FB_HVACOutsideTempDamped

Application

This function block serves to determine the average or damped outside temperature. In automatic mode the mean outside temperature is calculated from the outside temperature values at 7:00, 14:00 and 21:00. The measurement taken at 21:00 receives double the weighting.

VAR_INPUT

bEnable             : BOOL;
rOutsideTemp        : REAL;
dtSystemTime        : DT;
bResetInternalValue : BOOL;
eCtrlMode           : E_HVACCtrlMode;
rManualValue        : REAL;

bEnable: the function block is enabled by the PLC program with the input variable bEnable. If bEnable = FALSE, the last valid value of the damped outside temperature is output.

rOutsideTemp: this input variable transfers the current outside temperature to the function block.

dtSystemTime: this input variable transfers the date and time to the function block.

bResetInternalValues: using this input variable, the internally stored outside temperatures are reset and the current outside temperature is then adopted.

eCtrlMode: the operation mode is selected via this enum. Manual or automatic operation mode.

rManualValue: manual value that is set at the output rOutsideTempDamped if eCtrlMode = eHVACCtrlMode_Manual.

VAR_OUTPUT

rOutsideTempDamped      : REAL;

rOutsideTempDamped: damped outside temperature.