FB_BARSetpointRoom

Application

The function block FB_BARSetpointRoom assigns setpoints for cooling and heating operation to each of the energy levels Protection, Economy, PreComfort and Comfort. In connection with the function block FB_BAREnergyLevel the room temperature controllers are assigned an energetically optimum setpoint in accordance with the use of the room and the selected heating or cooling operation.

The resulting setpoint for the different energy levels is made up of:

1. the base setpoint value

2. the local setpoint value shift (not in the case of the Protection setpoints)

3. the central setpoint value shift (not in the case of the Protection setpoints)

The local shift due to a room setpoint generator and also the remote adjustment of the setpoints by a building management system only affect the Comfort and PreComfort energy levels.

VAR_INPUT

eDataSecurityType : E_HVACDataSecurityType;
bSetDefault       : BOOL;
bEnable           : BOOL;
rSetpointShiftHeat: REAL; 
rSetpointShiftCool: REAL;
rSetpointShiftUser: REAL;  
bReset            : BOOL; 

eDataSecurityType:if eDataSecurityType:= eHVACDataSecurityType_Persistent, the persistent VAR_IN_OUT variables of the function block are stored in the flash of the computer if a value changes. For this to work, the function block FB_HVACPersistentDataHandling must be instanced once in the main program, which is called cyclically. Otherwise the instanced FB is not released internally.

A change of value can be initiated by the building management system, a local operating device or via a write access from TwinCAT. When the computer is restarted, the saved data are automatically read back from the flash into the RAM.

If eDataSecurityType:= eHVACDataSecurityType_Idle the persistently declared variables are not saved in a fail-safe manner.

bSetDefault: If the variable is TRUE, the default values of the VAR_IN_OUT variables are adopted.

bEnable: The function block is activated if the variable bEnable is TRUE.

rSetpointShiftHeat: The rSetpointShiftHeat variable is used for the adaptation of the ComfortHeating setpoint of the building management system.

If the ComfortHeating setpoint is raised, then the setpoints for the ComfortCooling and PreComfortCooling are also increased.
Example:

A lowering of the ComfortHeating setpoint affects only the ComfortHeating and PreComfortHeating setpoints.
Example:

rSetpointShiftCool: The rSetpointShiftCoolvariable is used for the adaptation of the ComfortCooling setpoint of the building management system.

If the ComfortCooling setpoint is raised, then the setpoint for the PreComfortCooling is also raised.
Example:

A lowering of the ComfortCooling setpoint only affects the ComfortCooling. The PreComfortCooling is not changed.
Example:

If the setpoint of the PreComfort energy level is shifted beyond the setpoint of the Economy level, then the setpoint of the Economy level adopts the value of the PreComfort level.
Example:

rSetpointShiftUser: The variable rSetpointShiftUser is used for local setpoint shifting of the user.
A positive value of rSetpointShiftUser affects the setpoint of ComfortHeating, ComfortCooling and PreComfortColling.
Example:

A negative value of rSetpointShiftUser affects the setpoints of PreComfortHeating, ComfortHeating and ComfortCooling.
Example:

bReset: Acknowledge input in case of a fault or an incorrect parameter.

VAR_OUTPUT

stSetpoint       : ST_BARSetpointRoom; 
bInvalidParameter: BOOL; 

stSetpoint: Structure containing the setpoints for all energy levels.

bInvalidParameter: Indicates that an incorrect input parameter is present. bInvalidParameter must be acknowledged with bReset.

VAR_IN_OUT

rSetpointComfortHeat        : REAL;
rSetpointPreComfortHeat     : REAL;
rSetpointEconomyHeat        : REAL;
rSetpointProtectionHeat     : REAL;
rSetpointComfortCool        : REAL;
rSetpointPreComfortCool     : REAL;
rSetpointEconomyCool        : REAL;
rSetpointProtectionCool     : REAL;

rSetpointComfortHeat: Setpoint for the Comfort heating energy level. The variable is saved persistently. Preset to 21.0.

rSetpointPreComfortHeat: Setpoint for the PreComfort heating energy level. The variable is saved persistently. Preset to 19.0.

rSetpointEconomyHeat: Setpoint for the Economy heating energy level. The variable is saved persistently. Preset to 15.0.

rSetpointProtectionHeat: Setpoint for the Protection heating energy level. The variable is saved persistently. Preset to 12.0.

rSetpointComfortCool: Setpoint for the Comfort cooling energy level. The variable is saved persistently. Preset to 24.0.

rSetpointPreComfortCool: Setpoint for the PreComfort cooling energy level. The variable is saved persistently. Preset to 28.0.

rSetpointEconomyCool: Setpoint for the Economy cooling energy level. The variable is saved persistently. Preset to 35.0.

rSetpointProtectionCool: Setpoint for the Protection cooling energy level. The variable is saved persistently. Preset to 40.0.