OptStartHeat32

OptStartHeat32 (FB)

FUNCTION_BLOCK OptStartHeat32 EXTENDS Uhr_Base IMPLEMENTS IUhr

Short description

Switch-on optimization for heating operation with a connection to the FB ‘ClockSlave32’ (principle: variable preheating time) Goal: Room temperature = setpoint temperature at the start of daytime operation Typical application: zone control loop with heating valve\

Representation

Interfaces

Inputs

Name	Data type	Value range	Initial value	Function
itfFromClockMaster	IUhrProtocol			Interface for connecting to the FB ‘ClockMaster32’
ClockSlaveParam	stSlvClockData			Connection to some selected parameters of the FB ‘ClockSlave32’
xEn	BOOL		FALSE	General enable of the switch-on optimization
xEnAdapt	BOOL		TRUE	Enable storage of data in the historical memory
xResAdapt	BOOL		TRUE	Reset of the historical memory
rTo	REAL			Current outdoor temperature
rTi	REAL			Current room temperature
rSetTemp	REAL			Current room setpoint temperature in comfort/daytime operation

Outputs

Name	Data type	Value range	Initial value	Function
xDaytime	BOOL		FALSE	Enable comfort/daytime operation (Off = FALSE, On = TRUE)
xProcess	BOOL		FALSE	Enable - preheating process (Off = FALSE, On = TRUE)
bState	BYTE		0	Phase of the preheating process (0=Off/Deactivated, 1 = Check time, 2 = Dead time, 3 = Heating time, 4 = End of heating time)
wError	WORD		0	Error status of the last preheating process
bResult	BYTE		0	Quality of the last preheating process (0 = invalid, 1 = good, 2 = normal, 3 = poor)
xActive	BOOL		FALSE	State of the clock channel (Off = FALSE, On = TRUE)
uiDeadTime	UINT		0	Display of the current dead time duration (min)
uiHeatTime	UINT		0	Display of the current heating time duration (min)
uiNumber	UINT		0	Display of the total number of successful preheating processes
rAverageDiff	REAL		0.0	Average absolute room temperature deviation of the last 10 successful preheating processes

Setpoints / Parameters

Name	Data type	Value range	Initial value	Function
uiHGMin	UINT		30	Minimum value - heating gradient (min/K)
uiHGMax	UINT		240	Maximum value - heating gradient (min/K)
uiDTMin	UINT		10	Minimum value - dead time (min)
uiDTMax	UINT		180	Maximum value - dead time (min)
uiHTMin	UINT		15	Minimum value - heating time (min)
uiHTMax	UINT		600	Maximum value - heating time (min)

Global variables

Name	Data type	Value range	Initial value	Function
gc_Parameters.rTOMin	REAL		-25	Minimum value - outdoor temperature (°C)
gc_Parameters.rTOMax	REAL		25	Maximum value - outdoor temperature (°C)
gc_Parameters.rTIMin	REAL		15	Minimum value - room temperature (°C)
gc_Parameters.rTIMax	REAL		30	Maximum value - room temperature (°C)
gc_Parameters.rDiffSetTemp	REAL		0	Deviation from the room setpoint temperature at the end of the preheating process (K)
gc_Parameters.rDTDiffTemp	REAL		0.2	Increase in room temperature to detect the end of the dead time (K)
gc_Parameters.uiPHMaxTime	UINT		720	Maximum duration of the preheating process
gc_Parameters.rLimitResultWell	REAL		0.5	Result display: room temperature deviation - limit value for a good preheating process
gc_Parameters.rLimitResultNormal	REAL		1	Result display: room temperature deviation - limit value for a normal preheating process

Restrictions / boundary conditions

1) This FB does not allow preheating processes across days. The preheating process can therefore start at the earliest at 00:01 on each weekday. Example: Start - comfort operation: Monday - 05:30 // Calculated preheating time = 7 hours Optimal start time - preheating process: Sunday - 22:30 Actual start time - preheating process: Monday - 00:01 2) Special switching times, if assigned (FB ‘ClockSlave32’: parameter ‘xSwitchTimeS’ = TRUE) and active (FB ‘ClockMaster32’: output ‘xSwitchTimeS’ = TRUE), do not start a preheating process and immediately abort any preheating process that may be active. 3) The value of the output ‘ctClockSlave32’ of the FB ‘ClockMaster32’ is incremented by one by each instance of the FB ‘OptStartHeat32’. \

Function description

The output xDaytime is activated by the switch-on optimization (xEn = TRUE) depending on the historical data, the current outdoor temperature, the current room temperature, and the current setpoint temperature for daytime/comfort operation before the planned start of comfort/daytime operation. This preheating ensures that the room temperature already corresponds to the desired setpoint temperature at the start of daytime operation. The preheating time required for this is recalculated individually for each preheating process; the actual preheating time is also included in the historical data. Preheating processes across days are not possible. The switch-on optimization serves to save energy and increase user comfort. The components relevant to the switch-on optimization are processed every 60s. A new preheating process is not started, or an active preheating process is interrupted, if at least one of the following conditions described is met: 1) Holiday channel active (FB ‘ClockMaster32’ - xHoliday = TRUE AND FB ‘ClockSlave32’ - ClockSlaveParam.xHoliday = TRUE) 2) Public holiday channel active (FB ‘ClockMaster32’ - xPublicHoliday = TRUE AND FB ‘ClockSlave32’ - ClockSlaveParam.xPublicHoliday = TRUE) 3) Special switching times channel active (FB ‘ClockMaster32’ - xSwitchTimeS = TRUE AND FB ‘ClockSlave32’ - ClockSlaveParam.xSwitchTimeS = TRUE) 4) Central command ON active (FB ‘ClockMaster32’ - xAllOn = TRUE) 5) Central command OFF active (FB ‘ClockMaster32’ - xAllOff = TRUE) The preheating process is divided into four time sections. They are run through one after the other in every successful preheating process. The preheating process can end before, exactly at, or after the switch-on point (= transition to comfort/daytime operation).\

Check time (bState = 1)

The check time is used for cyclic checking (every 60s) whether the conditions for releasing preheating are met. It begins if the following conditions are simultaneously met: \

1. The preheating process is not active ( xProcess = FALSE )\

2) The clock channel is not active (xActive = FALSE) 3) A valid next switch-on point exists It ends properly if the conditions for releasing preheating are met (= start of dead time). It ends in any case if the next valid switch-on point equals the current time.\

Dead time (bState = 2)

The dead time is used for preconditioning the heating. It begins with the proper end of the check time. It ends properly if the current room temperature rTi exceeds the room temperature at the start of dead time by the adjustable difference gc_Parameters.rDTDiffTemp permanently for a duration of at least 120s (= start of heating time). It ends in any case if the next valid switch-on point equals the current time. \

Heating time (bState = 3)

The heating time is used for preheating the zone. It begins with the proper end of the dead time. It ends properly if the current room temperature rTI the current room setpoint temperature in comfort/daytime operation rSetTemp approaches permanently for a duration of at least 120s to a difference smaller than the global variable gc_Parameters.rDiffSetTemp It ends if a falling signal edge is detected on the state of the clock channel xActive It ends if the current heating time duration exceeds the adjustable maximum value uiHTMax . \

End of heating time (bState = 4)

The end of the heating time serves to complete the successful preheating process. The historical data are updated, provided no limits are violated, if the enabling of data storage in the historical memory ( xEnAdapt ) is active. It begins with the proper end of the heating time. \

Enable xEn

This input serves to generally enable the switch-on optimization ( xEn = TRUE). In the locked state ( xEn = FALSE) the outputs are defined as follows:\

Output	State/Value	Notes
xDaytime	FALSE
xProcess	FALSE
bState	0
wError	0
bResult	0
uiDeadTime	0
uiHeatTime	0
uiNumber	0
rAverageDiff	0

The historical data are retained even in the locked state. This input can also be used to switch in sensor faults (fault - room temperature sensor, fault outdoor temperature sensor) or for operating the zone in the extended operating time. \

Enable xEnAdapt

This input is used to enable data storage in the historical memory ( xEnAdapt = TRUE, prerequisite: xEn = TRUE). After each successful preheating process, the relevant parameters are stored and are thus available again for the next preheating process. In the locked state ( xEnAdapt = FALSE) no data storage takes place. \

Enable xResAdapt

This input is used to initialize the historical memory at each rising signal edge (prerequisite: xEn = TRUE).\

Memory	State/Value	Notes
Heating gradients	uiHGMax
Dead times	uiDTMax
Number of preheating processes	0

Additionally, the buffer for the average absolute room temperature deviation of the last 10 successful preheating processes and the data store for the current data are reset. \

Meaningful use of the input xResAdapt

This input can be used in combination with the output rAverageDiff (Average absolute room temperature deviation of the last 10 successful preheating processes) to trigger reinitialization of the historical and current data in case of larger deviations.\

Input rTo

This input is used to capture the current outdoor temperature. For the switch-on optimization it is additionally time-filtered and limited (Minimum value = gc_Parameters.rTOMin, Maximum value = gc_Parameters.rTOMax ). \

Input rTi

This input is used to capture the current room temperature. For the switch-on optimization it is additionally time-filtered and limited (Minimum value = gc_Parameters.rTIMin, Maximum value = gc_Parameters.rTIMax ). \

Input rSetTemp

This input is used to capture the current room setpoint temperature for comfort/daytime operation. Each change in the setpoint triggers a reset to the basic state (see Enable xEn - locked state). \

Output xDaytime

This output is used to enable comfort/daytime operation (Off = FALSE, On = TRUE) by the switch-on optimization. It is activated on the transition from check time to dead time. It is deactivated when the next valid switch-on point is reached. \

Output xProcess

This output is used to indicate the active preheating process (Off = FALSE, On = TRUE). It is active if the preheating process is in phases 1 - 4 and/or the output xDaytime is active. \

Output bState

This output is used to indicate the active phase of the preheating process.\

Value	Phase
0	Off / Deactivated
1	Check time active
2	Dead time active
3	Heating time active
4	End of heating time active

Output wError

This output is used to indicate warnings/errors during the last preheating process. Each message is assigned a bit (Bit = 0 = no error, Bit = 1 = warning/error active). This output is permanently updated. On each change, the date/current time is also captured. This output is always initialized to 0 (= no error) at the start of the check time. On each occurrence of an error, the preheating process is stopped and the ‘Off / Deactivated’ phase is initiated. On each occurrence of a warning, the output wError is updated.\

Bit	Cause	Error type	Notes
1	Exceeding the maximum heating time	Error
4	Limit violation heating gradient	Warning
5	Limit violation dead time	Warning
6	Undershooting the minimum heating time	Warning

Output bResult

This output is used to indicate the quality of the last successful preheating process. The output is updated at the switch-on point (= transition to comfort/daytime operation) if required. The absolute value from the calculation of rSetTemp - gc_Parameters.rDiffSetTemp - rTi is used for the evaluation. This output is always initialized to 0 (= no result) at the start of the check time.\

Result	Limit value	bResult	Notes
less than	gc_Parameters.rLimitResultWell	1	Good preheating process
less than	gc_Parameters.rLimitResultNormal	2	Normal preheating process
greater than or equal to	gc_Parameters.rLimitResultNormal	3	Poor preheating process

Output xActive

This output is used to indicate the state of the output ‘xClockActive’ of the FB ‘ClockSlave32’ (Off = FALSE, On = TRUE). It is updated permanently independently of the state of xEn (= general enable of the switch-on optimization). \

Output uiDeadTime

This output is used to indicate the current dead time duration (min). This output is always initialized to 0 min at the start of the check time. \

Output uiHeatTime

This output is used to indicate the current heating time duration (min). This output is always initialized to 0 min at the start of the check time. \

Output uiNumber

This output is used to indicate the total number of successful preheating processes. \

Output rAverageDiff

This output is used to indicate the average absolute room temperature deviation of the last 10 successful preheating processes. This output is always updated after the output bResult is updated. This output is initialized to 0 K at each rising signal edge at the input xResAdapt . \

Meaningful use of the output rAverageDiff

This output can be used in combination with the input xResAdapt (reset of the historical memory) to trigger reinitialization of the historical and current data in case of larger deviations.\

1st preheating process

After the software download or after each rising signal edge at the input xResAdapt the historical data are reinitialized. The dead times are written with the parameter uiDTMax, the heating gradients with the parameter uiHGMax and the number of successful preheating processes with the value 0. \

Parameter uiHGMin

This parameter is used to define the minimum permissible heating gradient (min/K). It is used to check for limit violations. In the event of a limit violation, the historical data are not updated. \

Parameter uiHGMax

This parameter is used to define the maximum permissible heating gradient (min/K). It is used to check for limit violations. In the event of a limit violation, the historical data are not updated. \

Parameter uiDTMin

This parameter is used to define the minimum permissible dead time (min). It is used to check for limit violations. In the event of a limit violation, the historical data are not updated. \

Parameter uiDTMax

This parameter is used to define the maximum permissible dead time (min). It is used to check for limit violations. In the event of a limit violation, the historical data are not updated. \

Parameter uiHTMin

This parameter is used to define the minimum permissible heating time (min). It is used to check for limit violations. \

Parameter uiHTMax

This parameter is used to define the maximum permissible heating time (min). It is used to check for limit violations. On each occurrence of a limit violation, the preheating process is stopped and the ‘Off / Deactivated’ phase is initiated. \

Global variable gc_Parameters.rTOMin

This global variable is used to define the minimum permissible outdoor temperature (°C). It is used for checking and correcting limit violations. \

Global variable gc_Parameters.rTOMax

This global variable is used to define the maximum permissible outdoor temperature (°C). It is used for checking and correcting limit violations. \

Global variable gc_Parameters.rTIMin

This global variable is used to define the minimum permissible room temperature (°C). It is used for checking and correcting limit violations. \

Global variable gc_Parameters.rTIMax

This global variable is used to define the maximum permissible room temperature (°C). It is used for checking and correcting limit violations. \

Global variable gc_Parameters.rDiffSetTemp

This global variable is used to define the deviation from the room setpoint temperature at the end of the preheating process (K). It specifies how closely the room temperature must approach the setpoint temperature in daytime/comfort operation in order to end the active preheating process. \

Global variable gc_Parameters.rDTDiffTemp

This global variable is used to define the increase in room temperature to detect the end of the dead time (K). It specifies how much the room temperature must permanently increase during the dead time in order to initiate the heating time. \

Global variable gc_Parameters.uiPHMaxTime

This global variable is used to define the maximum duration of the preheating process. It is used for internal calculations. \

Global variable gc_Parameters.rLimitResultWell

This global variable is used to define the limit ‘Good preheating process’ for the quality display bResult. \

Global variable gc_Parameters.rLimitResultNormal

This global variable is used to define the limit ‘Normal preheating process’ for the quality display bResult.\

Typical application

This function block can be used as follows:

CODESYS

InOut:

Scope	Name	Type	Initial	Inherited from
Input	itfFromClockMaster32	IUhrProtocol		Uhr_Base
Input	ClockSlaveParam	stSlvClockData
Input	xEn	BOOL	FALSE
Input	xEnAdapt	BOOL	TRUE
Input	xResAdapt	BOOL	FALSE
Input	rTo	REAL
Input	rTi	REAL
Input	rSetTemp	REAL
Output	xDaytime	BOOL	FALSE
Output	xProcess	BOOL	FALSE
Output	bState	BYTE	0
Output	wError	WORD	0
Output	bResult	BYTE	0
Output	xActive	BOOL	FALSE
Output	uiDeadTime	UINT	0
Output	uiHeatTime	UINT	0
Output	uiNumber	UINT	0
Output	rAverageDiff	REAL	0.0
Input Const	uiHGMin	UINT	30
Input Const	uiHGMax	UINT	240
Input Const	uiDTMin	UINT	10
Input Const	uiDTMax	UINT	180
Input Const	uiHTMin	UINT	15
Input Const	uiHTMax	UINT	600