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| Joined: | Wednesday Aug 9th, 2006 |
| Location: | Singapore |
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If the Flag assigned to the thermostat is ON, then the thermostat is enabled. If it is off, then Heating and Cooling outputs will be off and the thermostat is disabled.
This works by comparing the setpoint with the actual temperature for each Thermostat.
In cooling mode, if the actual temperature is higher than the setpoint + hystereris, the cooling is turned on (and heating off) using an output. If the temperature is lower than setpoint - hysteresis, the cooling is turned off. The hysteresis prevents constant switching between on and off.
In heating mode, the opposite applies. If the temperature is lower than the setpoint, the heating is turned on (and cooling off) until the temp rises to the setpoint. When the temp falls below the setpoint - hysteresis, the heating is turned on again
Heating and cooling cannot be switched on at the same time (interlocking)
The flowchart is shown below. The sequence is triggred by a change in Sensor value (Temperature), a change in the setpoint (counter) value or a change in state of the Flag (on.off).
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