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Siemens
RDU340… Basic Documentation
CE1P3078en
Building Technologies
Functions
2014-11-03
4.8 Multifunctional
input
The controller offers two multifunctional inputs X1 and X2. A sensor of type NTC
like QAH11.1 (AI) or a switch (DI) can be connected to the input terminals. The
functionality of both inputs can be configured via parameters P38 for input X1 and
P40 for input X2.
#
Function of input X1/X2
Description
Type
0 Not
used
No function.
-
1 External/Return air temp.
Sensor input external room
temperature sensor or return air
temperature sensor to measure the
current room temperature.
AI
2 Heat/cool
changeover
Sensor input for automatic
heating/cooling changeover
function. A switch can also be
connected rather than a sensor.
AI/(DI)
3
Operating mode switchover Digital input to switch over the
operating mode to Energy Saving.
If the operating mode switchover
contact is active, user operations
are ineffective and “OFF” is
displayed.
DI
4 Dewpoint
monitor
Digital input for a dewpoint sensor
to detect condensation. Cooling is
stopped if condensation occurs.
DI
5 Enable electrical heater
Digital input to enable/disable the
electrical heater via remote control.
DI
6 Alarm
Digital input to signal an alarm.
If the input is active, “ALx”
(x:=1 or 2)
is displayed.
Note: Alarm displays do not influ-
ence controller operations. They
merely represent a visual signal.
Example:
No air flow or el. heater
overheated.
DI
Operational action can be changed between normally open (N.O.) and normally
closed (N.C.) via parameter P39 or P41 if it is a digital input (DI).
Each function can only be assigned to input X1 or X2; only “Alarm” can be
assigned to both inputs.
X1 is factory-set to “Operating mode switchover” (3) and X2 to “Heating/cooling
changeover” (2).
For more information see section 4.4 “Applications”.
