Basic Documentation

Functions
Multifunctional input, digital input
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A6V12114068_en--_c
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Function of input
Description
Type
B1/S1/X1/
X2
X1 input, X2 input
7
Monitor input (digital)
(RDF660MB only)
Digital input to monitor the state of an external
switch via Modbus
DI
X1 input, X2 input
8
Monitor input (analog)
(RDF660MB only)
Sensor input to monitor the state of an external
sensor (e.g., NTC 3k) via Modbus.
AI
Heating/
cooling
changeover
9
Heating/cooling
changeover
Digital input for "Automatic heating/cooling
changeover" function.
A switch instead of a sensor can also be
connected. (Switch closed = cooling, see
Additional functions [➙ 26]
Heating/cooling changeover is also possible via
Modbus. In this case, do not be assigned to the
function to local inputs B1/X1, S1/X2. See also
Additional functions [➙ 26].
Diagnostic value 0 ˚C is displayed for a closed
contact, 100 ˚C for an open contact, if a switch
is connected.
DI
Presence detector
10
Presence detector
The presence detector input switches the
operating mode to Comfort when the room is
occupied and returns to the previous operating
mode when the room is unoccupied.
Presence detector is also possible via bus. In
this case, do not assign the function to local
inputs B1/X1, S1/X2. See also Hotel
keycard/Presence detector [➙ 28].
DI
Hotel keycard
11
Hotel keycard
The hotel keycard input switches the operating
mode to Economy with HMI locked when the
room is unoccupied, and returns to the previous
operating mode when the room is occupied.
Hotel keycard is also possible via bus. In this
case, do not assign the function to local input
S1/X1/X2. See also Hotel keycard/Presence
detector [➙ 28].
DI
● The control action can be changed from 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 &
9…11). Exception: 1 or 2 inputs can be configured as fault (6) or monitor input
(7,8).
● RDF660MB/MM only: B1 is factory-set to "H/C changeover (DI)" (9), S1 to
"Window contact" (3).
● RDF660MB only: X1 is factory-set to "Window contact" (3), X2 to "Room
temperature external sensor/return air temperature" (1).
If a multifunctional input is configured as analog: "Er3" is displayed when the output
is out of range (0...49 °C), open or shorted.
For detailed information, see Application overview [➙ 22].
● For inputs B1/X1 and S1/X2, one physical switch can be used for up to 20
thermostats (parallel connection).
Caution! Do not mix B1/X1 and S1/X2.
● For sensors on inputs B1/X1 or S1/X2, the maximum cable length is 80 m.
Note