The thermostat has 2 multifunctional inputs X1 and X2.
An NTC type sensor like the QAH11.1 (AI, analog input) or a switch (DI, digital input) can be connected to the input terminals. The functionality of the inputs can be configured via parameters P38 + P39 for X1 and P40 + P41 for X2.
The current temperature or state of the inputs X1/X2 is available on bus for monitoring purposes.
The parameters can be set to the following values:
| # | Function of input | Description | Type X1/X2 | |
|---|---|---|---|---|
| 0 | Not used | No function. | -- | |
| 1 | External / return air temperature | Sensor input for external room temperature sensor or return air temperature sensor to acquire the current room temperature, or floor heating temperature sensor to limit the heating output. Note: The room temperature is acquired by the built-in sensor if the floor temperature limitation function is enabled via parameter P51. |
AI | |
Heating/ cooling changeover |
2 | Heating / cooling changeover | Sensor input for "Automatic heating / cooling changeover" function. A switch can also be connected rather than a sensor Important: Switch closed means always cooling, (this cannot be changed), see section 3.5. Heating / cooling changeover is also possible via bus. In this case, the function must not be assigned to any local input X1, X2. See also section 3.5. Diagnostic value 00 is displayed for closed contact / |
AI / DI |
Window state (RDF600..) |
3 | Window contact (RDF600KN…) 1) |
Window contact input to switch the operating mode to Protection. If the window contact is open, user operations are ineffective and "OFF" is displayed. Window contact is also possible via bus. In this case, the function must not be assigned to any local input X1, X2. See also section 3.2.1. |
DI |
(RDF301..) |
3 | Operating mode switchover (RDF301..) |
Digital input to switch over the operating mode to Economy. If the operating mode switchover contact is active, user operations are ineffective and "OFF" is displayed. Operating mode switchover is also possible via bus. In this case, the function must not be assigned to any local input X1, X2. See also section 3.2.1. |
DI |
| 4 | Dew point monitor | Digital input for a dew point sensor to detect condensation. Cooling is stopped if condensation occurs. | DI | |
Enable electric heater |
5 | Enable electric heater | Digital input to enable / disable the electric heater via remote control. Enable electric heater is also possible via bus. In this case, the function must not be assigned to any local input X1, X2. See also section 3.6. |
DI |
Fault information |
6 | Fault | Digital input to signal an external fault (example: dirty air filter). If the input is active, "ALx" is displayed and a fault is sent on the bus. See also section 3.11.8. Note: Fault displays have no impact on the thermostat's operation. They merely represent a visual signal. |
DI |
X1, X2 (Digital) |
7 | Monitor input (Digital) | Digital input to monitor the state of an external switch via bus, e.g. to send a local alarm via KNX to the central controller. | DI |
X1, X2 (Temp.) |
8 | Monitor input (Temperature) | Sensor input to monitor the state of an external sensor (e.g. QAH11.1) via bus, e.g. to send a local temperature (0...49°C) via KNX to the central controller. | AI |
(RDF600…) |
10 | Presence detector (RDF600KN…) 1) |
Standard presence: Presence detector input to switch the operating mode to Comfort in case of occupancy and back to Economy when the room is unoccupied. Hotel presence: Presence detector input to change the operating mode from Economy during unoccupied periods to the previous mode (operating mode selected by either hotel guests via local HMI or sent via bus) for occupancy and return to Economy when the room is unoccupied. Presence detector is also possible via bus. In this case, the function must not be assigned to any local input X1, X2. See also section 3.2.1. |
DI |
Operational action can be changed between normally open (NO) and normally closed (NC) via parameter P39, P41.
Each input X1 or X2 must be configured with a different function (1…5, 10). Exception: 1 or 2 inputs can be configured as fault (6) or monitor input (7, 8).
X1 is factory-set to "Operating mode switchover" / "Window contact" (3), X2 to "External sensor" (1).
Note 1):
RDF600KN, RDF600KN/VB SW version < V1.8 works like RDF301… with the operating mode switchover contact as window contact or presence detector.
For more detailed information, refer to section 3.4.