WDOO_WS = FALSE (Curve 3 without valid data) ‘4’: xValidData_WT = FALSE (Curve 4 without valid data)

This function block can be applied as follows:

The output ‘xActive_WDOO’ (= TRUE) signals the request to open the windows for cross-ventilation, the output ‘rDegree_WDOO’ the window opening degree in the range 0.0 - 100.0% (0.0% = closed). This function block can be applied as follows:

CODESYS

InOut:

Scope	Name	Type	Initial
Input	xStartCrossVentilation	BOOL	FALSE
Input	xAbortCrossVentilation	BOOL	FALSE
Input	xEn_WT	BOOL	TRUE
Input	xEnComplete_OT	BOOL	FALSE
Input	xComplete_OT	BOOL	FALSE
Input	rOutsideTemp	REAL	0.0
Input	rOutsideWindSpeed	REAL	0.0
Input	xResError	BOOL	FALSE
Input	xValidData_OT	BOOL	FALSE
Input	xValidData_WDOO_OT	BOOL	FALSE
Input	xValidData_WDOO_WS	BOOL	FALSE
Input	xValidData_WT	BOOL	FALSE
Input	arData_OT	POINTER TO stCurve_Real_Time
Input	arData_WDOO_OT	POINTER TO stCurve_Real_Real
Input	arData_WDOO_WS	POINTER TO stCurve_Real_Real
Input	arData_WT	POINTER TO stCurve_Real_Time
Output	tTimeCurve_OT	TIME	TIME#0ms
Output	tRemainingTime_OT	TIME	TIME#0ms
Output	xActive_OT	BOOL	FALSE
Output	rDegreeCurve_WDOO_OT	REAL	0.0
Output	rDegreeCurve_WDOO_WS	REAL	0.0
Output	rDegree_WDOO	REAL	0.0
Output	xActive_WDOO	BOOL	FALSE
Output	tTimeCurve_WT	TIME	TIME#0ms
Output	tRemainingTime_WT	TIME	TIME#0ms
Output	xActive_WT	BOOL	FALSE
Output	xError	BOOL	FALSE
Output	sErrorCode	STRING	‘’
Input Const	rOutsideTempLimit	REAL	-15.0

Methods:

mCalculateCurveSectionValue_Real_Real

mCalculateCurveSectionValue_Real_Time

mCalculateCurveValue_Real_Real

mCalculateCurveValue_Real_Time

mResData

Structure:

• mCalculateCurveSectionValue_Real_Real (Method)

• mCalculateCurveSectionValue_Real_Time (Method)

• mCalculateCurveValue_Real_Real (Method)

• mCalculateCurveValue_Real_Time (Method)

• mResData (Method)