Echelon NodeBuilder FX/PL Examples - Manual (Page 34)

26 Using the NodeBuilder FX/PL Example
else if ((TFblock_command)iCommand == FBC_WHEN_RESET)
HVACTempOld = 0;
UpdateTemperature();
//
get going:
setLockedOutBit(uFblockIndex, FALSE);
break;
10. Still in TempSensor.nc, add the following functions to the code:
#endif //_HAS_INPUT_NV_
int cmptime ( const SNVT_elapsed_tm * const a, const unsigned long b ) {
unsigned long ulA;
int iResult;
// convert SNVT_elapsed_tm_a into a value of type(b).
ulA = a->millisecond;
ulA += (1000uL / HVAC_CORETICK)
* ( a->second + 60UL * (a->minute + 60ul
* (a->hour + 24ul * a->day)));
if (b > ulA) {
iResult = -1;
} else if (b < ulA) {
iResult = +1;
} else {
iResult = 0;
}
return
iResult;
}
void PropagateTemp(const SNVT_temp_p Value) {
float_type fTemp, fResult;
// set the temp_p type nvo:
TempSensor::nvoHVACTemp = Value;
// convert to float.
// Get the float_type representation of the scaled
//temp_p value:
fl_from_slong(Value, &fTemp);
// Get it right by correcting the fixed decimal point:
fl_div(&fTemp, &f100, &fResult);
// That's it!
TempSensor::nvoFloatTemp = fResult;
// restart the minsend/maxsend timers
HvacMinSendTimer = HvacMaxSendTimer = 0L;
}
void UpdateTemperature(void) {
// Get new value
SNVT_temp_p NewValue;
NewValue = GizmoReadTemperature(FALSE, TRUE);
// Transmit if new value varies by more than nciMinDelta from
// old value:
if ((NewValue < (HVACTempOld - TempSensor::nvoHVACTemp::cpMinDelta))
|| (NewValue > (HVACTempOld
+ TempSensor::nvoHVACTemp::cpMinDelta))) {
// Even so, only transmit if nciMinSendTimer allows:
if (cmptime((const SNVT_elapsed_tm * const)
&(TempSensor::cpMinSendTime), HvacMinSendTimer) <= 0 ) {
// min send time has expired, really send data now:
PropagateTemp(NewValue);
}
}
// In either case, make sure to keep record of the latest value:
HVACTempOld = NewValue;
}