FB_BA_RmTAdj

Functional description

The function block FB_BA_RmTAdj is used to adjust the room temperature setpoint from the user in the room. It shifts the setpoints at the input of a function block depending on an offset rRmTAdj, as shown in the following diagram. At the rRmTAdj input, the value of a resistance potentiometer or a bus-capable field device can be used for the setpoint correction.

If the set value rRmTAdj is greater than zero, room temperature heating is desired: the Comfort Heating value is increased by the value rRmTAdj. At the same time, the values for Comfort Cooling and PreComfort Cooling are increased. If the value rRmTAdj is less than zero, a lower room temperature is requested. Analogous to the heating case, the values for Comfort Cooling, Comfort Heating and PreComfort Heating are now reduced by the value rRmTAdj.

Auto-correction

The temperature adjustment is intended for small corrections of the values. Although it is possible to enter any input values, a heating system will only work in a meaningful manner if the setpoints have ascending values in the following order:

• Protection Heating
• Economy Heating
• Precomfort Heating
• Comfort Heating
• Comfort Cooling
• Precomfort Cooling
• Economy Cooling
• Protection Cooling

The auto-correction is based on the principle that, starting from the value for Economy Heating, the system checks whether this value is smaller than the next lower parameter, in this case Protection Heating. If this is the case, the value for Economy Heating is adjusted to match the value for Protection Heating. The system then checks whether the value for Precomfort Heating is less than Economy Heating and so on, until the value for Protection Cooling is compared with the value for Economy Cooling. If one or several values were corrected, this is indicated with a TRUE signal at output bValCorr.

VAR_INPUT

lrRmTAdj : LREAL;
stSp     : ST_BA_SpRmT;

lrRmTAdj: Room temperature offset value

stSp : Input structure for the setpoints

VAR_OUTPUT

bValCorr      : BOOL;
rPrPrtcHtg    : REAL;
rPrEcoHtg     : REAL;
rPrPreCmfHtg  : REAL;
rPrCmfHtg     : REAL;
rPrPrtcCol    : REAL;
rPrEcoCol     : REAL;
rPrPreCmfCol  : REAL;
rPrCmfCol     : REAL;
stPrSp        : ST_BA_SpRmT;

bValCorr: autocorrection for the values was performed, see above

rPrPrtcHtg: resulting Protection Heating setpoint

rPrEcoHtg: resulting Economy Heating setpoint

rPrPreCmfHtg: resulting PreComfort Heating setpoint

rPrCmfHtg: resulting Comfort Heating setpoint

rPrCmfCol: resulting Comfort Cooling setpoint

rPrPreCmfCol: resulting PreComfort Cooling setpoint

rPrEcoCol: resulting Economy Cooling setpoint

rPrPrtcCol : resulting Protection Cooling setpoint

stPrSp: consolidated output of the resulting values in a structure 

Requirements