OptStartHeat

OptStartHeat (FB)

FUNCTION_BLOCK OptStartHeat

Short description

Start-up optimization for heating operation with an internal weekly timer (principle: variable preheat 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
xEn	BOOL		FALSE	General enable for the switch-on optimization
xEnAdapt	BOOL		TRUE	Enable for data storage in the historical memory
xResAdapt	BOOL		TRUE	Reset of the historical memory
rTo	REAL			Current outside 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 of 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/disabled, 1 = test 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 weekly timer's 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)
todMonFrom	TOD		TOD#07:00	Switch-on time - Monday
todMonTo	TOD		TOD#12:00	Switch-off time - Monday
xMonMode	BOOL		TRUE	Mode - switching period - Monday
todTueFrom	TOD		TOD#07:00	Switch-on time - Tuesday
todTueTo	TOD		TOD#12:00	Switch-off time - Tuesday
xTueMode	BOOL		TRUE	Mode - switching period - Tuesday
todWedFrom	TOD		TOD#07:00	Switch-on time - Wednesday
todWedTo	TOD		TOD#12:00	Switch-off time - Wednesday
xWedMode	BOOL		TRUE	Mode - switching period - Wednesday
todThuFrom	TOD		TOD#07:00	Switch-on time - Thursday
todThuTo	TOD		TOD#12:00	Switch-off time - Thursday
xThuMode	BOOL		TRUE	Mode - switching period - Thursday
todFriFrom	TOD		TOD#07:00	Switch-on time - Friday
todFriTo	TOD		TOD#12:00	Switch-off time - Friday
xFriMode	BOOL		TRUE	Mode - switching period - Friday
todSatFrom	TOD		TOD#07:00	Switch-on time - Saturday
todSatTo	TOD		TOD#12:00	Switch-off time - Saturday
xSatMode	BOOL		TRUE	Mode - switching period - Saturday
todSunFrom	TOD		TOD#07:00	Switch-on time - Sunday
todSunTo	TOD		TOD#12:00	Switch-off time - Sunday
xSunMode	BOOL		TRUE	Mode - switching period - Sunday
sNotice	STRING		'Personal note - click to edit.'	Label - time switch

Global variables

Name	Data type	Value range	Initial value	Function
gc_Parameters.rTOMin	REAL		-25	Minimum value - outside temperature (°C)
gc_Parameters.rTOMax	REAL		25	Maximum value - outside 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 of the 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 - threshold for a good preheating process
gc_Parameters.rLimitResultNormal	REAL		1	Result display: room temperature deviation - threshold for a normal preheating process

Function description

The output xDaytime when switch-on optimization is generally enabled (xEn = TRUE) is activated before the planned start of comfort/daytime operation depending on historical data, the current outside 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 matches the desired setpoint at the start of daytime operation. The required preheating time is recalculated for each preheating process individually recalculated, the actual preheat time is additionally fed into the historical data. Preheating processes spanning multiple days are possible. The start-up optimization serves energy saving and increased user comfort. The components relevant for the start-up optimization are processed every 60 s. The preheating process is divided into four time segments. They are run through sequentially during each successful preheating process. The preheating process can end before, exactly at, or after the switch-on point (= transition to comfort/day operation).

Check time (bState = 1)

The check time serves for cyclical checking (every 60 s) whether the conditions for enabling preheating are met. It begins if the following conditions are met simultaneously:

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

2. The weekly timer is not active (xActive = FALSE)

3. There exists a valid next switching point

It ends properly if the conditions for enabling preheating are met (= start of dead time). It ends in any case if the next valid switching point equals the current time.

Dead time (bState = 2)

The dead time serves 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 persistently for at least 120 s (= start of heating time). It ends in any case if the next valid switching point equals the current time.

Heating time (bState = 3)

The heating time serves to preheat 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 within a duration of at least 120 s to a difference smaller than the global variable gc_Parameters.rDiffSetTemp approaches. It ends if a falling signal edge occurs on the state of the weekly timer's clock channel xActive is detected. It ends if the current heating time duration exceeds the adjustable maximum value uiHTMax .

End of heating time (bState = 4)

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

Enable xEn

This input serves as the general enable for 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 remain preserved even in the locked state. This input can also be used to map sensor faults (fault - room temperature sensor, fault - outside temperature sensor) or for operating the zone in extended occupancy mode.

Enable xEnAdapt

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

Enable xResAdapt

This input serves to initialize the historical memory on 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 memory 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 a reinitialization of the historical and current data in case of larger deviations.

Input rTo

This input is used to capture the current outside temperature. It is additionally time-filtered and limited for the switch-on optimization (minimum value = gc_Parameters.rTOMin, maximum value = gc_Parameters.rTOMax ).

Input rTi

This input is used to capture the current room temperature. It is additionally time-filtered and limited for the switch-on optimization (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. On every change of the setpoint temperature a reset to the default state occurs (see Enable - locked state). xEn This output serves to enable comfort/daytime operation (Off = FALSE, On = TRUE)

Output xDaytime

by the switch-on optimization . It is activated upon transition from the check time to the dead time. It is deactivated if the next valid switching point is reached.This output serves to indicate an active preheating process (Off = FALSE, On = TRUE). It is active if the preheating process is in phases 1 - 4 and/or the output

Output xProcess

is active. xDaytime This output serves to indicate the active phase of the preheating process.

Output bState

Phase

Value	Off / Deactivated
0	Check time active
1	Dead time active
2	Heating time active
3	End of heating time active
4	This output serves 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 updated continuously. On every change the date / current time is also recorded. This output is always initialized to 0 (= no error) at the start of the check time. On every occurrence of an error the preheating process is stopped and the phase 'Off / Deactivated' is initiated. On every occurrence of a warning the output

Output wError

is updated. wError Bit

Cause	Error type	Exceeding the maximum heating time	Notes
1	Error	Limit violation heating gradient
4	Warning	Limit violation dead time
5	Undershooting the minimum heating time	Limit violation dead time
6	This output serves to indicate the quality of the last successful preheating process. The output is updated at the switching point (= transition to comfort/daytime operation) if necessary. The absolute value from the calculation of	Limit violation dead time

Output bResult

is used for the assessment. This output is always initialized to 0 (= no result) at the start of the check time. rSetTemp - gc_Parameters.rDiffSetTemp - rTi Result

Threshold	less than	bResult	Notes
Good preheating process	gc_Parameters.rLimitResultWell	1	Normal preheating process
Good preheating process	gc_Parameters.rLimitResultNormal	2	greater or equal
Poor preheating process	gc_Parameters.rLimitResultNormal	3	This output serves to indicate the state of the output 'xClockActive' of the FB 'ClockSlave32' (Off = FALSE, On = TRUE). It is updated continuously regardless of the state of

Output xActive

This output is used to indicate the state of the weekly timer's clock channel (Off = FALSE, On = TRUE). The weekly timer is continuously updated regardless of the state of xEn (= general enable for the start-up optimization). When the weekly timer settings are changed, a reset to the default state occurs (see enable xEn This output serves to enable comfort/daytime operation (Off = FALSE, On = TRUE)

Output uiDeadTime

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

Output uiHeatTime

This output serves to display the total number of successful preheating processes.

Output uiNumber

This output serves to display the average absolute room temperature deviation of the last 10 successful preheating processes. This output is always updated after the update of the output

Output rAverageDiff

is updated. This output is initialized to 0 K on every rising signal edge at the input bResult with 0 K. xResAdapt Meaningful use of the output

This output can be used in combination with the input rAverageDiff

(Reset of the historical memory) to trigger a reinitialization of the historical and current data in case of larger deviations. xResAdapt 1. Preheating process

After the software download or after each rising signal edge at the input

the historical data are reinitialized. The dead times are described by the parameter xResAdapt , the heating gradients by the parameter uiDTMaxand the number of successful preheating processes with the value 0. uiHGMax Parameter

This parameter serves to define the minimum allowable heating gradient (min / K). It is used to check for limit violations. In case of a limit violation the historical data are not updated. uiHGMin

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

This parameter serves to define the minimum allowable heating gradient (min / K). It is used to check for limit violations. In case of a limit violation the historical data are not updated. uiHGMax

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

This parameter serves to define the minimum allowable heating gradient (min / K). It is used to check for limit violations. In case of a limit violation the historical data are not updated. uiDTMin

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

This parameter serves to define the minimum allowable heating gradient (min / K). It is used to check for limit violations. In case of a limit violation the historical data are not updated. uiDTMax

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

This parameter serves to define the minimum allowable heating gradient (min / K). It is used to check for limit violations. In case of a limit violation the historical data are not updated. uiHTMin

This parameter serves to define the maximum allowable heating time (min). It is used to check for limit violations. On every occurrence of a limit violation the preheating process is stopped and the phase 'Off / Deactivated' is initiated.

This parameter serves to define the minimum allowable heating gradient (min / K). It is used to check for limit violations. In case of a limit violation the historical data are not updated. uiHTMax

Global variable

This parameter serves to define the minimum allowable heating gradient (min / K). It is used to check for limit violations. In case of a limit violation the historical data are not updated. todMonFrom - sNotice

This parameter is used to configure the weekly timer. The general functionality is described in detail in the documentation of the function block 'Clock7d1Ch'.

This global variable serves to define the minimum allowable outside temperature (°C). It is used to check and correct limit violations. gc_Parameters.rTOMin

This global variable serves to define the maximum allowable outside temperature (°C). It is used to check and correct limit violations.

This global variable serves to define the minimum allowable outside temperature (°C). It is used to check and correct limit violations. gc_Parameters.rTOMax

This global variable serves to define the minimum allowable room temperature (°C). It is used to check and correct limit violations.

This global variable serves to define the minimum allowable outside temperature (°C). It is used to check and correct limit violations. gc_Parameters.rTIMin

This global variable serves to define the maximum allowable room temperature (°C). It is used to check and correct limit violations.

This global variable serves to define the minimum allowable outside temperature (°C). It is used to check and correct limit violations. gc_Parameters.rTIMax

This global variable serves to define the deviation from the room setpoint temperature at the end of the preheating process (K). It defines how close the room temperature must approach the setpoint temperature in daytime/comfort operation to terminate the active preheating process.

This global variable serves to define the minimum allowable outside temperature (°C). It is used to check and correct limit violations. gc_Parameters.rDiffSetTemp

This global variable serves to define the increase of the room temperature to detect the end of the dead time (K). It defines how much the room temperature must increase persistently during dead time to initiate the heating time.

This global variable serves to define the minimum allowable outside temperature (°C). It is used to check and correct limit violations. gc_Parameters.rDTDiffTemp

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

This global variable serves to define the minimum allowable outside temperature (°C). It is used to check and correct limit violations. gc_Parameters.uiPHMaxTime

This global variable serves to define the threshold 'Good preheating process' for the quality display

This global variable serves to define the minimum allowable outside temperature (°C). It is used to check and correct limit violations. gc_Parameters.rLimitResultWell

This global variable serves to define the threshold 'Normal preheating process' for the quality display bResult.

This global variable serves to define the minimum allowable outside temperature (°C). It is used to check and correct limit violations. gc_Parameters.rLimitResultNormal

Typical application bResult.

This function block can be applied as follows:

This function block can be applied as follows:

CODESYS

InOut:

Scope	Name	Type	Initial
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
Input Const	todMonFrom	TOD	TIME_OF_DAY#7:0
Input Const	todMonTo	TOD	TIME_OF_DAY#18:0
Input Const	xMonMode	BOOL	TRUE
Input Const	todTueFrom	TOD	TIME_OF_DAY#7:0
Input Const	todTueTo	TOD	TIME_OF_DAY#18:0
Input Const	xTueMode	BOOL	TRUE
Input Const	todWedFrom	TOD	TIME_OF_DAY#7:0
Input Const	todWedTo	TOD	TIME_OF_DAY#18:0
Input Const	xWedMode	BOOL	TRUE
Input Const	todThuFrom	TOD	TIME_OF_DAY#7:0
Input Const	todThuTo	TOD	TIME_OF_DAY#18:0
Input Const	xThuMode	BOOL	TRUE
Input Const	todFriFrom	TOD	TIME_OF_DAY#7:0
Input Const	todFriTo	TOD	TIME_OF_DAY#18:0
Input Const	xFriMode	BOOL	TRUE
Input Const	todSatFrom	TOD	TIME_OF_DAY#7:0
Input Const	todSatTo	TOD	TIME_OF_DAY#18:0
Input Const	xSatMode	BOOL	TRUE
Input Const	todSunFrom	TOD	TIME_OF_DAY#7:0
Input Const	todSunTo	TOD	TIME_OF_DAY#18:0
Input Const	xSunMode	BOOL	TRUE
Input Const	sNotice	STRING	‘Notice’