CrossVentilation_Sulzer

CrossVentilation_Sulzer (FB)

FUNCTION_BLOCK CrossVentilation_Sulzer

Short description

Control of cross ventilation using window elements via four independently adjustable characteristic curves Characteristic curve 1: Opening time depending on outside temperature Characteristic curve 2: Degree of opening depending on outside temperature Characteristic curve 3: Degree of opening depending on wind speed Characteristic curve 4: Waiting time depending on outside temperature Typical application: Control of cross ventilation by the room CO2 measured value\

Representation

Interfaces

Inputs

Name	Data type	Value range	Initial value	Function
xStartCrossVentilation	BOOL		FALSE	Start of cross ventilation (on every rising edge)
xAbortCrossVentilation	BOOL		FALSE	Abort cross ventilation (on every rising edge)
xEn_WT	BOOL		FALSE	Enable / disable the 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 the manual abort of the opening duration (on every 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 every 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 (_OT = Opening Time)
xActive_OT	BOOL		FALSE	Feedback - Active opening time (TRUE = active) (_OT = Opening Time)
rDegreeCurve_WDOO_OT	REAL		0.0	Current window opening degree [%] depending on outside temperature from the curve (_WDOO = Windows Degree Of Opening, _OT = OutsideTemp)
rDegreeCurve_WDOO_WS	REAL		0.0	Current window opening degree [%] depending on wind speed from the curve (_WDOO = Windows Degree Of Opening, _WS = Wind Speed)
rDegree_WDOO	REAL		0.0	Current window opening degree [%] (_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 limit value; if this is undershot no window opening will be started anymore.

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 characteristic 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): Characteristic curve 'Opening time depending on outside temperature'

2. Index _WDOO_OT (_WDOO = Windows Degree Of Opening, _OT = Outside Temp): Characteristic curve 'Degree of opening depending on outside temperature'

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

4. Index _WT (Waiting Time): Characteristic 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 characteristic 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 duration is calculated from characteristic curve 1. The degree of opening is determined and output from characteristic curves 2 and 3. After the completion of the window opening the waiting time, calculated from characteristic 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 characteristic curves contain valid data (xValidData_XX = TRUE)

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

Opening duration

After the successful start of cross ventilation the opening duration is calculated once from characteristic curve 1 depending on the current outside temperature. During the opening duration the status indicator 'xActive_OT' is active and the remaining time is output at 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 the successful start of cross ventilation the degree of opening is determined once from the two characteristic curves 2 and 3 depending on the current outside temperature and the current outside wind speed: Variable Z = (( value from characteristic curve 2 ) X ( value from characteristic 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 thus determined degree of opening is output at '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 must generally be enabled (xEn_WT = TRUE). At the beginning of the waiting time the duration is determined once from characteristic curve 4 depending on the outside temperature. During the active waiting time the status indicator 'xActive_WT' is active and the remaining time is output at 'tRemainingTime_WT'. The waiting time ends when the duration elapses or when the waiting time is disabled (xEn_WT = FALSE).

End of the opening time

The opening time ends immediately when the duration elapses (xEnComplete_OT = FALSE). The opening time ends after the duration has elapsed (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 the outside temperature

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

Input 'xResError'

Any rising edge on this input resets the outputs 'xError' and 'sErrorCode' to their respective non-error states.

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 was present. Currently the following error states are defined: '1': xValidData_OT = FALSE (Characteristic curve 1 without valid data) '2': xValidData_WDOO_OT = FALSE (Characteristic curve 2 without valid data) '3': xValidData_WDOO_WS = FALSE (Characteristic curve 3 without valid data) '4': xValidData_WT = FALSE (Characteristic curve 4 without valid data)

Typical application

The output 'xActive_WDOO' (= TRUE) signals the request to open the windows by cross ventilation, the output 'rDegree_WDOO' the degree of window opening in the range 0.0 - 100.0% (0.0% = closed). This function block can be used 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)